U.S. patent application number 12/053436 was filed with the patent office on 2009-07-30 for method and apparatus for an improved security system mechanism in a business applications management system platform.
Invention is credited to Daniel S. Lipkin, Gaurav Mehra.
Application Number | 20090192847 12/053436 |
Document ID | / |
Family ID | 22643206 |
Filed Date | 2009-07-30 |
United States Patent
Application |
20090192847 |
Kind Code |
A1 |
Lipkin; Daniel S. ; et
al. |
July 30, 2009 |
METHOD AND APPARATUS FOR AN IMPROVED SECURITY SYSTEM MECHANISM IN A
BUSINESS APPLICATIONS MANAGEMENT SYSTEM PLATFORM
Abstract
The present invention provides a solution to the needs described
above through an improved method and apparatus for an improved
security system mechanism in a business applications management
system platform. The security management system partitions a number
of business objects into a number of hierarchical domains. A
security list is then created and configured to grant a member the
right to perform a security operation on the business object
located within the hierarchical domain. The security list is
created by adding the security operation to the security list,
applying the security operation to one of the multiple domains, and
adding members to the security list.
Inventors: |
Lipkin; Daniel S.; (Belmont,
CA) ; Mehra; Gaurav; (Mumbai, IN) |
Correspondence
Address: |
MORRISON & FOERSTER LLP
425 MARKET STREET
SAN FRANCISCO
CA
94105-2482
US
|
Family ID: |
22643206 |
Appl. No.: |
12/053436 |
Filed: |
March 21, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10995867 |
Nov 22, 2004 |
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12053436 |
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09759062 |
Jan 12, 2001 |
6850893 |
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10995867 |
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60176153 |
Jan 14, 2000 |
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Current U.S.
Class: |
726/4 |
Current CPC
Class: |
G06F 21/604 20130101;
H04L 63/101 20130101; G06F 9/468 20130101; G06F 21/6218 20130101;
G06Q 10/063 20130101; Y10S 707/99944 20130101; H04L 2463/102
20130101; Y10S 707/99931 20130101; H04L 63/105 20130101; G06F
21/6236 20130101; G06Q 10/10 20130101; G06F 2221/2141 20130101;
H04L 67/02 20130101; G06Q 20/3821 20130101; H04L 63/083
20130101 |
Class at
Publication: |
705/7 |
International
Class: |
G06Q 10/00 20060101
G06Q010/00 |
Claims
1. A method for managing security on a business application
management platform implemented on a computer, comprising the steps
of: partitioning a plurality of business objects into a plurality
of hierarchical domains; and creating a security list configured to
grant a member the right to perform a security operation on said
business object located in said hierarchical domain, comprising the
steps of: adding said security operation to said security list;
applying said security operation to one of said plurality of
domains; and adding said member to said security list.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 10/995,867, filed Nov. 22, 2004, which is a
continuation of U.S. patent application Ser. No. 09/759,062, filed
Jan. 12, 2001, now issued as U.S. Pat. No. 6,850,893, and which
claims priority to U.S. Provisional Application No. 60/176,153,
filed Jan. 14, 2000, the contents of all of which are incorporated
herein by reference in their entirety.
[0002] This application relates to the following patent
applications filed on Jan. 12, 2001: U.S. patent application Ser.
No. 09/760,068, titled "Method and apparatus for a Business
Applications Server Management System Platform;" U.S. patent
application Ser. No. 09/759,856, titled "Method and apparatus for a
Web Content Platform;" U.S. patent application Ser. No. 09/759,497,
titled "Method and apparatus for a Business Applications Server;"
U.S. patent application Ser. No. 09/760,432, titled "Method and
apparatus for an Information Server;" and U.S. patent application
Ser. No. 09/759,678, titled "Method and apparatus for Managing Data
Exchange Among Systems in a Network."
COPYRIGHT NOTICE
[0003] A portion of this patent document contains material which is
subject to copyright protection. The copyright owner has no
objection to the facsimile reproduction by anyone of the patent
document or the patent disclosure, as it appears in the Patent and
Trademark Office patent file or records, but otherwise reserves all
copyright rights whatsoever.
TECHNICAL FIELD
[0004] The present invention relates to the general field of
computers, telecommunications, and computer and Internet related
systems. More specifically, the invention relates to a computer
security management system for managing security on a business
application management platform.
BACKGROUND
[0005] Today software system developers are providing more
efficient automated systems for managing the processing of
information from multiple, inter-related applications, wherein the
applications may be housed on disparate computer hardware
platforms, in diverse locations, and have multiple domains. One
concern in processing information from multiple, inter-related
applications is security and data integrity.
[0006] Many computer hardware systems, including enhanced security
versions of UNIX, permit access to files, etc to be controlled by
associating with each file a list of the users (and/or groups of
users) who are allowed to access the file, with the types of access
permitted to each. This list is an example of a security list. For
example, a file might have associated with it a security list
indicating whether a user is permitted to read, write, or execute
the file.
[0007] Similarly, computer systems running object-oriented software
utilize a security list having an access control list that grants
one or more privileges to one or more users on one or more objects.
The security list also has a means for confirming that the
particular active user has access rights to a particular object
before permitting the user to access the object. However, the
privilege granted by the security list only pertains to an object
located in a particular domain. In order for a user to have the
same privilege granted in a different domain, the user must be
added to the security list within that domain. Thus prior art
security systems require redundant inputs rendering them
inefficient and difficult to mange by a global administrator.
[0008] Accordingly, there is a need in the art for an improved
computer security management system for managing the applications
housed on disparate hardware platforms in diverse locations. More
specifically, there is a need for a computer security management
system having a decentralized approach for managing security that
allows a global administrator to define complex privileges
containing a set of (privilege, object) pairs that are domain
independent. The current invention provides these facilities in
various new and novel ways as more fully described below.
SUMMARY OF THE INVENTION
[0009] The present invention presents an improved method and
apparatus for an improved security system mechanism in a business
applications management system platform that defines sets of
allowed operations that groups of users can perform across multiple
domains, thus minimizing user input effort. The security management
system partitions a number of business objects into a number of
hierarchical domains. A security list is then created and
configured to grant a member the right to perform a security
operation on the business object located within the hierarchical
domain. The security list is created by adding the security
operation to the security list, applying the security operation to
one of the multiple domains, and adding members to the security
list.
[0010] In one embodiment of the invention, a member is an
individual user, associated with a generic role, and/or associated
with an automated process.
[0011] In another embodiment of the invention, the right to perform
said security operation is shared by more than one member.
[0012] In another embodiment of the invention, the security list is
a global security list configured to apply across multiple
hierarchical domains.
[0013] The present invention presents a computer security
management system for managing security on a business application
management platform. The security system includes a partitioning
mechanism configured to partition multiple business objects into
multiple hierarchical domains. The security system also includes a
security list mechanism configured to create a security list. The
security list mechanism includes a security operation which applies
within a hierarchical domain. The security list mechanism also
includes a member. The security list grants the member the right to
perform the security operation within a hierarchical domain.
[0014] The present invention presents a computer-readable storage
medium containing computer executable code for implementing a
security management system for managing security on a business
application management platform. The executable code instructs a
computer to partition multiple business objects into multiple
hierarchical domains. The executable code then instructs the
computer to create a security list by adding the security operation
to the security list, applying the security list to a hierarchical
domain, and adding the member to the security list. The security
list is configured to grant a member the right to perform the
security operation within a hierarchical domain.
DESCRIPTION OF THE DRAWINGS
[0015] The features and advantages of the system and method of the
present invention will be apparent from the following description
in which:
[0016] FIG. 1 illustrates a typical configuration of Internet
connected systems representative of the preferred embodiment of the
present invention.
[0017] FIG. 2 illustrates a typical general purpose computer system
of the type representative of the preferred embodiment.
[0018] FIG. 3 illustrates the general three tier relationship
between user, web-servers and their related applications-server,
and the database management system.
[0019] FIG. 4 illustrates a more detailed depiction of the
applications-server portion of such a system as shown in FIG. 3
illustrating the business applications platform system of the
present invention.
[0020] FIG. 5 illustrates an alternative configuration of the
system which contains the invention.
[0021] FIG. 6 is an alternative depiction of the platform of the
present invention.
[0022] FIG. 7 illustrates a more detailed configuration of an
exemplary business server portion of the current invention.
[0023] FIG. 8A illustrates a more detailed configuration of an
exemplary Web Content Server portion of the current invention.
[0024] FIG. 8B shows a process flow diagram illustrating how to
produce dynamic web content.
[0025] FIG. 8C shows a process flow diagram illustrating the page
development process.
[0026] FIG. 9 illustrates a preferred embodiment of the
Interconnect Backbone.
[0027] FIG. 10 shows a process flow diagram illustrating a purchase
order delivered from a Source site to a target system through
Interconnect.
[0028] FIG. 11 illustrates one embodiment of the structural
overview of an IDK.
[0029] FIG. 12 illustrates one embodiment of a functional overview
of an Information Distributor.
[0030] FIG. 13 illustrates an exemplary view of APIs associated
with the Information Distributor.
[0031] FIG. 14 illustrates an exemplary view of using Information
Distributor or IDK.
[0032] FIG. 15 illustrates an exemplary overview of Query
Objects.
[0033] FIG. 16 illustrates an exemplary overview of the Implement
Custom Delivery Service.
[0034] FIG. 17 illustrates a preferred embodiment of the Business
Applications Management System Platform.
[0035] FIG. 18 illustrates an exemplary storage scheme relating to
objects.
[0036] FIG. 19 illustrates exemplary transfer of various kinds of
objects to database storage for a persistence mechanism.
[0037] FIG. 20 illustrates an exemplary three-domain
organization.
DETAILED DESCRIPTION
[0038] The present invention provides a solution to the needs
described above through a system and method for integrating the
disparate applications, and managing the applications processes in
a hardware resource and user effort efficient manner. The automated
system of the present invention uses a business systems platform
architecture comprised of several unique servers in a base platform
(the "Platform") to efficiently manage multiple applications which
may themselves generally be distributed across a network. The
platform makes use of a collection of Core Services which provide
additional security, internationalization services, and reporting
services which are applicable to all applications. The Core
Services are made available to a multitude of common business
objects, which themselves are made available to various
applications.
[0039] The present invention is a Business Applications Management
System Platform Architecture (the "Platform" or alternatively the
"SABA architecture") which is designed to maintain and use a set of
unique servers and common objects to generate the set of tasks
required to be performed to complete a designated business
transaction in a concrete, and useful way. In the preferred
embodiment, the platform permits application developers to work on
the business aspects of the application without having to focus on
transaction management, security, persistence of data or life cycle
management of the object itself. The servers and other aspects of
the Platform are described in more detail below. However, a general
overview of a preferred embodiment of the invention is first
described.
(1) General Overview
[0040] The technology used as part of the system currently is, and
will be, able to interface with many other industry standard
software programs to make the exchange and flow of data easy and
accurate.
[0041] The system is predominantly web-enabled, which extends its
use to all industry professionals connected to the Internet. The
Platform provides a unified set of interfaces, an application
Framework, that encompass Business Object development,
Web-application development, external connectivity development, and
information distribution development.
[0042] The system is predominantly based on object-oriented
programming principles as described in "Object-Oriented Software
Construction" by Bertrand Meyer, Prentiss-Hall, 1988, ISBN
0-13-629049-3 and the Sun Microsystems.TM. developed JAVA.TM.
systems described in the following publications: [0043] Enterprise
JavaBeans Specification, v1.1 (can be found at
//java.sun.com/products/ejb/docs.html) [0044] Enterprise JavaBeans,
Richard Monson-Haefel, O'Reilly. [0045] Enterprise JavaBeans:
Developing Component-Based Distributed Applications, Tom Valesky,
Addison-Wesley. [0046] Enterprise JavaBeans Developer's Guide (Beta
Version) at [0047]
//developer.java.sun.com/developer/earlyAccess/j2sdkee/doc-beta/guides/ej-
b/html/TOC.html [0048] J2EE Application Programming Model (Beta
Release), at
//developer.java.sun.com/developer/earlyAccess/j2sdkee/download-docs.h-
tml all of which are incorporated fully herein by reference. The
system makes use of some third party modules which are described in
more detail below also. The terminology as used and described in
these references for object, class, inheritance, component,
container, bean, JavaBean, EJB, etc., are well known in these arts
and are used herein generally without definition except where a
specific meaning is assigned to a term herein.
Overview of the Platform Architecture
[0049] The following describes an overview of the preferred
embodiment of the SABA architecture, and includes: [0050] A
discussion of the system-level architecture and the modules that
comprise the SABA system. This includes a high-level overview of
each module, and lists the principle interfaces and functionality
defined by each module. [0051] A discussion of the
application-level architecture, covering both the application-level
architecture as exposed to different categories of users and some
of the core business objects and their relationships.
[0052] Referring now to FIG. 5, in the preferred embodiment, Saba's
architecture consists of four layers of APIs: [0053] 1. The
Platform layer 501 provides underlying infrastructure for
enterprise applications, including standards-based functionality
for persistence and distributed logic, application integration,
content generation, and metadata queries. [0054] 2. The Core
Services layer 503 is a module that provides a set of common
functionality for enterprise application. It includes services such
as security, internationalization, and reporting. [0055] 3. The
Common Business Objects layer 505 is a module that defines a set of
business objects shared across all SABA applications. It includes
objects such as Party and Plan. Vertical applications may each also
contribute a set of common business objects. [0056] 4. The
Applications layer 507 provides objects and services particular to
a given application. There are multiple modules contained within
the Applications layer, including modules for Learning 525, Content
527, Performance 529, and Sales & Marketing 531. The specific
applications modules indicated are shown by way of example.
[0057] In the preferred embodiment, applicants have standardized
their APIs around Session Bean Managers, interfaces that expose a
common set of functionality. Each module therefore consists of
several Session Bean interfaces. Thus, while SABA implements its
managers using Entity Beans corresponding to persistent database
objects, the interface as exposed to clients is solely that of the
Managers.
[0058] This architecture also helps avoid circular dependencies by
requiring that all dependencies be directed downwards. That is, a
vertical application 507 may have dependencies on one or more sets
of common business objects 505, but not on other applications.
Similarly, common business objects 505 may depend on core services
503, and on other common business objects 505, but not on
applications 507.
Platform
[0059] The Platform model 501 defines applicants' application
platform, on top of which all additional business logic and
functionality are implemented. Platform 501 provides the full set
of standards-based services required for building modern enterprise
applications.
[0060] Platform 501 consists of the following services: [0061] BDK
(Business Development Kit) Business applications server 519 is
Saba's EJB compatibility layer. It extends the standard Java
business component model with SABA-specific enhancements, such as
improved security and caching, as well as providing an abstraction
layer to improve portability between EJB servers. The BDK 519
defines the following base interfaces: [0062] ISabaEntityBean--The
abstraction of a persistent object [0063] ISabaSessionBean--The
abstraction of a transactional service [0064] WDK (Web Development
Kit) server 523 is Saba's web content generation engine. Using web
standards for XML and XSL, it provides a customizable framework for
decoupling data from presentation, and generating web content in a
variety of formats, from standard HTML to WML. The WDK 523 provides
the following base interfaces: [0065] IWDKObject--An object capable
of serializing itself as XML [0066] Interconnect is Saba's
application integration platform. Using XML and open standards for
ERP integration, it provides a scalable and reliable solution for
batch and period import, export, and monitoring. Interconnect
defines the following base interfaces: [0067] IAccessor--Service
for exporting objects from SABA [0068] IImporter--Service for
importing objects into SABA [0069] IMonitor--Service for monitoring
object changes [0070] Information Distributor Server 521 is
applicants' query and delivery mechanism. Based on XML and RDF
metadata standards, it defines a high-level query language and a
set of agents for implementing information services. Interconnect
provides the following services: [0071] MetadataRepository--A
datastore for querying metadata [0072] ImportAgent--An agent for
generating metadata [0073] MatchAgent--An agent for locating
metadata-based matches [0074] DeliveryAgent--An agent for
delivering match results
[0075] Core Services 503
[0076] The Core Services module 503 provides the common business
services needed by applicants' system. These services are not
specific to any industry, such as learning; instead, they provide
the support and functionality required by applicants to meet
generic enterprise requirements.
[0077] Core Services consist of the following Session Managers:
[0078] AuditManager--Tracks changes to objects in the system. Can
return a complete history of changes, including date, username, and
reason. [0079] BusinessRuleManager--Manage system business rules,
that is, company policies defining the system's behavior in given
situations. [0080] ComponentManager--Manage installed business
objects for naming and instantiation. [0081]
CurrencyManager--Manage currencies and exchange rates. [0082]
DataDictionaryManager--Manage metadata about business objects. This
metadata is used to generate user interfaces, specify constraints,
and define object behavior. [0083] DomainManager--Manage domains.
Domains are hierarchical groupings of business objects that can be
used for a variety of purposes. [0084] FinderManager--Create and
invoke Finders. Finders provide a flexible mechanism for defining
and executing database queries. [0085] HandleManager--Centralize
access to managers available to all business objects. [0086]
i18nManager--Manage internationalization. Track information about
locales, languages, timezones, and display formats associated with
business objects. [0087] LicenseManager--Manage software licensing.
Track installed modules, license keys, and version numbers. [0088]
LOVManager--Define lists of values. [0089]
NLevelHierarchyManager--Support for nested folders. [0090]
FolderManager [0091] FolderElementManager [0092]
NoteManager--Define notes (long text attachments). [0093]
PreferenceManager--Set user preferences. [0094]
SecurityManager--Manage user privileges. Assign permitted
operations on objects to users and groups. [0095]
ServiceHolderManager--Enable and disable common services
(discussion, chat, etc.) [0096] ReportManager--Create and execute
reports. Reporting engines currently supported include Brio and
Crystal Reports 7. [0097] LetterManager--Generate form letters.
[0098] TaxManager--Calculate sales taxes. [0099]
NotificationManager--Manage notifications. Associate actions, such
as sending an email or executing a Java method, with predefined
system and periodic events. [0100] ActionManager [0101]
AttachmentManager [0102] EventManager [0103] ParamManager [0104]
RecepientManager [0105] TextBlockManager [0106] UserManager--Manage
user preferences and allow users to switch between roles.
[0107] Common Business Objects
[0108] The Common Business Objects module 505 defines the set of
business abstractions that are shared across more than one vertical
application. These objects may be either generic business concepts,
such as a Party, or shared concepts specific to Saba's application
domain, such as Calendar.
[0109] Common Business Objects 505 comprise the following Session
Managers: [0110] AccountabilityManager--Used to manage a variety of
relationships, such as reporting and organization membership,
between entities in the system [0111] CalendarManager--Manage
calendars and schedules. [0112] CorporateCalendarManager [0113]
PersonalCalendarManager [0114] SfaCalendarManager [0115]
SfaCalendarOwnerManager [0116] CheckListItemManager [0117]
PartyManager--Manage entities within a business. Includes
employees, clients, companies, departments, and business units.
[0118] LocationManager--Manage locations, including addresses and
contact information. [0119] RoleManager--Manage a function/job type
within the value chain. [0120] PlanManager--Manage plans, that is,
proposed course of actions. [0121] ProfileManager--Manage profiles,
that is, comprehensive histories, goals, and plans for entities
within a business. [0122] ValueChainManager--Manage value chain
relationships between entities in an extended organization.
[0123] Learning
[0124] The exemplary Learning module 525 within the Applications
layer 507 defines the services used to build learning management
systems. It provides APIs for defining learning offerings, which
include classes, courses, on-line learning, and physical inventory,
registering for and consuming learning, and tracking transcripts,
certifications, and other results of learning.
[0125] The following Learning Session Managers are delivered as
part of Common Business Objects 505: [0126] CatalogManager--Browse
a learning catalog. [0127] OfferingTemplateManager--The core
abstraction of a learning intervention.
[0128] The following Learning Session Managers are only available
with the Learning application: [0129] CertificationManager--Track
certifications. [0130] CertificationActionManager [0131]
CertificationCompetencyManager [0132] HeldCertificationManager
[0133] LearningManager--Manage learning offerings. Extends the
concept of offering templates to include managing delivery types
and delivery modes, offering instances, audience types, and
offering modes. [0134] AudienceTypeManager [0135] DeliveryManager
[0136] DeliveryModeManager [0137] EquivalentManager--Defines
equivalent offering templates. [0138] OfferingActionManager [0139]
OfferingManager [0140] OfferingPolicyManager [0141]
OfferingTemplateDeliveryManager [0142] ProductGroupManager [0143]
RosterManager [0144] PrerequisiteManager [0145]
LearningResourceManager--Manage resources used by classes, such as
classrooms, faculty, and equipment. [0146] InventoryManager [0147]
QualifiedInstructorManager [0148] RegistrarManager--Request and
order a learning resource. Includes shipping and registration
information. [0149] CourseRequestManager [0150] PackageOrderManager
[0151] PricingManager [0152] RegistrationManager--Track completion
and grading of learning offerings
[0153] Content
[0154] The Content module 527 within the Applications layer 507
defines the services used for all forms on on-line learning. It
includes creating and launching WBT and VOD courseware, virtual
classrooms, testing and assessment, community services, and
analysis and tracking.
[0155] The following Content Session Manager is delivered as part
of Common Business Objects: [0156] ContentHolderManager--Allows any
business object to be a content holder [0157]
CourseContentManager--Associate content such as attachments and
exams with learning offerings.
[0158] The following Content Session Managers are only available
with the Content application: [0159] ContentManager--Manage
learning content. [0160] TestManager [0161]
AnalysisManager--Analyze test results. [0162]
CommunityManager--Create and manage learning communities.
[0163] Performance
[0164] The Performance module 529 within the Applications layer 507
defines the services available for managing human performance. It
includes competencies and goals.
[0165] The following Performance Session Managers are delivered as
part of Common Business Objects: [0166] CompetencyManager--Assign
competencies to roles, entities, and learning resources. Includes
[0167] CompetencyHolderManager [0168] CompetencyProviderManager
[0169] OfferingCompetencyManager--Associate competencies with
offering templates and find learning interventions that provide
competencies.
[0170] The following Performance Session Managers are only
available with the Performance application: [0171] Advanced
competency definition, manipulation, and analysis, including:
[0172] CompetencyAnalysisManager [0173] CompetencyGroupManager
[0174] CompetencyMethodManager [0175] CompetencyModelManager [0176]
GoalManager--Manage and track goals. Includes assigning goals and
observations on goals. [0177] GoalLibraryManager [0178]
GoalObservationManager [0179] GoalStateManager
[0180] Sales and Marketing
[0181] The Sales and Marketing module 531 within the Applications
layer 507 defines the services available for the running the
finances and logistics of a learning content provider. It includes
the purchase of learning resources and tools for managing sales and
marketing campaigns.
[0182] The following Sales and Marketing Session Managers are
delivered as part of Common Business Objects: [0183]
OrderManager--Generate orders. Includes invoicing and shipping
options. [0184] PurchaseManager--Track the pricing of learning
resources. Includes getting and setting prices and managing price
lists.
[0185] The following Sales and Marketing Session Managers are only
available with the Sales and Marketing application: [0186]
AccountManager--Manage client accounts. [0187] Advanced order
management, including: [0188] TrainingUnitManager [0189]
PurchaseOrderManager [0190] MarketingManager--Manage marketing
campaigns. [0191] RoyaltyInfoManager [0192] ShipperManager [0193]
SalesMktManager--Order a learning resource. Similar functionality
to RegistrarManager, but designed for use in a call center to
fulfill external orders. [0194] TargetMarketManager--Manage target
markets and associate them with offering templates. [0195]
TerritoryManager--Manage territories.
[0196] Applications Architecture
[0197] An exemplary version of an application architecture which
can make use of applicants' invention could consist of four
distinct applications that interoperate to provide a complete Human
Capital Development and Management solution. Each of these
applications is based around a core set of metadata; the
applicants' architecture's value lies in the effective management
of this metadata. The diagram in FIG. 6 describes this core
metadata and how it is employed by different types of users in this
exemplary implementation of this architecture. Those skilled in the
art will recognize that this architecture can be used with various
other kinds of applications systems, such as: financial product
sales & marketing systems; retail store management systems;
various kinds of maintenance & repair management & dispatch
systems; etc.
[0198] Referring now to FIG. 6, SABA Learning manages Catalog
Metadata 609 that describes a set of available learning
interventions and Profile Metadata 611 that describes a learner in
the system, including learning history and enrollments.
[0199] SABA Performance manages Profile Metadata 611 that describes
individual and group goals, competencies, and development plans.
Together, the Profile Metadata 611 in Learning 607 and Performance
605 provide a complete description of the human capital in an
extended organization.
[0200] SABA Information 603 and SABA Content 601 manage metadata
about a variety of on-line resources. SABA Information 603 uses
this metadata to construct information services targeted to
individual's information needs, whereas SABA Content 601 uses this
metadata to manage learning content throughout its lifecycle and
construct intelligent, reusable Learning Objects.
[0201] Users work with this metadata as follows: [0202] Individual
learners 619 query Learning Metadata (that is, the learning
catalog) 609 to locate appropriate learning interventions. The
system uses Learning Object Metadata 613 to deliver and track
learning interventions and updates the Profile Metadata 611 as
appropriate. [0203] Team managers 621 work with Profile Metadata
611 to define, update, and track progress towards goals. They can
analyze the metadata to identify problem areas and generate plans
for meeting their goals. [0204] Learning providers 617 use import
and administration tools to create and update Catalog 609 and
Learning Object Metadata 613.
[0205] One of the principal tasks users perform in such a system is
finding performance interventions--resources and services that can
be applied to improve human capital performance. The diagram in
FIG. 7 details the business objects that support this process and
their relationships.
[0206] There are multiple, complementary mechanisms for identifying
interventions.
[0207] Competency gap analysis can be applied to either an
individual's goals 713 or roles 715. The analysis compares the
required competencies for reaching a goal 713 or filling a role 715
(either held or targeted) to actual held competencies and generates
a competency gap 721. Learning interventions (offerings 723) that
fill the competency gap 721 are the identified. A variety of other
intervention types are planned, including information 733 and
community services 735.
[0208] Certification gap 719 analysis compares a role's
certification requirements associated to the actual learning
profile of the individual in the role. It then identifies the
quickest certification track to completion and recommends
appropriate learning offerings 723 from the catalog.
[0209] Having described an exemplary application we now describe
the invention in additional context.
[0210] In a preferred embodiment, the Platform can support both
Application and Business component development, as well as
integration with development tools, connectivity to external
systems (import/export/exchange), and information delivery. The
architecture of the present invention adopts a three-tier model and
is shown in the diagram in FIG. 3. In FIG. 3 a tier 1 web user 301
is connected electronically to a tier 2 web server 305 which is
connected to a tier 3 applications server 307. Also in Tier 1 a
dedicated user 311 may be directly connected to a tier 3
applications server 307. And the tier 3 applications server 307 may
be connected to a database management system 309.
[0211] Referring now to FIG. 4, the tier 3 applications server 307
is expanded in FIG. 4 to illustrate the Business Applications
Platform 415 of the present invention. In FIG. 4, the Platform
contains an Interface Server 417, an Information Server 419, an
Interconnect Server 423 and a Business Server 421. All of these
Servers 417, 419, 421 and 423 may physically reside on the same
hardware platform (such as a UNIX box or a Microsoft.TM. NT.TM.
platform), or each server may reside on a separate hardware box, or
any combination of servers and hardware boxes. Each of the servers
may have included a JAVA Virtual Machine.TM. and the related
runtime support. The electronic communications between these
servers may use the XML protocol (409, 425, 427) with each server
having services for translating XML into the particular
Applications Programming Interface (API) language required by the
server and for translating its internal language into XML prior to
transmission to another server. In a preferred embodiment, all of
these servers are contained in a single tier 3 platform, and may
communicate with each other directly without the necessity of
changing the interfacing protocol format. The Interface Server 417
(also alternatively designated herein as the WDK), communicates
through a web server 405 via the internet 403 to web clients 401
via the HTML protocol. The Interface Server 417, also may
communicate to a directly connected client 407 via other protocols
such as XSL/XSLT etc., and may communicate to Personal Data
Assistants 411 such as cell phones or Palm Pilots.TM. or other such
wireless devices using wireless protocols such as WAP/WML, etc. The
Interface Server 417, contains mechanisms to manipulate various
kinds of display style sheets, to generate and execute web links,
to manage dynamic content generation and dynamic generation of
Javascript, all of which is described in more detail below in the
section on the Interface Server/WDK 417.
[0212] These servers and related facilities and others are
described in more detail below.
Operating Environment
[0213] The environment in which the present invention is used
encompasses the use of general purpose computers as client or input
machines for use by business users of various kinds, including
clerks, managers, teachers, and/or systems administrators. Such
client or input machines may be coupled to the Internet (sometimes
referred to as the "Web") through telecommunications channels which
may include wireless devices and systems as well.
[0214] Some of the elements of a typical Internet network
configuration are shown in FIG. 1, wherein a number of client
machines 105 possibly in a branch office of a large enterprise, a
manufacturer, a financial enterprise, etc., are shown connected to
a Gateway/hub/tunnel-server/etc. 106 which is itself connected to
the internet 107 via some internet service provider (ISP)
connection 108. Also shown are other possible clients 101, 103
possibly used by other application systems users, or interested
parties, similarly connected to the internet 107 via an ISP
connection 104, with these units communicating to possibly a home
office via an ISP connection 109 to a gateway/tunnel-server 110
which is connected 111 to various enterprise application servers
112, 113, 114 which could be connected through another hub/router
115 to various local clients 116, 117, 118. Any of these servers
112, 113, 114 could function as a server of the present invention,
as more fully described below. Any user situated at any of these
client machines would normally have to be an authorized user of the
system as described more fully below.
[0215] An embodiment of the Business Applications Platform System
of the present invention can operate on a general purpose computer
unit which typically includes generally the elements shown in FIG.
2. The general purpose system 201 includes a motherboard 203 having
thereon an input/output ("I/O") section 205, one or more central
processing units ("CPU") 207, and a memory section 209 which may or
may not have a flash memory card 211 related to it. The I/O section
205 is connected to a keyboard 226, other similar general purpose
computer units 225, 215, a disk storage unit 223 and a CD-ROM drive
unit 217. The CD-ROM drive unit 217 can read a CD-ROM medium 219
which typically contains programs 221 and other data. Such
programmed computers may also be connected electronically to
database systems such as those available from Oracle.TM.,
Sybase.TM., Informix.TM., SQLServer from Microsoft.TM. and the
like. Logic circuits or other components of these programmed
computers will perform series of specifically identified operations
dictated by computer programs as described more fully below.
DETAILED SYSTEM DESCRIPTION
[0216] The Platform system of the present invention is now
described in more detail. In general a preferred embodiment with a
presently known best mode for making and using the system is
described. Alternative embodiments are similarly described for
various parts of the Platform system.
Business Applications Server/BDK
Preferred Embodiment
[0217] The following description of the BDK Business application
server covers the presently preferred embodiment and the presently
known best mode for making and using it. This section is followed
by a further description of an alternative embodiment which may
include features in addition to or in place of those in the
preferred embodiment.
1. Overview
[0218] The Business Development Kit applications server (BDK)
component of the Platform provides a supporting framework for
business objects. A business object is a Java object with
persistent state that represents some entity in a business
application, such as an employee or company.
[0219] Specifically, the BDK provides a persistence framework for
saving and restoring object state and a set of core services for
performing a variety of useful operations on business objects.
2. Persistence Framework
[0220] The persistence framework defines a common code path used to
create new objects, restore and update existing objects, delete
objects, and find objects. The code path consists of a set of Java
code and database stored procedures to construct and verify object
data and SQL commands to save and restore information using a
relational database.
[0221] The persistence framework is highly flexible because it is
metadata-driven. For each class of object, the system provides a
set of metadata--data about data--that defines the class'
properties and behavior. This means that the data used to determine
the behavior and characteristics of specific classes and instances
of business objects is stored as distinct, editable information,
rather than being hard-coded into the logic of the system. The
persistence code itself is part of the metadata, that is, the SQL
commands for save, restore, etc. are stored as metadata, not in
source code. As an example benefit, it makes applications much
easier to port between databases because only the metadata for the
SQL needs to be changed; no source code needs to be changed and
recompiled.
[0222] Use of metadata allows the system to be configured and
otherwise modified by different clients for different deployments,
resulting in unique runtime behavior of the system. Object
properties that can be customized range from the labels used to
display object information, to the type of data validation
performed, to the amount of custom information associated with each
object.
[0223] A unique feature of the persistence framework is its support
for an arbitrary amount of custom information, stored in what is
known as "custom fields." Experience has shown that predefined
business objects typically do not express the full set of data a
given customer may wish to track, and that this data varies from
customer to customer. Custom fields provide a way for different
customers to uniquely extend the data stored with a class of
business objects. In the current implementation, customers are
provided with a set of five "custom fields" that can be searched,
and an unlimited number of "extended custom fields" that cannot be
searched, but provide additional data validation for date and
numeric values. Again, the code to save and restore custom fields
is all driven off metadata.
[0224] As an example of the persistence framework's operation, a
user of the system may attempt to create a new employee by
specifying the employee's first and last name, social security
number, starting salary, and date of birth. The persistence
framework performs the following operations to save this data as a
new "SabaPerson" business object: [0225] Uses metadata settings
about the "first name", "last name", "ssn", and "birth date"
properties of a "SabaPerson" to determine the data validation to
perform. In this case, the metadata settings may instruct the
framework to verify that values are provided for first name, last
name, and ssn, that starting salary is greater than a fixed numeric
minimum wage value, and that birth date is a valid date. [0226]
Uses metadata to obtain and execute a database stored procedure
named "tpp_person_ins" that takes values for first name, last name,
ssn, salary, and birth date as parameters and inserts these values
into a database table named "tpt_person." 2a. The Meta-Data
Store
[0227] In the preferred embodiment the meta-data store contains the
definition of each type of object in the system, its attributes,
and some basic properties of those attributes. Further, for each
type of object, it contains a reference to the methods to invoke,
to insert, update, delete or fetch a given instance of that object
from the persistent store.
The Metadata store consists of the following tables:
TABLE-US-00001 1. fgt_dd_class
[0228] Every business object in the system is registered in this
table. This table also describes basic properties of objects.
[0229] fgt_dd_class has the following columns:
TABLE-US-00002 Column Name Type Rq? Description Id Char(20) The
identifier of the object. Ui_name Varchar2(255) This is the display
name of the object and generally used to paint UI as well.
Description Varchar2(255) Meaningful description of the object and
its function. Enumber int Unique number for each object.
Insert_spid Int Method call for inserting a new instance of the
object. Foreign key to mesg_id column of fgt_mesg_table.
Update_spid Int Method call for updating an existing instance of
the object. Foreign key to mesg_id column of fgt_mesg_table.
Delete_spid Int Method call for deleting an instance of the object.
Foreign key to mesg_id column of fgt_mesg_table. Sel_det_spid Int
Method call for retrieving an instance of the object based on its
id. Foreign key to mesg_id column of fgt_mesg_table. Finder_id Int
Finder Id for invoking a default finder associated with the object.
Fixed_attr_ct Int Total count of the fixed attributes for the
object. Attr_ct Int Total count of the attributes for the object.
This number is sum of all fixed and all custom attributes. Flags
Char(10) Ten bit string describes the behavior of the object. 1st
bit = Object can be displayed in the security screen for granting
privs. 2nd bit = This 2bit mask is set to see if reports or letters
or both can be attached. 3.sup.rd bit = Obsolete. 4.sup.th bit =
Obsolete. 5.sup.th bit = If the object is owned in nature and
cannot exist without its owner. 6.sup.th bit = Obsolete 7.sup.th
bit = If object can be customized bu end user. 8.sup.th bit = If
Object can have Extensible attributes of its own. next_attr_enum
Int Enumber to use for the next custom attribute that will be added
to the object. The install time value for this attribute is 10,000.
Prefix char(5) This 5letter long string is used in generating Ids
for the object. This string is prepended to the number generated by
the sequence. Table_name Varchar2(25) This is the name where the
object is stored. The sequence, methods are also named based on
this. Domain_enum Int This is denormalized data and shows the
enumber of the Domain attribute. Java_class_name Varchar2(255) The
java class name of the object. Hlevel Int The level of the object
in the object hierarchy. Parent_id Char(20) In case of hierarchical
object's it stores the parent object's Id
[0230] As an example, the following are the values for a class of
business object representing domains:
TABLE-US-00003 descrip- Id ui_name tion enumber insert_spid
ddcls000000000001095 Domain Hier- 195 10560 archal Domain
TABLE-US-00004 update_spid delete_spid sel_det_spid finder_id
fixed_attr_ct 10562 10561 10563 15710 14
TABLE-US-00005 attr_ct flags next_attr_enum prefix table_name 14
1100001100 100000 domin fgt_domain
TABLE-US-00006 domain enum java_class_name hlevel parent_id
com.saba.busobj.SabaDomain 1
TABLE-US-00007 2. fgt_dd_attr
[0231] The attributes of each class of business object is stored in
this table. This table also describes basic properties of each
attribute.
[0232] fgt_dd_attr has the following columns:
TABLE-US-00008 Column Name Type Rq? Description Id Char(20) Y
Unique identifier for an attribute. Cid OBJECTID Y The object Id,
this attribute belongs to Enumber Int Y Required to be unique
within a class. The code should use these numbers to refer to
attributes rather than using the ID. Fixed enumbers are assigned in
the range 1000-9999. Extensible attributes are allocated from
10,000 onwards. The next_attr_enum in the corresponding object
record stores the next enumber available for this class. Col_name
Varchar(255) Y The column name in which the value of this attribute
is stored. Ui_name Varchar(255) Y The name of the attribute, which
is used for painting the UI. description Varchar(255) N Description
of the attribute. Attr_type Int Y The number corresponds to the
data type of the attribute. list_of_vals OBJECTID N If the
attribute val. is selected from a list of values, then the id of
the list is stored here. min_val Int N If its a numeric column,
then the min allowable value if any. max_val Int N If its a numeric
column, then the max allowable value if any. default_val STR N
Default value to use for the attribute when an instance of the
object is created. str_1 STR N This generation formula for those
attributes whose values have to be generated on the creation of the
object. The generation is driven by the generation bit in the flag.
Flags varchar(15) Y 1.sup.st bit => The required bit. 2.sup.nd
bit => Reference bit is set if attribute points to another
object. 3.sup.rd bit => LOV bit is set if its values must come
from fixed list of values. 4th bit => This two bit mask
describes the type of the attribute. 5th bit => Id bit is set if
its an Id column. 6th bit => Generation bit is set if the value
need to be generated during the creation of an object. 7th bit
=> Customization bit. This 4bit mask says if label, required or
generation can be customized by end user. 8th bit => Audit bit.
9th bit => Obsolete 10th bit => Obsolete 11.sup.th bit =>
This bit describes the type of the custom attribute. 12.sup.th bit
=> Domain bit is set if the attribute is domain id. 13.sup.th
bit => set if Default value can be changed by user. 14.sup.th
bit => set if Minimum value can be changed by user. 15.sup.th
bit => set if Maximum value can be changed by user.
[0233] As an example, the following are some of the attributes
defined for the domain business object:
TABLE-US-00009 id cid enumber col_name ui_name attr_type flags
ddatr000000000002991 ddcls000000000001095 1000 id ID 8
100011000000000 ddatr000000000002992 ddcls000000000001095 1001
time_stamp Time 4 100000000000000 Stamp ddatr000000000002993
ddcls000000000001095 1002 name Domain 4 100000100000100 Name
ddatr000000000002994 ddcls000000000001095 1003 description
Description 7 000000300000100 ddatr000000000002995
ddcls000000000001095 1004 custom0 custom0 7 000100300010100
TABLE-US-00010 3. fgt_mesg_table
[0234] This table stores the actual SQL code used for object
persistence. In the case of insert, update, and delete methods,
typically these are calls to stored procedures containing
additional business logic in addition to database calls.
[0235] Long SQL statements are stored in multiple rows, which are
then reconstructed on-the-fly by the persistence layer.
[0236] fgt_mesg_table has the following columns:
TABLE-US-00011 Column Name Type Rq? Description Mesg_id Int Y This
is the message id for the SQL statement group. Mesg_seq Int Y Since
the SQL statements can be greater than 255 chars which is the
length of the mesg_text columns. This column tells the sequence of
this SQL statement in the group. Mesg_text Varchar(255) Y The text
of message.
[0237] As an example, the following are persistence calls for the
domain business object. Note from the sample data above that 10563
is the code for retrieving an object, 10560 for inserting an
object, and 10562 for updating an object.
TABLE-US-00012 mesg_id mesg_seq mesg_text 10563 1 select d.id id,
d.time_stamp ts, d.name dname, d.description descr, d.custom0 c0,
d.custom1 c1, d.custom2 c2, d.custom3 c3, d.custom4 c4,
d.created_on cron, d.created_by crby, d.updated_on upon, d.upd
10563 2 ated_by upby, d.parent_id pid, parent.name parent from
fgt_domain d, fgt_domain parent where d.id = @001 and d.parent_id =
parent.id(+) 10560 1 begin fgp_domain_ins (@001, @002, @003, @004,
@005, @006, @007, @008, @009, @010, @011, @012, @013, @014, @015);
end; 10562 1 begin fgp_domain_upd (@001, @002, @003, @004, @005,
@006, @007, @008, @009, @010, @011, @012, @013, @014, @015);
end;
[0238] Notice that the SQL references the actual table used to
store domain data, fgt_domain (described in detail in the section
on security).
[0239] The fgp_domain_ins stored procedure is PL/SQL code defined
as:
TABLE-US-00013 create or replace procedure fgp_domain_ins ( xid
char, xtime_stamp varchar2, xname varchar2, xdescription varchar2,
xcustom0 varchar2, xcustom1 varchar2, xcustom2 varchar2, xcustom3
varchar2, xcustom4 varchar2, xcreated_on date, xcreated_by
varchar2, xupdated_on date, xupdated_by varchar2, xparent_id char,
xnewts varchar2 ) as begin /* validating that the parent of a node
is not itself */ if (xid = xparent_id) then
raise_application_error(-20698, ``); return; end if; /* parent_id
cannot be null except for the root */ if (xid <>
`domin000000000000001` and xparent_id is null) then
raise_application_error(-20699, ``); return; end if; insert into
fgt_domain ( id, time_stamp, name, ci_name, description, custom0,
custom1, custom2, custom3, custom4, created_on, created_by,
updated_on, updated_by, parent_id) values ( xid, xnewts, xname,
lower(xname), xdescription, xcustom0, xcustom1, xcustom2, xcustom3,
xcustom4, sysdate, xcreated_by, sysdate, xupdated_by, xparent_id);
/* update the denormalized flat tree table */
tpp_flat_tree_relation(195, xid, null, null, 0); /* inherit a
snapshot of the custom fields for all objects */ insert into
fgt_dd_domain_to_attr (ID, TIME_STAMP, DOMAIN_ID, ATTR_ID, FLAGS,
LOCAL_FLAGS, UI_NAME, MIN_VAL, MAX_VAL, DEFAULT_VAL, LIST_OF_VALS,
GEN_MASK) select `ddoat` ||
lpad(ltrim(rtrim(to_char(fgt_dd_domain_to_attr_seq.nextval))), 15,
`0`), xnewts, xid, ATTR_ID, FLAGS, LOCAL_FLAGS, UI_NAME, MIN_VAL,
MAX_VAL, DEFAULT_VAL, LIST_OF_VALS, GEN_MASK from
fgt_dd_domain_to_attr where domain_id = xparent_id; end;
2b. Persistence Algorithms
[0240] In a preferred embodiment all business objects that Saba's
Application server manipulates are derived from a single base class
called SabaObject. The SabaObject class provides save, restore, and
delete capabilities by implementing the persistence layer
architecture. All subclasses of SabaObject then inherit this
behavior and rarely if ever override it. [0241] Every SabaObject is
expected to know which class it belongs to, and how that class is
registered in the meta-data store. Thus each subclass of SabaObject
stores a class identifier so that it can tell the system which
entry in the meta-data store it corresponds to. [0242] Every
SabaObject also stores a state flag that determines whether this is
a new object, or it is an object that already exists in the data
store. This state then determines whether the object invokes an
insert method or an update method during a save( ) invocation.
[0243] Every SabaObject has an unchangeable, unique identifier that
identifies that particular object in the persistence store. The
uniqueness of this identifier is guaranteed across the entire
persistence store regardless of the type of object.
[0244] The algorithm for save is then as follows: [0245] Look up
the entry for the class of the object in the meta-data store.
[0246] If the class is not found, raise an error "Unknown Class".
[0247] If (State=new) [0248] M=look up the method to call for
inserting the object.
[0249] Else/* State=update */ [0250] M=look up the method to call
for updating the object [0251] Marshall all the attributes of the
SabaObject into the appropriate data structure. [0252] Check each
of the attributes against the rules set for its nullity,
constraints. If any of the constraints are violated, throw an
error. [0253] Lead the default values wherever necessary. [0254]
Invoke M with that data structure. (1)
[0255] For deletion, the basic process is identical, except that
the invocation of the delete method only requires the unique
identifier of the SabaObject to be passed in as its only
argument.
[0256] For restore, the algorithm is just slightly different and is
as follows: [0257] Look up the entry for the class of the object in
the meta-data store. [0258] If the class is not found, raise an
error "Unknown Class".
[0259] M=look up the method to call for fetching the object.
[0260] Invoke M(unique ID of SabaObject) [0261] Unmarshall all the
attributes returned by M. (2)
[0262] In the presently preferred embodiment, the method invocation
currently only supports invocation of database stored procedures
although in alternative embodiments this will be extended to other
types of persistence mechanisms.
[0263] These stored procedures provide the actual intelligence of
taking the marshaled arguments that come in, and storing them in
specific fields in the database, and vice versa. Thus a combination
of the meta-data store and the stored procedures create an
abstraction layer that allows the base SabaObject to store all
objects through a simple, uniform algorithm, such as illustrated in
FIG. 18.
[0264] The persistence mechanism thus created, allows the transfer
of various kinds of objects to database storage as shown in FIG.
19.
[0265] Individual messages are retrieved using a SQL command of the
form:
TABLE-US-00014 select mesg_id, mesg_seq, mesg_text from
fgt_mesg_table where mesg_id = ? order by mesg_id, mesg_seq
[0266] Query results are transformed into actual SQL code using the
following method:
TABLE-US-00015 private static String processMessage(ResultSet rSet)
throws Exception, SabaException { StringBuffer buf; String str; buf
= new StringBuffer(rSet.getString(kMsgTextCol)); while (rSet.next(
) != false) { String temp = rSet.getString(kMsgTextCol);
buf.append(temp); } str = buf.toString( ); return str; } }
[0267] Retrieved messages are also stored in a local cache for
improved performance.
2c. Configurable Custom Fields
[0268] In the preferred embodiment, the Saba persistence mechanism
provides built-in support for configurable, runtime definable,
custom fields for any object.
[0269] The basic mechanism is extremely simple. An administrative
user interface is provided by which the meta-data definition of a
given class can be extended by adding (or removing) custom
attributes as needed. For each custom attribute, the user only
needs to provide some very basic information about the type of the
field, whether or not it is required, constraining minimum and
maximum values for numeric fields, and a constraining list if the
field is to be validated against a list of possible values.
[0270] The SabaObject implementation then simply picks up these
fields during its normal marshalling and unmarshalling of
arguments. Further, the SabaObject also performs the basic checks
for nullity as it would normally do.
[0271] To save and restore the custom fields, the actual algorithms
are extended from the ones shown earlier. In the case of insert or
update the following additional lines are called after the line
marked (1) in the algorithm shown earlier: [0272] After invoking
the basic method M [0273] Marshall all custom field data into the
appropriate data structure [0274] Invoke the insert/update method
for storing the custom data structure.
[0275] In the case of restore, the following lines are added to the
original algorithm after the line marked (2): [0276] Invoke the
custom field fetch [0277] Unmarshall all custom field data and
update the relevant fields in the SabaObject.
[0278] The actual storage where the custom field data for any given
instance is stored, consists of a single table as defined below.
All the custom field data is stored as tag-value pairs in typed
columns.
[0279] Fgt_dd_custom
[0280] This common table provides the storage area for all data
stored in the extended custom fields for a given object.
TABLE-US-00016 Column Name Type Rq? Description Id OBJECTID Y
owner_id OBJECTID Y Which object this custom field is for. attr_id
OBJECTID Y Refer to the attribute for which value is stored.
attr_type INT Y Type of the custom field. This matches the
attr_type in the fgt_dd_attr table and is a denormalization of the
same. Num_value Number N Value is stored here if it is Numeric type
Str_value Varchar(255) N Value is stored here if it is String type
Date_value Date N Value is stored here if it is Date type
3 Core Services
[0281] BDK also provides a set of core services to perform useful
operations on business objects. Some of these services include:
[0282] Security. BDK provides extremely fine-grained security
control to control whether specific users have privileges to
perform operations such as creating or viewing a particular class
of business object. The system is unique in that it provides a
flexible model of security roles and security lists to assign a set
of privileges to distinct groups of users, and it employs a
scalable notion of domains to differentiate among sets of business
objects. The security model is explained in detail in a separate
section below. [0283] Auditing. BDK provides the ability to track
the history of all changes to an object, including the date of a
change, the identity of the user making the change, and a
justification for the change. [0284] Internationalization (i18n).
BDK provides utilities for allowing business objects to be
internationalized. Internationalization is a standardized process
wherein message content, money amounts, dates and various other
culture specific data are kept in separate files in order to permit
an easy change from one countries language and cultural rules to
another. This comprises both storing values of business objects in
multiple languages and supporting multiple formats for date,
currency, and other data types that vary among countries. [0285]
Concurrency. BDK provides concurrency services for controlling
overlapping write operations on multiple instances of an object,
while permitting multiple reads at the same time. This is achieved
via comparison of an instance-specific timestamp when committing of
an object's state to the persistent store is requested. The
timestamp is updated whenever the state of an object is altered and
the object is successfully committed to persistent storage. [0286]
Transaction Management. BDK provides two types of transactional
services: procedural and declarative. In the former case, a
developer explicitly marks the beginning and end of a unit-of-work
using BDK's API. In the latter case, a developer can associate a
transactional attribute with a method, and the BDK's Transaction
Monitor keeps track of initiating and terminating transactions, as
well as executing a method within the scope of an on-going
transaction, based on run-time context. [0287] Logging. BDK
provides logging functionality that can be used for capturing
system state and operations in one or more logs. [0288]
Notification. BDK provides the ability to send notifications, such
as emails or faxes, to predefined categories of users when the
state of identified business objects changes. For example, everyone
subscribed to a class may receive a page if the class is cancelled.
[0289] Business Rules. In a preferred embodiment, for example,
Saba's learning application provides a set of pre-defined business
rules that affect the workflow and behavior of various business
objects in the system. The BDK provides a mechanism to enable and
disable these business rules. For example, a customer can configure
whether a manager's approval is required to register for a class.
Similar business rules can be handled for other types of
applications. [0290] Notes. BDK provides the ability to associate
arbitrary, free-form text, or "notes," with any business object in
the system.
4 Application Programming Interfaces
[0291] In the preferred embodiment, the BDK exposes Application
Programming Interfaces (APIs) for use in programming the system. A
variety of APIs with equivalent functionality are supported on top
of the persistence framework. The system supports both propriety
and industry-standard forms of Java API, as well as XML-based
APIs.
a. SabaObject API
[0292] One Java API is a proprietary "SabaObject" interface to a
business object. A SabaObject is a Java class defining a set of
operations common to all business objects, including the ability to
get and set properties using a variety of data types and the
ability to save and restore an object's state. Specific business
object classes can subclass SabaObject to add functionality and
business logic appropriate to that class.
[0293] The Java interface for SabaObject is the following:
TABLE-US-00017 public class SabaObject { /** * SabaObject
Constructor * Creates a new empty Saba object in the context of the
given session. */ public SabaObject(String sessionKey); /* methods
to set attribute values as different datatypes */ public void
setAttrVal(String attrName, Boolean attrVal); public void
setAttrVal(String attrName, Timestamp attrVal); public void
setAttrVal(String attrName, Integer attrVal); public void
setAttrVal(String attrName, BigDecimal attrVal); public void
setAttrVal(String attrName, String attrVal); public void
setAttrVal(String attrName, Object attrVal); /* methods to restore
attribute values as different datatypes */ public String
getAttrVal(String attrName); public String getStringAttrVal(String
attrName); public Integer getIntegerAttrVal(String attrName);
public Timestamp getTimestampAttrVal(String attrName); public
BigDecimal getBigDecimalAttrVal(String attrName); public Boolean
getBooleanAttrVal(String attrName); /** * Gets a hashtable of the
attribute values. */ public Hashtable getAttributeValues( ); /** *
Returns the display label for the named attribute */ public String
getAttributeLabel( String attrName); /* save, restore, and delete
methods */ public void save( ); public void save(SabaTransaction
tr); public void restore( ); public void restore(SabaTransaction
tr); public void delete( ); }
[0294] In the preferred embodiment, as part of a business object's
creation, the business object author provides four SQL statements
corresponding to selection, deletion, insertion, and updating of
the object. Pointers to these statements are provided as part of
the metadata for the object as stored in fgt_dd_class. The first
two (selection and deletion) types of statements take a single bind
variable, namely, the id of the object. The other two take the id
as well as all other attribute values in the order declared in the
metadata for that object's attributes in the table fgt_dd_attr. The
order of retrieval of attributes in the selection statement must
also match such order.
[0295] Upon receiving a request to create an in-memory
representation of an object through the "restore( )" method, BDK
retrieves the selection statement for that class of objects, binds
the variable to the id of the object that is desired to be
restored, executes the statement, and fills in an instance-specific
hashtable of attribute-value pairs with the values so retrieved. In
addition, a standard SQL statement is executed to retrieve the
value of extended custom attributes, and the results are again
inserted in the aforementioned hashtable. For the
"restore(SabaTransaction tr)" variant of this operation, the
execution of these SQL statements is done using the database
connection contained in tr, the transaction argument. When
executing the "delete( )" method, the object is marked for
deletion. Upon a subsequent call to "save( )" or
"save(SabaTransaction tr)," BDK checks for the state of the object.
If it is an object that has been marked for deletion, the deletion
SQL statement as supplied by the business object author is executed
after binding the id, using the database connection in the
transaction argument for the "save(SabaTransaction tr)" case. Other
possibilities upon execution of the save operation are that the
object instance is new, or it is an altered state of an existing
object. In these cases, the statements corresponding to insertion
and updating are executed, respectively, after the replacing the
bind variables with attribute values from the hashtable in the
order specified in metadata. In the case of insertion, BDK
automatically generates a unique id for the object that is
reflected both in the persistent storage and the in-memory
representation.
[0296] Implementation of the setAttrVal( ) and
get<type>AttrVal( ) involve setting and accessing values in
the hashtable, respectively, using the provided attribute name as
the key. getAttributeValues( ) returns a copy of the object's
hashtable whereas getAttributeLabel( ) looks up the attributes'
metadata and returns the label corresponding to the chosen
attribute.
4b. SabaEntityBean API
[0297] Another Java API is based on the industry-standard
Enterprise JavaBean (EJB) model. This model has a notion of "entity
beans" that provide the interface to specific business objects.
Accordingly, the persistence framework provides a EJB-based
abstract class, "SabaEntityBean" that implements the
javax.ejb.EntityBean interface. The SabaEntityBean class provides
default implementations of the following methods: ejbActivate( ),
ejbPassivate( ), ejbRemove( ), setEntityContext( ), ejbCreate( ),
ejbLoad( ), ejbStore( ), and unsetEntityContext( ). Implementations
of the ejbLoad( ), ejbStore( ), ejbCreate, and ejbRemove( ) methods
rely on the selection, update, insertion, and deletion statements
declared as part of metadata (please refer to the discussion of the
implementation of SabaObject's API). Other methods are implemented
as empty stubs that can be overridden by a developer if
desired.
[0298] In addition to defining the bean class, to implement an EJB
one also needs to define a corresponding remote interface, a home
interface, and, for entity beans, a primary key class. The remote
interface is the external world's view of the bean and is comprised
of the business methods that the bean wishes to expose. The getters
and setters for the bean's attributes are also exposed through the
remote interface. The home interface declares the life-cycle
methods, such as those for creating, removing, or finding
beans.
[0299] In the preferred embodiment, the BDK provides two
interfaces, ISabaRemote and ISabaHome, which a bean can extend for
defining remote and home interfaces, respectively. The ISabaRemote
interface extends the standard EJB interface EJBObject and provides
the following sets of methods: [0300] void setCustomAttrVal(String
attr, <type> value), and [0301] <type>
getCustomAttrVal(String attr) for Boolean, Timestamp, String,
Integer, Float, and Double data types. The ISabaHome interface
provides a layer of abstraction over the standard EJB interface
EJBHome. The BDK also defines a class SabaPrimaryKey (a thin
wrapper around the String class) which can be used by entity beans
for defining primary keys. 4c. Session Manager APIs
[0302] The EJB model also has a notion of "session beans,"
higher-level interfaces that represent business processes. In the
preferred embodiment, the BDK has standardized on the use of
session bean-based interfaces as its public API; these interfaces
are known as "session bean managers," and are implemented using the
lower-level entity bean APIs provided by the persistence layer. The
BDK provides a SabaSessionBean base class that defines common
session bean manager functionality, and a framework for several
categories of "helper classes"--additional interfaces used in
conjunction with specific session bean managers: [0303]
Detail--represent immutable detail information about a specific
business object [0304] Handle--represent opaque references to a
business object [0305] Primitive--represent commonly used data
structures, such as addresses and full names 4d. XML Interfaces
[0306] In the preferred embodiment, the BDK also provides XML-based
interfaces for saving and retrieving business objects; these
interfaces provide the communication layer with the other Platform
servers and components.
[0307] One XML format is known as "Saba Canonical Format" (SCF). It
is an XML serialization of the data in a SabaObject. The
Interconnect server system reads and writes SCF to implement the
AccessorReader and ImporterWriter for the native Saba system; refer
to the Interconnect server section for more details.
[0308] An example fragment of an SCF document, representing a
business object defining a specific currency, is:
TABLE-US-00018 <SabaObject type="com.saba.busobj.SabaCurrency"
id="crncy000000000000001" status="existing"> <name
dt:type="string">US Dollars</name> <time_stamp
dt:type="string">199812161647032900</time_stamp>
<short_name dt:type="string">USD</short_name> <flags
dt:type="string">1100000000</flags>
</SabaObject>
[0309] In the preferred embodiment, another XML interface is the
"IXMLObject" interface. An IXMLObject is a Java object capable of
serializing itself into an XML representation. The detail, handle,
and primitive helper objects used by session bean managers all
implement this interface. The WDK server system uses these objects
to generate dynamic web content by invoking the session bean
manager APIs, then serializing the resulting objects into XML;
refer to the WDK section for more details.
[0310] The IXMLObject interface conforms to the "Visitor" design
pattern, and is defined as follows:
TABLE-US-00019 public interface IXMLObject { /** * Accept a
visitor. An implementation should ask the Visitor to visit each of
its public elements (i.e., fields or properties). * * @param
visitor The XML Visitor object */ public void
acceptXMLVisitor(IXMLVisitor visitor) throws XMLVisitorException;
/** * Get the preferred tag name for this object. * @return the tag
name to identify */ public String getTagName( ); }
[0311] Note: a "visitor" object is one which has processes which
represent an operation to be performed on the elements of an object
structure. A visitor lets one define a new operation without
changing the classes of the elements on which it operates. Visitor
objects and their operation and use are described in more detail at
pages 331-344 of Design Patterns, by Gamma, Helm, Johnson, &
Vlissides, Addison-Wesley 1995, ISBN 0-201-63361-2 which are hereby
fully incorporated herein by reference. Those skilled in these arts
will recognize that various other implementations of these
algorithms and concepts may be developed without departing from the
spirit and functionality of this invention. Additional background
information can be found in
[0312] Enterprise JavaBeans Specification, v1.1 (can be found at
url=java.sun.com/products/ejb/docs.html), and in other sections of
the book titled
[0313] Design Patterns, by Gamma, Helm, Johnson, & Vlissides,
Addison-Wesley 1995, ISBN 0-201-63361-2 which are hereby fully
incorporated herein by reference.
ALTERNATIVE EMBODIMENT
[0314] An alternative embodiment of the BDK business applications
server may be described as follows, using the context of how a
developer and user would use this portion of the system. In an
alternative embodiment, the developer's use is outlined in the
context of a BDK development kit which would be provided by
Applicants for use in developing applications which can run on the
Platform and by way of indicating some details unique to the
Platform through a description of a use of the Business Development
Kit.
[0315] In the alternative embodiment, the Business Server embodies
a development kit framework which provides a set of interfaces and
classes in the form of Java packages, identifies certain services
that developers can rely on, and defines an application development
model. The framework relies extensively on the server-side
component model espoused by Java, namely Enterprise JavaBeans (EJB)
components. Selection of EJBs as the server-side component model is
driven in part by the requirements of reliance on open standards
and backward compatibility. Using EJBs also enables integration
with other Java 2 Enterprise Edition (J2EE) technologies such as
Java ServerPages (JSP) and servlets that one would intend to use
for web applications development. Furthermore, a number of
EJB-enabled application servers available in the marketplace could
be used to deploy the components so developed.
[0316] In the alternative embodiment, the development kit classes
and interfaces, the services, and the application development model
are discussed in greater detail in the next three subsections.
Classes and Interfaces
[0317] The BDK interfaces and classes address the following needs.
[0318] 1. Provide an additional layer of abstraction (by writing
wrappers around base Java classes) to provide a richer level of
functionality needed by SABA applications and to allow future
modifications with minimal impact on the client application code.
[0319] 2. Expedite component development by providing default
implementations (that can be overridden) of certain required
interfaces in EJB. [0320] 3. Define certain interfaces that must be
implemented by classes used for specific purposes (an example is
that a class must implement a certain interface if its instances
are used in a JSP page). [0321] 4. Define certain classes that are
necessary to provide basic services, such as data partitioning and
logging, as well as utility classes for expedited application
development. [0322] 5. To the extent possible, eliminate
application server dependencies in areas where the EJB
Specification is currently not vendor independent.
[0323] In the alternative embodiment, the following discussion of
is background for a discussion of the usage and types of EJBs
within the context of the development kit described in more detail
below.
Metadata Support
[0324] In the alternative embodiment, one of the facilities
provided by the development framework is that characteristics of
business objects can be varied across deployment. For example, for
an attribute, one can optionally specify whether it has a required
attribute, the list of values (LOVs) that the attribute can assume,
its default value, and its minimum and maximum values. The values
can be different across installations, as different customers have
different requirements. To achieve this flexibility, metadata about
the business objects and their attributes is captured in the
system.
[0325] In the alternative embodiment, some of the metadata that is
currently captured about a class or an attribute could be
dynamically determined using the Java reflection API. Examples
include the parent ID and attribute count for business objects and
attribute type for an attribute. The Java reflection API provides
classes Class and Field that can be used to retrieve such
information. Furthermore, instead of building a hashtable-based
infrastructure for storing and retrieving attribute values, one can
use methods like set and get in the Field class to operate directly
on the attributes, which are declared as member variables of the
class.
[0326] The classes Class and Field by themselves, however, may not
provide the rich functionality needed by certain applications. For
instance, there is no way to indicate minimum and maximum values of
an attribute in the Field class. Thus, what is needed is to create
new classes that provide wrappers around Class and Field and
capture the additional information. In the interest of consistency
with previously used names while avoiding conflicts at the same
time, two new classes may be used: SabaPlatformClass (inherits from
Class) and SabaPlatformAttribute (inherits from Field). In addition
to the functionality provided by Class (e.g., for getting parent
class), SabaPlatformClass provides for such additional
functionality as domain-based attributes and getting fixed vs.
extended custom attribute counts. Similarly, SabaPlatformAttribute
provides functionality for LOVs, default value, and minimum and
maximum values. (As we will discuss later, the classes
SabaPlatformClass and SabaPlatformAttribute themselves are
beans--or, entity beans to be more specific-in this alternative
embodiment system.)
[0327] The classes SabaPlatformClass and SabaPlatformAttribute will
not be used directly by users of business components (though
developers of such components will use them). Typically, the user
of these classes will be a class SabaPlatformObject. In some
instances, SabaPlatformObject will make use of the functionality
provided by these classes as part of an operation (e.g., when
setting the value of an attribute, SabaPlatformObject will use
SabaPlatformAttribute to determine the minimum and maximum value
constraints). In other cases, SabaPlatformObject will delegate an
operation directly to one of these classes (an example would be
retrieving the superclass of an object). SabaPlatformObject
implements a set of methods for getting and setting attribute
values that provide a centralized point for capturing the logic for
such things as auditing and constraint checking, and are used by
subclasses of SabaPlatformObject.
[0328] In this alternative embodiment, a component user will not
interact directly with even SabaPlatformObject. Instead, the
component user will deal with a specialization of either a
SabaEntityBean or a SabaSessionBean, which are discussed in the
next subsection.
Beans
[0329] In the alternative embodiment, components based on
Enterprise JavaBeans (EJBs) will be a basic building block for
developing applications using the BDK. Below we provide a brief
overview of EJBs. Those skilled in these arts will understand that
various books and documents on the "java.sun.com" web site provide
additional details on this subject. There are two types of
EJBs:
[0330] 1. Entity Beans, and
[0331] 2. Session Beans.
[0332] Entity beans are used for modeling business data and
behavior whereas session beans are used for modeling business
processes. Examples of entity beans could be SabaClass (a training
class, not a Java class), SabaPerson, and SabaRegistration. Entity
beans typically would map to objects (tables) in the persistent
data store. Behaviors associated with an entity bean typically
would relate to changing the data in the bean.
[0333] An example of a session bean could be SabaRegistrar, which
uses the entity beans mentioned above and encapsulates the business
logic associated with certain tasks, such as registering for a
class. Session beans are not persistent, though changes in data of
certain entity beans or their creation or removal could result from
the actions of a session bean. A session bean can be stateful or
stateless. A stateful session bean maintains state information
specific to the client using it, such that results of invocation of
a method may depend upon the methods invoked earlier on the bean.
(An example of a stateful session bean would be SabaShoppingCart,
which would keep track of items in an order as they are being
added, to be followed by either placement of the order or clearing
of the cart.) This is typically done by storing client-specific
data in instance variables of a bean, which are then used by the
methods to accomplish their task. A stateless session bean does not
maintain any state specific to a client. An example of a stateless
session bean would be SabaTaxCalculator, which provides methods for
computation of sales and other taxes.
[0334] In the alternative embodiment the development kit would
provide two abstract base classes: SabaEntityBean and
SabaSessionBean. (Whether a session bean is stateful or stateless
is indicated in something called a deployment descriptor.) These
classes implement the javax.ejb.EntityBean and
javax.ejb.SessionBean interfaces, respectively. The intent is to
provide a default implementation of certain required methods to
enable rapid development of components, yet allow a component to
override the default implementation of the methods it chooses. The
SabaEntityBean class provides default implementations of the
following methods: ejbActivate( ), ejbPassivate( ), ejbRemove( ),
setEntityContext( ), ejbCreate( ), ejbLoad( ), ejbStore( ), and
unsetEntityContext( ). Implementation of the ejbRemove( ) and
ejbCreate( ) are discussed in the next subsection. The other
methods in the list by default have an empty implementation. The
SabaSessionBean class provides default (empty) implementations of
the first four methods in the preceding list.SabaEntityBean
inherits from SabaPlatformObject and provides attributes common to
all the entity beans, (such as namespace) and has a method toXML( )
that ensures that all entity beans will provide an implementation
for serializing their data to an XML representation. In other
words, SabaEntityBean implements an interface ISabaXMLRenderable
(explained later) and provides two convenience methods:
findUsingRQL(String rql) and findUsingRQLURI (String URI) to locate
specific entity beans using RQL.
[0335] In addition to defining the bean class, to implement an EJB
one also needs to define a corresponding remote interface, a home
interface, and, for entity beans, a primary key class. The remote
interface is the external world's view of the bean and is comprised
of the business methods that the bean wishes to expose. The getters
and setters for the bean's attributes are also exposed through the
remote interface. A developer must implement these methods by
calling the getAttrVal( ) and setAttrVal( ) methods available in
SabaPlatformObject to take advantage of services like constraint
checking and auditing. The home interface declares the life-cycle
methods, such as those for creating, removing, or finding
beans.
[0336] The development kit provides two interfaces ISabaRemote and
ISabaHome, which a bean can extend for defining remote and home
interfaces, respectively. The ISabaRemote interface extends the
standard EJB interface EJBObject and provides the following sets of
methods: [0337] void setCustomAttrVal(String attr, <type>
value), and [0338] <type> getCustomAttrVal(String attr)
[0339] for Boolean, Timestamp, String, Integer, Float, and Double
data types. The ISabaHome interface provides a layer of abstraction
over the standard EJB interface EJBHome. The BDK also defines a
class SabaPrimaryKey (a thin wrapper around the String class) which
can be used by entity beans for defining primary keys.
[0340] One final interface defined in the BDK for EJBs is
ISabaXMLRenderable. This interface extends the java.io.Serializable
interface and defines a single method, tOXML( ). Only classes that
implement this interface are eligible to act as return types of
methods that are going to be invoked from a Java ServerPage.
[0341] In the alternative embodiment the BDK would come with a few
prepackaged beans. One is a stateless session bean named
SabaPlatformLogin that can be used to authenticate a user. Another
is an entity bean named SabaNameSpace, which encapsulates
characteristics of a namespace, including its place in the
hierarchy and the list of users who have access to entity beans in
that namespace. The namespace is used for data partitioning and
security purposes.
Relationships
[0342] Another area in which the BDK provides support is
relationships amongst entity beans. In an object model,
relationships between different classes are arranged in four
categories: inheritance, association, composition, and aggregation.
During implementation, the inheritance relationship is captured by
extending a subclass from a superclass. The other three types of
relationships entail constraints between the classes being related.
For instance, a composition relationship implies commonality of
life span (i.e., destroying the "whole" should result in
destruction of the "components") and an association relationship
implies referential integrity constraints (i.e., creating an
instance of a class which refers to a non-existent interface of
another class is not permitted). In an alternative embodiment, such
relationships can be captured through constraints in the
database.
[0343] In the alternative embodiment, the BDK will provide a
SabaRelationship class, that has attributes for the name of
relationship, the type of relationship, the source class and
attribute, and the destination class and attribute. The
SabaRelationship class will encapsulate lifetime management
constraints implicit in each of the different types of
relationships. Thus, if an object is being removed and it is
declared to have compositional relationship with some other
objects, the SabaRelationship class will ensure the removal of the
related objects. Similarly, when creating an object, the
SabaRelationship class will ensure that referential integrity
constraints are being satisfied. The SabaEntityBean class will
delegate calls to the SabaRelationship class within its ejbRemove(
) and ejbCreate( ) methods. Any implementation that a component
developer provides for these methods for a specific bean would have
to call super.ejbRemove( ) or super.ejbCreate( ) as
appropriate.
[0344] In the alternative embodiment, an attribute capturing the
list of relationships (where each item in the list is of type
SabaRelationship) will be defined in the SabaEntityBean class. By
default (i.e., at SabaEntityBean level), the list will be defined
to be empty. When component developers create an entity bean by
extending SabaEntityBean, they will be able to declaratively
specify relationships between the bean being created and the other
beans in the system. Additional relationships may be added to
existing beans too when a new bean is created.
[0345] In the alternative embodiment, besides lifetime management,
the declared relationships could also be used for navigational
purposes within the object model. As an example, consider a
situation where the SabaRegistration bean is related to the
SabaClass bean, which in turn is related to the SabaLocation bean.
One would like to be able to retrieve attributes of the location
(say, the map) of the class, given a registration. A new class,
SabaCompositeRelationship will allow one to compose navigational
paths in terms of basic SabaRelationship objects. Then, given a
source object and the name (or id) of a composite relationship, the
SabaCompositeRelationship class will be able to fetch the
destination object(s).
Vendor-Specific Wrappers
[0346] In the alternative embodiment, when some areas within the
J2EE specifications are still not standardized and are left up to
individual vendors for implementation, additional facilities will
be needed. To prevent vendor-specific implementation details from
migrating into SABA code, the BDK would provide a class
SabaJ2EEVendor that provides a wrapper around vendor-specific
implementations. SabaJ2EEVendor provides static methods that can be
used to perform activities in a vendor-neutral fashion in SABA
code. An example method in SabaJ2EEVendor is getInitialContext( ),
which encapsulates the logic for getting an initial context (at
present, the mechanism for this is vendor-dependent). To use a
particular vendor's implementation of J2EE specifications, one will
have to provide implementations of the methods in this class. By
default, the BDK will provide implementations of this class for a
few selected J2EE servers.
Miscellaneous Classes
[0347] In an alternative embodiment, in addition to the foregoing,
the BDK also provides the following utility classes that can be
useful for developing components: SabaProperties, DateUtil,
FormatUtil, LocaleUtil, SystemUtil, and Timer. Also, the following
exception classes are supported: SabaException,
SabaSecurityException, SabaFatal-Exception,
AttributeNotFoundException, and SabaRelationshipViolationException.
For logging purposes, the BDK provides a SabaLog class and for
debugging purposes, the BDK provides a SabaDebug class. The
functionality provided by the foregoing classes is similar to that
available currently.
[0348] The use of the various classes and interfaces discussed in
this section is described in the "Application Development Model"
section.
Services
[0349] A number of services are required by application developers
to develop robust, flexible, and scalable systems. A number of
these services are provided by the commercially available
application servers that host the EJB components. In the following
paragraphs we discuss the various services that an application
developer can rely on and how these services might be used.
Distributed Components
[0350] One of the key ingredients for building scalable systems is
the ability to distribute components. In the EJB model, different
beans can be deployed on different computers transparently.
Separation of interfaces from the implementation enables automated
generation of stubs and skeletons that hide the details of network
communications. A client application (or a bean that relies on
another bean) (Subsequent references to a client application should
be interpreted to be inclusive of beans that rely on other beans)
uses a naming service to first locate the bean and then interact
with it, thus making no assumptions about location of any given
component.
Naming
[0351] As alluded to in the previous paragraph, before using a
bean, it must first be located. All EJB application servers are
required to provide Java Naming and Directory Service (JNDI) access
for bean users. To use JNDI, a client application would typically
first get an "initial context" (driven by properties such as where
to find the EJB server, somewhat analogous to the JDBC connect
string for locating a database), and then using the context, look
up the home interface of the bean by its name. Using the home
interface, the client can find a specific instance of a bean,
create a new instance, or remove an instance. The naming service
would be used and the interaction would be the same even if the
bean instance is present locally (i.e., exists in the same Java
Virtual Machine) instead of being deployed on a remote machine.
[0352] The JNDI naming mechanism also obviates the need for the
SabaClassRegistry mechanism that is used at present. The client
application looks for a bean by a name (say, Authentication). Any
bean class that provides the implementation of the remote and home
interfaces can be deployed against that name in the application
server. Thus, at one installation, the default bean class
SabaPlatformLogin can be deployed with a name of Authentication,
whereas at some other installation, the bean class SabaLDAPLogin
can be deployed with the same external name to use a different
authentication logic.
Persistence
[0353] One of the benefits of using EJBs is that component
developers do not have to worry about persistence of data, as the
container hosting the (entity) beans can manage such persistence.
Automatic persistence service provided by the application server
enhances the productivity of bean developers, is more efficient at
runtime, and allows the bean's definition to be independent of the
type of data store used for persistence (e.g., a relational
database or an object-oriented database). A component developer
will be responsible for declaring part or all of the attributes of
an entity bean as persistent in its deployment descriptor, and then
mapping them to fields in a database at deployment time. The
interface and mechanism of such mapping would depend upon the
application server being used.
[0354] The bean is automatically saved to the persistent store when
it is created by a client application using the create( ) method,
and when the container decides to synchronize the bean's state with
the database if the bean's data has been changed by the client
application. The container's decision is based on such factors as
transactions, concurrency, and resource management. The container
will remove the data from persistent store when the remove( )
method is called by a client on an entity bean.
Concurrency
[0355] A component developer does not have to worry about
concurrent access to an entity bean from multiple transactions
(such as from several client applications). It is the
responsibility of the container hosting the bean to ensure
synchronization for entity objects. Indeed, use of the keyword
synchronized is prohibited by the EJB Specification. Concurrent
access for session beans is not meaningful, since by definition an
instance of a stateful session bean can be used by only one client
and stateless session beans do not maintain any data that needs to
be shared.
Transactions
[0356] For transactions, an application developer has two options:
1) to explicitly demarcate the boundaries of a transaction, or 2)
to use declarative transactional management available with EJBs.
Use of declarative transactional management is cleaner and is
strongly recommended. In this case, the level of granularity for
managing transactions corresponds to methods in a bean. Instead of
interleaving transaction boundaries within business logic,
transactional attributes are separately declared in the bean's
deployment descriptor (for a specific method, or as the bean's
default) as one of the following six options: TX_NOT_SUPPORTED,
TX_SUPPORTS, TX_REQUIRED, TX_REQUIRES_NEW, TX_MANDATORY,
TX_BEAN_MANAGED. Details of these can be found in books on EJB.
Security
[0357] As discussed earlier, application developers can use a
stateless session bean, SabaPlatformLogin, to authenticate a user.
In the deployment descriptor for every bean, access control entries
are defined which list the identities (users or roles) that are
allowed to invoke a specific method (alternatively, an access
control list can act as the default for all the methods in a bean).
According to EJB Specification, each client application accessing
an EJB object must have an associated java.security.Identity object
(generally associated at login time). The general Security system
used in the present invention was discussed in more detail
above.
Read/Write/Arbitrary Privileges
Search
[0358] To locate an instance of an entity bean, each entity bean
provides a method findByPrimaryKey( ) in its home interface. In
addition, other finder methods (which must be named in accordance
with the pattern find<criterion>) can also be provided. With
container-managed persistence, the container generates the
implementations of such methods automatically at deployment time.
The mapping of finder methods to the database is vendor-dependent
at present, though a standardized syntax for the same is a goal of
EJB 2.0 Specification effort. In the meantime, a developer can
implement the finder methods in terms of findUsingRQL( ) and
findUsingRQLURI( ) methods available in SabaEntityBean.
Logging & Debugging
[0359] A component may be used by multiple applications in an
interleaving fashion.
[0360] An application could have components distributed over
multiple computers--how to assemble a unified log--use a "log
server" bean--heavy performance price, impacts debugging class
too.
[0361] Turning on and off debugging on a component basis. Mechanics
of how to do it without having runtime checks every time a method
in Debug is called. What if one app wants a component to turn
debugging on whereas another wants to turn it off.
Application Development Model
[0362] In the alternative embodiment, to develop an application
using the BDK, an object model of the application domain should be
first developed, retaining a separation between objects that
represent business processes and those that represent business
data. The two types of objects, obviously, map to session beans and
entity beans in EJB parlance. A controller object, for instance,
would indicate a session bean whereas an object that persists its
data would indicate an entity bean. An application would typically
also include UI components (such as JSP pages or servlets) which
would use such business components. Thus, there are two primary
roles from an application development standpoint:
[0363] 1. component developer, and
[0364] 2. component user.
[0365] It is possible that an individual may play both the roles.
Indeed, a component developer may need to rely on another
component, and thus be a user as well as a developer. We will first
look at the role of a component developer in the next subsection,
and then look at the responsibilities of the component user.
Finally, we will look at how an application can be packaged in this
alternative embodiment.
Component Developer
[0366] To create a component, a developer needs to perform the
following steps.
[0367] 1. Define the remote interface of the component.
[0368] 2. Define the home interface of the component.
[0369] 3. Define the bean class.
[0370] 4. Create the deployment descriptor of the component.
[0371] As an example, one will build a simple SabaPerson component.
SabaPerson is a container-managed entity bean useful for explaining
some basic concepts in EJBs and the BDK framework. One then
illustrates issues surrounding business logic coding, transactions,
and persistence in a question-answer format. Note that for
simplicity's sake, package, import, try/catch/finally, etc.,
statements are not included in the following code segments.
The Remote Interface
TABLE-US-00020 [0372] public interface SabaPerson extends
ISabaRemote { public String getFullName( ) throws RMIException;
public String getFirstName( ) throws RMIException; public String
getLastName( ) throws RMIException; public void setFirstName(String
name) throws RMIException; public void setLastName(String name)
throws RMIException; }
[0373] The remote interface provides the business methods or the
world's view of the component. In our case, we have a single method
that a client can use to get the person's full name. Also recall
that ISabaRemote already declares setAttrVal( ) and getAttrVal( )
methods for manipulating the attribute values (such as fName and
lName declared in the bean class), so they don't need to be
declared again.
The Home Interface
TABLE-US-00021 [0374] public interface SabaPersonHome extends
ISabaHome { public SabaPersonEJB findByPrimaryKey(SabaPrimaryKey
id) throws FinderException, RMIException; public Collection
findByName(String fName, String lName) throws FinderException,
RMIException; public SabaPersonEJB create(String fName, String
lName) throws CreateException, RMIException; }
[0375] For container-managed beans, the container automatically
provides an implementation of the findByPrimaryKey( ) method and
generates the code for other finders (such as findByName( )) from
an external description, which pending EJB 2.0 Specification, is
vendor-specific.
The Bean Class
TABLE-US-00022 [0376] public class SabaPersonEJB extends
SabaEntityBean { public String id; public String fName; public
String lName; public String getFullName( ) throws RMIException {
return (fName + lName); } public String getFirstName( ) throws
RMIException { return (String) getAttrVal("fName"); } public void
setFirstName(String name) throws RMIException { setAttrVal("fName",
name); } ... public void ejbCreate(String fName, String lName) {
this.id = IDGenerator.getNewID( ); this.fName = fName; this.lName =
lName; } public void ejbPostCreate(String fName, String lName) { //
No action needs to be taken. } }
[0377] The bean class provides implementations for the business
methods declared in the remote interface. Note that the fields in
the bean class are declared to be public. The EJB Specification
require this for container-managed persistent fields. Furthermore,
this is also required by the setAttrVal( ) and getAttrVal( )
methods for fields that should be accessible via this methods (the
methods use reflection to locate the fields). The consequences of
such visibility are limited, however, because the user of a bean
only interact with the bean through the home and remote interfaces.
It is not possible for a client to directly assign values to or
retrieve values from such public fields without going through the
accessor and mutator methods defined in the remote interface.
[0378] For each different signature of create( ) method in the home
interface, corresponding ejbCreate( ) and ejbPostCreate( ) methods
need to be defined in the bean class. The code for the bean class
is consistent with this requirement.
The Deployment Descriptor
[0379] In EJB Specification v1.1 (which can be found at the
java.sun.com web site), the deployment descriptor is an XML file
that declares such things as container-managed persistent fields
and security and transactional characteristics of the bean and its
methods. The following example shows part of a deployment
descriptor.
TABLE-US-00023 <entity> <description> This is part of
the deployment descriptor of the SabaPerson entity bean.
</description> <ejb-name>SabaPerson</ejb-name>
<home>com.saba.examples.SabaPersonHome</home>
<remote> . . . </remote> <ejb-class> . . . </
ejb-class > <prim-key-class> . . . </ prim-key-class
> <persistence-type>Container</persistence-type>
<cmp-field>id</cmp-field>
<cmp-field>fName</cmp-field>
<cmp-field>lName</cmp-field> . . .
<container-transaction> <method>
<ejb-name>SabaPerson</ejb-name>
<method-name>*</method-name> </method>
<trans-attribute>Supported</trans-attribute>
</container-transaction> </entity>
[0380] In EJB Specification 1.0, the deployment descriptor is a
text file with a somewhat different format. The deployment
descriptor is generally created using a GUI tool, generally
supplied by EJB Server vendors. Additional information on
deployment descriptors can be obtained from EJB literature and tool
manuals.
[0381] Depending upon the kind of business logic, there are
different ways of encoding business logic in EJBs. Of course,
implementation of the methods declared in the remote interface of a
session bean or an entity bean encodes business logic. In addition,
EJB provides "hooks" or callback methods for implementing
additional types of business logic. We have already seen the
ejbCreate( ) and ejbPostCreate( ) methods that one can use in a
manner analogous to insert triggers in a relational database.
Similarly, the method ejbRemove( ) (implemented with an empty body
in SabaEntityBean and SabaSessionBean) can be overridden to encode
logic related to deletion of a bean. For example, if we wish to
encode the logic that if a person is removed, all the class
registrations for that person should also be removed, we can
override the ejbRemove( ) method within SabaPerson in the following
manner. The ejbRemove( ) method is called just prior to actual
removal of the data from the persistent store.
TABLE-US-00024 public void ejbRemove( ) { /* Locate the home
interface (regnHome) for the ** SabaRegistration bean (code not
shown) */ Collection regns = (Collection)
regnHome.findByPersonID(this.id); Iterator iter = regns.iterator(
); while (iter.hasNext( )) { SabaRegistrationEJB registrn =
(SabaRegistrationEJB) iter.next( ); registrn.remove( ); } }
[0382] Other callback methods are ejbLoad( ), ejbStore( ),
ejbActivate( ), and ejbPassivate( ).
[0383] In the alternative embodiment, transactional integrity can
be maintained as follows. Consider a session bean which, as part of
its remote interface, has declared a method cancelClass( ) that
encapsulates the business process of canceling a class. As part of
class cancellation, we also wish to, say, remove the registration
records of the persons registered for the class. The registration
information is maintained by SabaRegistration entity beans. Hence,
within the implementation of cancelClass( ), besides updating some
attribute of the SabaClass entity bean to indicate cancellation, we
would also encode logic for finding the SabaRegistration entity
beans corresponding to that class and then removing them. However,
either all these activities must succeed atomically, or no change
to persistent store should be made (i.e., the activities constitute
a transaction). This would be accomplished by declaring a
transactional attribute of TX_REQUIRED for the method cancelClass(
) in the bean's deployment descriptor. If the calling client or
bean already has a transaction started, the method will then be
executed within the scope of that transaction; otherwise, a new
transaction will automatically be started for this method.
How can
[0384] In an alternative embodiment, complex data types can be
persisted for container-managed entity beans as follows. Suppose
there is an entity bean with an attribute that has an array of
strings as a data type. Since relational databases do not support
such a data type, one cannot directly map the attribute to some
column in a database. However, at save time, one can potentially
convert the array into a single String by concatenating the
elements within the array and using a marker character to delineate
various entries. Then, at retrieval time, one can look for the
marker character and reconstitute the array. Entity beans provide
two callback methods, ejbStore( ) and ejbLoad( ) that can be used
for such a purpose. SabaEntityBean by default provides empty
implementations of such methods. An application developer can
override these methods within the definition of a bean and thus
persist complex data types.
[0385] In the alternative embodiment, every class in an application
does not have to be a bean. Indeed, with the overhead of locating a
bean through a naming service and going through the home and remote
interfaces of a bean to perform useful work would negatively impact
performance (though some servers will optimize the process for
beans located within the same virtual machine). The application
developers can implement selected classes as helper classes and not
as beans. Sun Microsystems' J2EE Application Programming Model
identifies certain instances where helper classes are applicable.
One such example is dependent classes that can only be accessed
indirectly through other classes (beans). Sun's J2EE APM offers
CreditCard and Address classes as examples of a dependent
classes.
[0386] EJBs are packaged as EJB jar files that are comprised of the
class files for the bean class, the home interface, the remote
interface, the primary key class (if applicable), in addition to
the deployment descriptor and a manifest. The jar file can be
created using the jar application supplied with JDK, or by using
some GUI front-end utility provided by the J2EE server being used.
The deployment mechanism varies with the servers. For Weblogic
server, an entry can be made in the weblogic.properties file; for
Sun's reference implementation, the deploytool utility can be used
to achieve this in an interactive manner.
[0387] At present, the EJB Specification does not provide a
mechanism for declaring such constraints, and this would have to be
achieved programmatically in the create( ) and mutator method(s) of
the entity beans.
Component User
[0388] As described above, in the alternative embodiment, a partial
example of usage of a component was described in the context of
business logic encoding. This section provides a fuller picture of
how a component is used in an alternative embodiment, by either
another bean or a client application. The primary steps in both the
cases are the same: [0389] 1. locate the home interface of the
bean; [0390] 2. using the home interface, create a new instance or
find one or more existing instances of the bean; and [0391] 3.
invoke the bean's methods to accomplish tasks.
[0392] To locate the bean, JNDI is used. There are some variations
in how JNDI calls are used with different EJB servers. Here we use
the getInitialContext( ) method in the SabaJ2EEVendor class for
locating the SabaRegistration bean.
TABLE-US-00025 InitialContext ctxt =
SabaJ2EEVendor.getInitialContext( ); Object objref =
ctxt.lookup("SabaRegistration"); SabaRegistrationHome regnHome =
(SabaRegistrationHome) PortableRemoteObject.narrow(objref,
SabaRegistrationHome.class);
[0393] Once the home interface of the bean is so located, we can
use it to create new instances of the bean or find existing ones.
In an earlier example, we had used the home interface for finding
instances of a bean. Another example, this time for creating an
instance, is presented below.
TABLE-US-00026 SabaRegistration regstrn = regnHome.create(personID,
classID);
[0394] Subsequently, we can invoke business methods of the bean
simply as follows. [0395] regstrn.setAttrVal(feePaid, true);
[0396] In addition to the foregoing, additional methods
(implemented by the bean container) are available for getting a
bean's metadata (from which its primary key class, remote interface
class, etc. can be obtained), comparing two beans for identity,
etc. Many of these methods are used in building tools, such as
those for deployment purposes. If additional information about
these methods is needed, please consult the available EJB
literature.
[0397] Those skilled in these arts will understand that various
other alternative embodiments of a business application server
system and related development kit for developers, may be designed
around these basic concepts without deviating from the unique
features provided by applicants in this invention.
Security System
[0398] In a preferred embodiment of the present invention, the
Platform's BDK 519 provides an extremely powerful model for
assigning security; that is, defining the sets of allowed
operations that groups of users can perform. It supports both
extremely sophisticated definitions of an allowed operation and a
scalable model for assigning and partitioning security.
Specifically, the following features are provided: [0399] Security
operations can be specified according to either the general class
of business object or to specific, individual business objects.
[0400] Support for both shared security operations (view, update,
delete, etc) and business-object specific security operations.
[0401] Security operations can be assigned based on a customizable
partitioning of business objects into domains. [0402] Security
operations can be assigned based on either universal or
domain-specific user groupings.
DEFINITIONS
[0403] The following concepts are central to the Platform's
Security Model.
[0404] A Security List Member is any entity that can be assigned
privileges in the system. Members can be can be individual users of
the system (employees or customers); they can also be associated
with generic roles, such as a system administrator, or even an
automated process, such as an Interconnect ChangeManager.
[0405] A Privilege is a set of one or more possible security
operations. There are several types of privileges as shown below in
Table 1:
TABLE-US-00027 TABLE 1 Category Description Example Atomic
Privilege The most fine-grained form Create, Delete of privilege.
Defines a single type of security operation. Component An Atomic
Privilege Create Class, Privilege applies to a specific View
Registrations, category of business object Confirm Internal Order
Instance Privilege An Atomic Privilege View the "Monthly applied to
a specific Cancellations" Report business object Complex Privilege
A grouping of one or more Create, modify, and privileges delete
classes
[0406] The Platform 501 supports several pre-defined atomic
privileges that apply to all business objects. The pre-defined
atomic privileges are shown below in Table 2.
TABLE-US-00028 TABLE 2 Privilege Description New Create a new
instance of this business object View View summary or detail
information about an existing business object Edit Change
information about an existing business object Delete Delete an
existing business object Change Domain Set the domain of an
existing business object
[0407] Specific categories of business objects can also define
additional privileges specific to that category. For example, the
following component privileges only apply to the "Purchase Order"
business object:
[0408] Change Expiry Date
[0409] Change Initial Credit
[0410] Change Status
[0411] Change Terms
[0412] Domains are the Platform's 501 partitioning mechanism for
business objects. Domains allow users to define a hierarchical
structure that models their organization or business, for example,
based on geography or division.
[0413] For example, FIG. 20 shows a three-domain organization, with
a root "World" domain and two child "US" and "Europe" domains.
[0414] All business objects are assigned a specific domain and
belong to that domain. In turn, security privileges are assigned on
specific domains. The domain hierarchy is automatically enforced
during security checks. This means that users who have access to a
domain can access objects in that domain, and that users who have
access to ancestors of a given domain also have access to objects
in that domain.
[0415] Extensions to the basic domain model may include the ability
to define multiple, independent domain axes. For example, one
domain hierarchy might be based on geography, another on business
function.
[0416] Security Lists are the mechanism by which members are
matched with privileges. A Security List defines a set of
domain-specific privileges and a set of list members. Security
Lists are created in a two-step process as follows: [0417] First, a
set of privileges are added to a security list, where each
privilege is applied to a specific domain. A privilege within a
security list--that is, a privilege applied to a specific
domain--is known as a "granted privilege." [0418] Second, a set of
members are added to a security list.
[0419] Privileges are calculated at runtime based on all the
security lists a user belongs to. At least one of the lists must
contain a required privilege in the appropriate domain. This
combined use of privileges and security lists supports two
paradigms for administering security across domains:
[0420] 1. A centralized approach wherein global administrators
define security lists that contain a set of (privilege, object,
domain) triples, that is, one security list can apply across
different domains. The same global administrators assign members to
security lists.
[0421] 2. A decentralized approach wherein global administrators
define complex privileges that contain a set of (privilege, object)
pairs with no domain information. These serve as "security roles",
effectively, global security lists that are domains-independent.
Administrators for individual domains then define domain-specific
security lists containing these privileges. The domain
administrators assign members in their domain to security
lists.
[0422] The following example shows how privileges work in
practice.
[0423] Two security lists are shown below in Table 3 and Table 4
containing the following granted privileges:
TABLE-US-00029 TABLE 3 "Customer" Security List Privilege Business
Object Category Domain View Class World Create Order US
TABLE-US-00030 TABLE 4 "US Instructor" Security List Privilege
Business Object Category Domain View Class World Create Class US
Delete Class US Create Conference Room US View Conference Room
World Schedule Projector US
[0424] For purposes of this example, also assume that the instances
of business objects shown below in Table 5 exist:
TABLE-US-00031 TABLE 5 Business Object Category Business Object
Domain Class English 101 US Class Spanish 101 Europe Conference
Room Purple Room World Conference Room Lavender Room US Projector
Projector 1520 Europe Projector Projector 1120 US
[0425] If User1 only belongs to "Customer" security list, User1 can
perform the following operations: [0426] View Class "English 101"
[0427] View Class "Spanish 101" [0428] Create a new Order for Class
"English 101"
[0429] However, User 1 is not permitted to perform the following
operations: [0430] Order the class "Spanish 101" to be taken in
Europe [because this would require a Order with a domain of
"Europe"] [0431] View the Purple Room [0432] View the Lavender
Room
[0433] If User2 belongs to both the "Customer" and "US Instructor"
security lists, then User2 can perform the following operations:
[0434] View Class "English 101" [0435] Create a class "English 101"
in the "US" domain [0436] View the Lavender Room [0437] View the
Purple Room [0438] Schedule Projector 1120
[0439] However, User2 is not permitted to perform the following
operations: [0440] Create a new Order for Class "Spanish 101" to be
taken in Europe [0441] Create a class "French 101" in the "Europe"
domain [0442] Schedule Projector 1520
[0443] The Persistence Layer of the BDK 519 automatically takes
account of the predefined atomic privileges (new, view, etc) in its
behavior. Thus, search results using standard finders will only
return objects for which a user has view privileges, and update
operations for which a user does not have privileges will
automatically throw a Security exception. In addition, the BDK 519
provides the ability to explicitly query the security model using
the API described below.
Security System API
[0444] The BDK 519 provides a Java-based API for managing security.
As described in the BDK section, this API uses an EJB-style session
manager named "SabaSessionManager" and a set of helper classes.
[0445] The API includes:
[0446] 1. A set of interfaces representing the basic concepts in
the security model.
TABLE-US-00032 // IPrivilege - The base class of privilege. A
Privilege is anything that can be added to a Security List. public
interface IPrivilege; // IAtomicPrivilege - A single allowable
operation public interface IAtomicPrivilege extends IPrivilege; //
IComponentPrivilege - A single allowable operation on a specific
object class. public interface IComponentPrivilege extends
IAtomicPrivilege; // IInstancePrivilege - A single allowable
operation on a specific object instance. public interface
IInstancePrivilege extends IComponentPrivilege; //
IComplexPrivilege - A structured privilege, capable of grouping
other atomic or complex privileges. public interface
IComplexPrivilege extends IPrivilege, IHandle; // Domain - A
business object representing an entry in the Domain hierarchy
public interface Domain extends IHandle; // ISecurityListMember is
any interface that can be a member of a security list, including
IRole, IParty (IPerson or IOrganization), or IGroup public
interface ISecurityListMember extends IHandle; // ISecurityList
matches granted privileges to a set of members public interface
ISecurityList extends IHandle;
[0447] 2. A set of concrete classes capturing the available
privileges in the system. These classes are application-dependent;
i.e. there are one set of classes associated with the Learning
application built on Platform, another set associated with the
Performance application, etc.
[0448] For example:
TABLE-US-00033 public class InstancePrivileges implements
IInstancePrivilege { /* Define the set of common atomic privileges
that apply to all objects in the system. */ public static final int
kEdit = 2; public static final int kDelete = 3; public static final
int kView = 6; } public class ComponentPrivileges implements
IComponentPrivilege { /* Define the set of common atomic privileges
that apply to all components in the system. Notice that this class
includes all atomic privileges that apply to instances */ public
static final int kNew = 1; public static final int kEdit = 2;
public static final int kDelete = 3; public static final int kView
= 6; } public class PurchaseOrderPrivileges extends
ComponentPrivileges { // Privileges specific to the Purchase Order
business object public static final int kChangeDomain = 7; public
static final int kChangeStatus = 11; public static final int
kChangeTerms = 12; public static final int kChangeInitialCredit =
13; public static final int kChangeExpiryDate = 14; public static
final int kChangeCurrency = 15; }
[0449] 2. The interface of the manager used to create and manage
security lists.
TABLE-US-00034 public interface SabaSecurityManager extends
ISabaRemote { /* methods for creating and updating security lists
*/ public ISecurityList createSecurityList(SecurityDetail detail);
public SecurityDetail getDetail(ISecurityList theSecurityList);
public void update(ISecurityList theSecurityList, SecurityDetail
detail); public void remove(ISecurityList theSecurityList); /*
methods for adding & removing privileges to security lists */
public void addPrivilege(ISecurityList theList, IPrivilege
thePrivilege, Domain theDomain); public void
removePrivilege(ISecurityList theList, IPrivilege thePrivilege,
Domain theDomain); /* methods for adding & removing members
from security lists */ public void addMember(ISecurityList theList,
ISecurityListMember theMember); public void
removeMember(ISecurityList theList, ISecurityListMember theMember);
/* methods to check privileges */ public boolean
isMember(ISecurityList theList, ISecurityListMember theMember);
public boolean hasPrivilege(ISecurityListMember theMember,
IAtomicPrivilege thePrivilege, Domain theDomain); public Collection
getPrivileges(ISecurityListMember theMember, IComponent
theComponent, Domain theDomain); /* standard finder */ public
ISecurityList findSecurityListByKey(String id); public Collection
findSecurityListByName(String name); public Collection
findAllSecurityLists( ); } /* SabaSecurityManager */
[0450] The following code fragment demonstrates how the Security
API can be used to create a new security list, assign users to that
security list, and check privileges for that user. Note that this
code example uses several other session bean managers, such as a
DomainManager and PartyManager, provided as part of Platform.
TABLE-US-00035 /* Step 1: create a security list */ String privName
= "Guest"; String privDescription = "Guest login and access";
Domain domain =
theDomainManager.findDomainByKey("domin000000000001000") ; String
domainID = domain.getId( ); SecurityDetail theDetail = new
SecurityDetail(privName, privDescription, domainID); ISecurityList
securityList = theSecurityManager.createSecurityList(theDetail); /*
Step 2: grant privileges by adding them to the list */ IComponent
classesComponent = theComponentManager.getComponent("Classes"); /*
create atomic privileges and add them */ IPrivilege viewClasses =
(IPrivilege) new ComponentPrivileges(ComponentPrivileges.kView,
classesComponent); theSecurityManager.addPrivilege(securityList,
viewClasses, domain); IComponent groupComponent =
theComponentManager.getComponent("Product Group"); IPrivilege
viewGroups = (IPrivilege) new
ComponentPrivileges(ComponentPrivileges.kView, classesComponent);
theSecurityManager.addPrivilege(securityList, viewGroups, domain);
/* Step 3: assign a member to the security list */
ISecurityListMember member = (ISecurityListMember)
thePartyManager.findEmployeeByKey("emplo000000000001000" );
theSecurityManager.addMember(securityList, member); /* Step 4:
check a user's privileges */ IPrivilege editClassPriv =
(IPrivilege) new ComponentPrivileges(ComponentPrivileges.kEdit,
classesComponent); boolean canEditClasses =
theSecurityManager.hasPrivilege(member, editClassPriv, domain);
Best Mode
[0451] In a preferred embodiment, the Platform's BDK security API
focuses on the database structures and SQL used to store and query
security information. It also touches on the algorithms used in
implementing the Java API.
[0452] Information related to security is stored database tables as
shown below. The Platform's BDK Security System uses Java code to
read and write values to these database tables.
[0453] fgt_domain stores all domains as shown below in Table 6.
TABLE-US-00036 TABLE 6 Column Name type Required? Description Id
OBJECTID y Description varchar(255) n Long descriptive string for
the domain. Name varchar(25) y Name of the domain Parent_id
OBJECTID N ID of the parent domain
fgt_ss_privs stores all atomic privileges as shown below in Table
7a.
TABLE-US-00037 TABLE 7a Column Name Type Required? Description Id
OBJECTID y object_type OBJECTID Y object id (data dictionary class
id) to which the privilege applies. priv_name varchar(80) Y a
description string for the privilege. priv_seq INT y a number which
identifies the type of privilege. 1 => New 2 => Edit 3 =>
Delete 4 => Save etc. Note: 1-5 common to all classes 11 onwards
-- class specific.
[0454] For example, in Table 7b below, the following data captures
the available privileges for the Purchase Order business object.
Notice that the values in the priv_seq column directly correspond
to the constants defined by PurchaseOrderPrivileges class defined
in the Java API.
TABLE-US-00038 TABLE 7b Id object_type priv_name priv_seq
ssprv000000000001008 pycat000000000001036 New 1
ssprv000000000002008 pycat000000000001036 Edit 2
ssprv000000000003009 pycat000000000001036 Delete 3
ssprv000000000010175 pycat000000000001036 View 6
ssprv000000000010224 pycat000000000001036 Change Domain 7
ssprv000000000007120 pycat000000000001036 Change Status 11
ssprv000000000007121 pycat000000000001036 Change Terms 12
ssprv000000000007122 pycat000000000001036 Change Initial 13 Credit
ssprv000000000007123 pycat000000000001036 Change Expiry 14 Date
[0455] fgt_list stores all security lists as shown below in Table
8a.
TABLE-US-00039 TABLE 8a Column Name Type Rq? Description Id
OBJECTID Y description varchar(255) N Description of this list Name
varchar(25) Y Name of the list owner_id OBJECTID N The owning
object of this list if any. Security BOOLEAN Y 0 = Not a security
list, 1 = Security List.
[0456] For example, in Table 8b below, the following data defines a
security list to capture generic user privileges:
TABLE-US-00040 TABLE 8b ID name description security
lista000000000002003 User A generic low-privileged user 1
[0457] fgt_list_entry stores all members of a security list as
shown below in Table 9.
TABLE-US-00041 TABLE 9 Column Name Type Rq? Description id OBJECTID
Y list_id OBJECTID Y Foreign key to a security list person_id
OBJECTID Y Foreign key to a list member. The object ID may be a
person, role, or group.
[0458] fgt_ss_grants stores all granted privileges as shown below
in Table 10.
TABLE-US-00042 Column Name Type Rq? Description id OBJECTID y
granted_on_id OBJECTID y Foreign key to the business object class
or instance on which this privilege is granted. granted_to_id
OBJECTID y Foreign key to the security list on which this privilege
is granted. privs varchar(50) y 50 character bitmap containing the
granted privileges. domain_id OBJECTID N Foreign key to the domain
on which this privilege is granted.
[0459] Notice that this schema shown in Table 10 stores all atomic
privileges on a (object, domain, list) triple in a single row by
appending the integer keys of the atomic privileges into a single
string. Notice also that the schema shown in Table 10 can capture
both:
[0460] 1) privileges on business object classes, by storing the
data dictionary primary key of the class in the granted_on_id
column.
[0461] 2) privileges on business object instances, by storing the
object id of the instance in the granted_on_id column.
[0462] For example, the following row from Table 10 describes a
grant that allows members of the "Users" security list to create
and view orders, but not edit or delete them. The "ddcls" prefix
(for "data dictionary class") on the granted_on_id value indicates
that this OBJECTID refers to a business object class. The 1.sup.st
and 6.sup.th bits of the privs flag are on, providing create and
view privileges only.
TABLE-US-00043 ID granted_on_id granted_to_id ssgrn000000000001264
ddcls000000000001055 lista000000000002003
TABLE-US-00044 Privs domain_id
10000100000000000000000000000000000000000000000000
domin000000000000001
[0463] The following row from Table 10 describes a grant that
allows the same list to execute a specific report. The "reprt" (for
"report") prefix on the granted_on_id value indicates that this
OBJECTID refers to a specific instance of the Report business
object. The 11.sup.th bit of the privs flag is on, meaning the
grant gives Execute privileges only.
TABLE-US-00045 Id granted_on_id granted_to_id ssgrn000000000202056
reprt000000000001000 lista000000000002003
TABLE-US-00046 Privs domain_id
00000000001000000000000000000000000000000000000000
domin000000000000001
[0464] The Platform's BDK Security System also utilizes an
addPrivilege( ) method. The addPrivilege( ) method has different
logic depending on whether a row already exists in fgt_ss_grants
for the combination of security list, business object, and domain.
If a row exists, it retrieves the existing row, sets the additional
bits defined by the IPrivilege parameter, then updates the row. If
no row exists, it creates a empty privilege bitmap, sets the bits
defined by the IPrivilege parameter, then inserts a row.
[0465] The Platform's BDK Security System also utilizes an
hasPrivilegeo method. The addPrivilege( ) method executes a SQL
query to return all privilege bitmaps for each security list the
user belongs to that match the target object and domain parameters.
It iterates through each bitmap and returns true if the privilege
has been set in any one. The SQL query that is executed is:
TABLE-US-00047 /* select all of a user's grants on an class in a
given domain. parameter 1 = person id parameter 2 = class id
parameter 3 = domain id */ select g.id, g.privs from fgt_ss_grants
g, fgt_list l, fgt_list_entry e where e.person_id = @@001 and
e.list_id = l.id and l.security = 1 and " e.person_id = @@001 and
e.list_id = l.id and l.security = 1 and " + g.granted_to_id = l.id
and g.granted_on_id = @@002 and g.domain_id = @@003
[0466] The BDK Persistence layer also contains code that directly
accesses these database tables to check security privileges. A
utility class, SabaPrivileges, contains a hasPrivs( ) method that
is called at predefined points by the SabaObject and SabaEntityBean
implementations, including whenever objects are saved and restored.
This method has the following signature:
TABLE-US-00048 public boolean hasPrivs(String objectID, String
classID, String domainID, int privToCheck, boolean anyDomain)
[0467] SabaPrivileges contains a Java hashtable that caches
privilege for each business object in the system. The hasPrivs( )
method iterates through these privileges to look for a match, using
logic similar to the SabaSecurityManager.hasPrivilege( )
method.
[0468] If the cache is empty, SabaPrivileges queries the database
to load the appropriate privileges. The SQL used is the
following:
TABLE-US-00049 select s.granted_on_id granted_on, substr(
to_char(decode(sum(to_number(substr(s.privs, 1, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs, 2, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs, 3, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs, 4, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs, 5, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs, 6, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs, 7, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs, 8, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs, 9, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs,10, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs,11, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs,12, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs,13, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs,14, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs,15, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs,16, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs,17, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs,18, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs,19, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs,20, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs,21, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs,22, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs,23, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs,24, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs,25, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs,26, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs,27, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs,28, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs,29, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs,30, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs,31, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs,32, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs,33, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs,34, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs,35, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs,36, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs,37, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs,38, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs,39, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs,40, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs,41, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs,42, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs,43, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs,44, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs,45, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs,46, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs,47, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs,48, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs,49, 1))),0,0,1)) ||
to_char(decode(sum(to_number(substr(s.privs,50, 1))),0,0,1)) ,1,50)
privs, t.node_id domain_id from fgt_ss_grants s, fgt_list_entry l,
tpt_dummy_flat_tree t where l.person_id = @001 and s.granted_on_id
= @003 and l.list_id = s.granted_to_id and s.domain_id =
t.related_to and (l.group_label is null or l.group_label = @002)
group by s.granted_on_id, t.node_id
[0469] The SQL used in this query has two unique features: [0470]
It uses a table called tpt_dummy_flat_tree that stores the
parent/child relationships for all domains in the system. This
allows it to include a join that obtains privileges for both the
specified domain and all its parents. [0471] It checks the value of
the privs field bit by bit, and concatenates the results together
to form a new bitmap that is the union of the bitmap fields for the
specified domain and all its ancestors.
[0472] The following example data in tpt_dummy_flat_tree shown in
Table 11 defines the relationships between three domains, where
domin000000000000001 is the top-level parent, domin000000000001000
is its child, and domin000000000001001 is its grandchild.
TABLE-US-00050 TABLE 11 NODE_ID RELATED_TO R REL_LEVEL
domin000000000000001 domin000000000000001 I 1 domin000000000001000
domin000000000000001 A 2 domin000000000001000 domin000000000001000
I 1 domin000000000001001 domin000000000000001 A 3
domin000000000001001 domin000000000001000 A 2 domin000000000001001
domin000000000001001 I 1
WDK Server
[0473] The Web Content Server 800 enables the present invention to
interact with users regardless of the users hardware platforms,
locations, and software systems. The Web Content Server 800 allows
the present invention to overcome the difficulties of prior art
systems associated with having an infrastructure which is tightly
coupled to application products, specific hardware platforms and
specific Operating systems and related services.
[0474] The Web Content Server 800 can allow the present invention
to interface with many other industry standard software programs to
make the exchange and flow of data easy and accurate, and enables
interconnection with external systems, special networks, like
SabaNet, and the Internet.
[0475] The Web Content Server 800 is web-enabled and provides a
unified set of interfaces for interacting with web based users as
well as other users.
[0476] The Web Content Server 800 can also allow vendors/developers
to develop applications on the Platform, make use of core
technology for information matching and distribution, and provide
standardized access to connectivity with other systems and
platforms in a users network.
[0477] As shown in FIG. 8A, one embodiment of an Web Content Server
800 provides an interface between users 802, 804, and 806 and the
Platform. The Web Content Server 800 preferably includes an engine
808, style sheet control system 810 for various user display
protocols, a JAVA Virtual Machine 812 and the related runtime
support.
[0478] The Style Sheet Control System 810 contains mechanisms to
manipulate various kinds of display style sheets, to generate and
execute web links, to manage dynamic content generation and dynamic
generation of Javascript. The Style Sheet Control System 810 also
can allow vendors/developers to modify, add, or delete the
mechanisms in the Style Sheet Control System 810. Thus,
vendors/developers can customize the presentation of data to the
users.
User Generation of Web Content
[0479] Web Content Server 800 can also provide the platform's web
content generation engine for use by users to create, render, and
present web content while improving the dynamic acquisition of data
from a variety of sources followed by its reformatting and display
via style sheets. Using web standards for XML and XSL, Web Content
Server 800 provides a user with a customizable framework for
decoupling data from presentation, and generating web content in a
variety of formats, from standard HTML to WML.
[0480] The Web Content Server 800 provides a "page engine" 808
which allows users (such as developers, consultants and customers)
to build web content using a separation between Model, Widget, and
View instructions. The engine 808 separates data production,
interaction elements and display information, and maintains these
aspect of page production in different files.
[0481] The engine 808 supports three components: (a) Widgets, which
are reusable interactive components such as buttons and data entry
fields; (b) Models, which encompass the data and user operations
used by the application (Data can be simple Strings or complex
objects); and (c) Views, which use style sheets to define and
control the presentation of output to the user.
[0482] Using the system 808 provides, among other things, the
following advantages for a user:
[0483] Improve maintainability of web content.
[0484] Partition web content development between users (such as
component developers, Java developers, and UI developers).
[0485] Provide easy and extensive customizability by users.
[0486] Improve productivity of building web content.
[0487] Provide improved authoring and debugging support.
[0488] Provide the infrastructure for targeting alternate
deployment platforms (ie palmtops).
[0489] In one embodiment, the engine 808 uses XML, XSLT (eXtensible
Stylesheet Language Transformations), and RDF (Resource Description
Framework), built round a publishing framework called Cocoon to
enable the functionality of Web Content Server 800.
[0490] The engine 808, in conjunction with a set of tools,
utilities, APIs, and predefined widgets and views, acts as a
platform and provides the user with a set of tools, tag and widget
libraries, Java classes, and XSL style sheets. Tools included with
the platform 808 help users perform the following activities: (a)
Authoring--users need to create and maintain control files, model
files, widget files, and view files; (b) Debugging--the process
starting with obtaining data and ending with viewing is involved so
having tools or methods for debugging problems is essential; and
(c) Customization--customizing the final product can certainly be
accomplished with the tools used for authoring and debugging, but
additional tools can radically simplify tasks like product upgrades
or performing simple customizations.
[0491] The platform 808 allows content, logic and style to be
separated out into different XML files, and uses XSL transformation
capabilities to merge them resulting in the automatic creation of
HTML through the processing of statically or dynamically generated
XML files. The platform 808 can also generate other, non-HTML based
forms of XML content, such as XSL:FO rendering to PDF files,
client-dependent transformations such as WML-formatting for
WAP-enabled devices, or direct XML serving to XML and XSL aware
clients.
[0492] The platform 808 divides the development of web content into
three separate levels: (a) XML creation--The XML file is created by
the content owners. They do not require specific knowledge on how
the XML content is further processed--they only need to know about
the particular chosen "DTD" or tagset for their stage in the
process. This layer can be performed by users directly, through
normal teeditors or XML-aware tools/editors; (b) XML
processing--The requested XML file is processed and the logic
contained in its logicsheet is applied. Unlike other dynamic
content generators, the logic is separated from the content file;
and (c) XSL rendering--The created document is then rendered by
applying an XSL stylesheet to it and formatting it to the specified
resource type (HTML, PDF, XML, WML, XHTML, etc.).
Dynamic Web Content Development Using Web Content Server 800
[0493] The Web Content Server 800 can be based on XML, XSLT and
Java technologies. Using these technologies, the Web Content Server
800 allows for easier user interface customization, more
flexibility in page functionality, easier page maintenance and the
creation of more easily reusable code. It encourages the separation
of data production, interaction elements and display information by
separating different aspect of page production in different
files.
[0494] Using platform 808, developing a web page (web content)
requires the development of the following components: (a) a control
file; (b) a model file; (c) a view file; and (d) Command Managers
and Commands.
[0495] The Model contains all the data and interactivity for a
given page. Users are responsible for generating an XML page
containing the raw data they wish to display, independent of the
appearance of that data or any additional presentation
information.
[0496] The Model can be implemented using a dynamic page engine
(JSPs or XSPs). In addition, API 808 provides a variety of helper
tagsets to automate common scripting operations, minimizing the
amount of custom scripting required by a user.
[0497] Model Developers are typically Java programmers, since the
bulk of development effort is implementing a companion Java Bean
that invokes the appropriate SABA Manager API. They then use the
dynamic features of the engine (tag libraries and Java scripts) to
place data from the bean onto the page.
[0498] The View contains all style and presentation for a given
page. Users are responsible for implementing an XSLT stylesheet
that transforms the model into a specific presentation environment.
View developers are typically UI designers, since the bulk of
authoring effort is crafting the HTML for a static page, then
adding in the set of XSLT tags to create a stylesheet for the
associated model page.
[0499] Widgets are a set of predefined UI components and
presentation elements common to web applications. Widgets can have
user interactivity (fields, links) or be presentation only
(images). Widgets can be implemented as XSLT stylesheets. The
platform 808 includes a predefined set of common widgets that can
be used by both model and view developers. Note also that
developers have the option of overriding the default widgets to
provide enhanced or custom functionality if required.
[0500] The important distinction between tag libraries and widgets
is that tag libraries are used in the model and are an aid to
dynamic content generation, whereas widgets are used in the
transform step and are an aid to end-content generation. Tag
libraries can be implemented in Java, whereas widgets are
preferably implemented as stylesheets.
[0501] FIG. 8B shows how the engine 808 processes/uses these files
to produce dynamic web content.
[0502] The process of creating the HTML to send to the browser
begins with reading the control file, 860. The control file 862 is
simply a file that identifies the model file 864, the view file 866
and the widget library 868 to use to produce the final HTML result
870. The control file 862 also contains link transformation
information that is used to transform links used in the model file
864. This link transformation is used to map model-file hyperlink
references contained in the model file 864 to appropriate control
file names.
[0503] The model file 864 is loaded and preprocessed based on the
information contained in the control file 862. The preprocessed
model file is executed in three steps. In 872, any tags from the
tag library are processed. The tag library includes tags for
internationalization, command invocation and widget management. In
874, the resulting XML file is then further processed to generate a
Java class. In 876, the Java class is executed to produce the model
instance 878. The model instance 878 contains all data and other
information needed for display. For example, the model instance 878
will contain the XML form of the data retrieved by the Commands
invoked in the model page and it will contain all internationalized
labels and widgets. In 880, the model instance 878 is first
transformed using the widget library 868. In 882, the result of the
widget transformation is then further transformed using the view
transformation file 866 to produce the final result 870.
[0504] The process outlined above also highlights how the different
aspects of developing dynamic web content are separated. The design
of a particular web page is the result of answering the following
questions: (a) What do I do with parameters sent from the browser
and what data is needed to display the page? How do I perform these
tasks? (b) How will the user interact with the page? What buttons,
entry fields etc. will the user have? and (c) How are the data and
the interaction elements displayed on the page?
[0505] The answer to question (a) results in the model page and the
Command objects used by the model page. The model page invokes all
needed Commands to perform the tasks of the page and to produce the
data needed for display. The answer to question (b) produces a
listing of all widgets and their linkages to the data being
displayed. Although this list is part of the model page, the list
of widgets and their linkages are all declared in a clearly
identifiable part of the page. Finally, the answer to question (c)
produces the view transformation page.
Page Development Process
[0506] Typically the page development process starts with an HTML
mockup of the page. The Web Content Server 800 development process
can start with the HTML mockup as well. However, users do not
modify this mockup to include code. Instead the process illustrated
in FIG. 8C is followed.
[0507] As illustrated in FIG. 8C, using the HTML mockup 884, the
user develops three specifications. The data model specification
886 is developed to meet three basic criteria. First, the data
model needs to contain enough information to drive the interface.
For example, if the interface needs to display the name of an
object, then the data model must contain the object name in some
form. Second, the data model specification should maximize reuse of
command objects. For example, if a command object already exists
that can retrieve a needed object in a serialized XML format, then
the data model of the command object should be reused instead of
reinventing a new XML representation of the same object. Finally,
the data model specification should be generic so other pages can
reuse the model generation components (Commands). How general the
data model should be is determined by balancing the trade-off
between performance (since producing more data may incur
performance penalty) and reusability. If producing a more general
data model causes high performance penalty, then a less general
solution may be better. On the other hand, if adding a few not
needed items comes at no or little performance cost, then the more
general data model is preferred. For example, objects implementing
the IXMLObject interface will typically provide more than enough
information about themselves. The data model specification 886
should essentially be a sample of the data returned by the Command
objects and the specification XML should be wrapped in tags.
[0508] The widget specification 888 is a list of widgets needed by
the page. These widgets include input fields of all types
(textboxes, radio button collections, check box collections,
dropdown lists, hyperlink buttons, etc.). Besides declaring what
widgets the page needs, the specification 888 can also include how
these widgets relate to the data model. For example, the page may
require an edit button widget for every object it displays. The
widget specification 888 can therefore indicate that the edit
button is "attached to" those objects. The widget specification 888
can be very incomplete, because users (such as view developers)
will typically only need the name of the widget for layout
purposes. The widget library will take care of rendering the widget
itself.
[0509] The third specification is the specification of
internationalized items 890 (labels, graphics). The specification
890 includes a list of all labels and images used on the page. The
specification 890 contains just the name of the label and some
sample text for the label.
[0510] Once the specifications 886, 888, and 890 are complete, the
user or a tool, produces a sample model instance 892. The user can
use the model instance 892 to test the view stylesheet (by using
any standard XSLT tool). The user develops the view stylesheet by
converting the original HTML mockup to an XSLT stylesheet to
retrieve dynamic data, widgets and internationalized labels from
the model instance. This conversion process can mostly be done in
an HTML editor.
Customizing/Modifying a Page
[0511] One of the benefits of using the platform 808 for page
development is in the ease of page customization and page
modification. Often the look and feel of pages needs to be modified
after the initial design. Using conventional systems this process
was very painful: individual pages had to be revisited by software
engineers and tweaked to confirm to the new requirements. These new
requirements often meant changed look of textual/graphical
information (e.g., justification of text, font, color), changing
the layout (e.g., adding another Save button to the bottom of the
page, moving buttons and table columns around), or adding/removing
information content (e.g., display the price of an offering but
don't display the description of the offering). Also, often changes
are required across pages: e.g., we want every link button to use
"Helvetica" instead of "Verdana" for its label, and the alt label
for the link image should be the same as the label of the link
itself. Sometimes page changes include adding new interaction
components, e.g. adding a "Cancel" button to the page, or adding an
edit button next to each displayed object. Such changes are much
simpler to perform using Web Content Server 800.
Modifying Text/Graphics Look and Feel
[0512] To change the look and feel of textual and graphical
information, the user can edit the view page in an HTML tool. The
user can add <span>, <div> etc. tags around the
components needed modification, and define the "style" attribute to
reflect the desired look and feel changes. If the user needs to
develop for browsers with limited CSS support (e.g., Netscape 4.x),
the user can wrap the components in <u>, <b>,
<font>, etc. tags as needed.
Layout Changes
[0513] The cut/copy/paste commands of the HTML editor can be used
to perform most layout changes requiring the repositioning of
different components. Dreamweaver, for example, gives users
powerful HTML/XML element selection capabilities that make it
easier to move and copy whole HTML/XML document fragments.
Adding/Removing Information Content
[0514] Often the model specification will result in the production
of more content than needed by a particular view. For example, the
model for a page that needs to display the parents of a particular
security domain only may also produce other information about the
security domain (e.g., the description of the domain). This is
especially likely when the model page reuses other, already
existing command objects. In such cases displaying additional
content can simply be done at the view page level: the user needs
to place the newly required information somewhere on the view page.
Removing information items is also very simple, since users can
simply delete a particular HTML/XML fragment if viewing that piece
of the model is not needed.
Changing Look and Feel of Widgets Globally
[0515] The use of widget libraries make it very simple to change
the look and feel of widgets across pages. Either the widget
transformation of the used widget library can be changed or an
alternative widget library can be developed. In the latter case
control pages must be updated to point to the new instead of the
original widget library.
Adding New Interaction Components
[0516] If the guidelines for model page design are followed then
adding new interaction components (e.g., buttons) is a very simple
task. Adding a new widget (e.g., Cancel button) means adding a new
widget to the widget section of the model page AND changing the
view page to include the new widget. Since the widget section is a
separate section of the model page, software engineers (and perhaps
UI engineers) can make the required change without
disturbing/interfering with any other part of the model page.
Components of the Platform 808
[0517] The control page associates a particular model page, view
page and widget library.
[0518] The model page produces the data needed for displaying the
page and it also defines the widgets (interaction elements, such as
links, buttons, input fields, etc.) and internationalized resources
(labels, graphics) used by the view page. The model page has a well
defined structure. Model pages can produce XML representation of
data using command managers and command objects. A model page can
invoke a command using a tag. After the model page is executed, the
tag will be replaced with the XML data produced by the selected
Command.
[0519] The model instance is the XML document produced by executing
the model page.
[0520] The view page displays the data and widgets contained in the
model instance (i.e. the XML document produced by executing the
model page). If the control page declares a widget library to use,
then the view transformation takes place after the widgets have
already been transformed to the appropriate format (e.g. HTML).
[0521] The widget library contains the display transformation for
widget components. After the model page executes the produced
widgets are transformed to the appropriate output format (e.g.,
HTML). The resulting HTML markup is wrapped in tags so the view
transformation page can easily identify and place each widget.
[0522] The tag library contains tags users can use in their model
pages to access common code functionality. This common
functionality includes accessing resource bundles, retrieving page
parameters, executing commands, declaring widgets, etc.
Control Page
[0523] The entry point into any platform 808 page is an XML
document that serves as a controller. This page is simply an XML
document that points to the model, view, and widget documents. This
convention creates a clean decoupling between the three constituent
pages. As an example of the benefit of this approach, web content
administrators may substitute a different control page in a
deployment environment; this allows them to use the same model
while modifying just the view.
Coding Guidelines
[0524] Pages built using the platform 808 employ certain
conventions and coding guidelines to ensure consistent operation
and simplify some processing steps. These coding guidelines include
the following:
[0525] a. Head Element
[0526] All model pages must contain a head page element that
defines some information specific to the model. It is used to
capture the following:
[0527] required metadata about input and pass-through
parameters
[0528] values of i18n labels. The convention is that all i18n
values are obtained via the i18n utility tag in the model page;
this information is then passed on to the stylesheet in a
predetermined location within the wdk:head element page title and
other useful information about the page.
[0529] b. Widget Stylesheet
[0530] The widget stylesheet is simply a list of xsl:includes of
the widgets used on this page. The widgets can be from the set of
predefined widgets or can be customized widgets.
One Example of a Preferred Embodiment
[0531] In one preferred embodiment, the Web Content Server 800 is a
dynamic content generation framework based on the apache Cocoon
project. Like other approaches, such as JSP, ASP, ColdFusion etc.,
the Web Content Server 800 would allow developers to create web
pages to display data derived dynamically through some business
logic. Unlike other dynamic content generation frameworks, the Web
Content Server 800 separates the content from its presentation.
This separation makes it easier to customize pages, to provide
different versions of pages to different user agents (desktop
browsers, handheld devices, etc.).
[0532] Content production and presentation separation is achieved
by following a Model-View-Widget (MVW) paradigm. In this paradigm
three distinct components are responsible for generating the final
output sent to the client (desktop browser, WAP phone, handheld
device). The model page is responsible for producing the content as
well as the user interaction components (widgets). Widget look and
behaviors are added during the widget transformation. Finally the
View transformation provides the look and layout for the content
and widgets produced by the model page.
File Loading Algorithm
[0533] When the Cocoon engine processes the HTTP request, it
invokes the getDocument( ) method of the file producer registered
with Cocoon. Web Content Server 800 uses a specific file producer
(SabaProducerFromFile) to load the requested file. This file
producer uses SabaSite properties to determine the location of the
requested file. To register the Web Content Server 800 specific
file producer, the following line is added to
cocoon.properties:
[0534]
producer.type.file=com.saba.web.engine.SabaProducerFromFile
SabaSite
[0535] SabaSite is an object containing a set of properties
relevant to a particular saba application. These properties
include, but are not limited to:
[0536] File system location of application pages
[0537] File system location of images
[0538] Name of the site
[0539] Name of the servlet driving this application
[0540] Etc.
[0541] Using the SabaSite object and the associated property file
the configuration of a given Saba application can be changed with
ease.
The Algorithm
[0542] The SabaProducerFromFile uses the request URL to identify
the file requested. The getDocument method of this class performs
the following steps: [0543] 1. Determines the SabaSite based on the
request. The SabaSite is identified as follows: [0544] a. Extract
the servlet path information from the request object using the
HttpServletRequest API (getServletPath( )). [0545] b. If the
servlet path ends with a Web Content Server 800 specific string
suffix, then the associated SabaSite name is determined by
stripping of that suffix. [0546] c. If the servlet path does not
end with the Web Content Server 800 specific string suffix, then
the system default SabaSite name is retrieved using the SabaSite
API. [0547] d. The SabaSite is retrieved using the SabaSite API
[0548] e. Finally the SabaSite is initialized using the request
object [0549] 2. Uses the SabaSite object to determine the location
of all web documents by getting the document root property of the
site. [0550] a. Uses the SabaSite API to retrieve the document root
(getDocumentRoot( )). [0551] 3. Determines the relative pathname of
the requested document from the request object. [0552] a. Uses the
HttpServletRequest getPathInfo( ) API. [0553] 4. Computes the
absolute path of the document by combining the document root with
the relative pathname. [0554] a. Appends the value of the document
root and the relative pathname. [0555] b. Replaces all "\"
characters with "/" to make sure the absolute pathname has the
correct syntax. [0556] 5. Parses the file identified by the
pathname and returns the resulting document object model (DOM).
ControlFile Processing Algorithm
[0557] When a client sends a request to a Web Content Server 800
application, the above-described process is used to identify and
parse the control file. The control file is an RDF document that
ties the above-mentioned three components of the Model-View-Widget
paradigm together.
Control File Example
TABLE-US-00051 [0558] 1 <?xml version="1.0"
encoding="UTF-8"?> 2 <?cocoon-process type="wdk"?> 3
<!DOCTYPE rdf:RDF SYSTEM "../control10.dtd"> 4 <rdf:RDF
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:wdk="http://www.saba.com/XML/WDK"> 5 <rdf:Description
id="searchPerson"> 6 <rdf:type
resource="http://www.saba.com/XML/WDK/ Control"/> 7
<wdk:version>1.0</wdk:version> 8 <wdk:model
rdf:resource="searchPerson.xml"/> 9 <wdk:view
rdf:resource="searchPerson.xsl"/> 10 <wdk:widgets
rdf:resource="../xsl/widget/wdk_widgets.xsl"/> 11
<wdk:links> 12 <wdk:link model="searchPerson.xml"
control="searchPerson.rdf"/> 13 </wdk:links> 14
</rdf:Description> 15 </rdf:RDF>
[0559] The control file contains a Cocoon processing instruction
(line 2) that is parsed by the Cocoon engine. The cocoon engine
uses the processing instruction to look-up the processor it needs
to use to process the document. The Web Content Server 800
installation contains the following entry in the cocoon.properties
file:
[0560]
processor.type.wdk=com.saba.web.engine.ControlFileProcessor
[0561] This line tells the cocoon engine that the
com.saba.web.engine.ControlFileProcessor java class is responsible
for processing all documents that contain a cocoon processing
instruction of type="wdk".
[0562] The control file processor performs the following steps:
[0563] 1. Identifies the model, view and widget files. [0564] 2.
Parses the model file and creates a DOM representation of the XML
document. [0565] 3. Inserts in the model file DOM: [0566] Cocoon
processing instruction to invoke the Web Content Server 800
transformer after the model page is executed. The Web Content
Server 800 transformer is responsible for transforming the result
of the model page using the widget and then the view XSL
stylesheets. [0567] XSLT processing instructions to declare where
the widget and view transformation stylesheets are located. This
information was extracted from the control file in step 1. [0568]
4. Updates hyperlinks in the model file based link mapping
information found in the control file.
[0569] The control file processor returns the document object model
containing all these updates, and the Web Content Server 800 engine
then processes this DOM.
Identifying Model, View and Widget File
[0570] The control file contains the following three properties for
encoding the three files:
[0571] wdk:model: the rdf:resource attribute of this property is
the path to the model file. (See line 8 in the example above.)
[0572] wdk:view: the rdf:resource attribute of this property is the
path to the view file. (See line 9 in the example above.)
[0573] wdk:widget: the rdf:resource attribute of this property is
the path to the widget file. (See line 10 in the example
above.)
Creating the DOM for the Model Document
[0574] Given the path information in the rdf:resource attribute of
the wdk:model property, the actual path is computed based on saba
site information. The process of computing the path is almost
identical to the process described under the File Loading Algorithm
section. The only difference is that if the value of rdf:resource
does not begin with the path delimiter character ("/") then the
processor interprets the path as a relative path from the control
file. Once the path is computed, the model file is parsed and a DOM
representation is generated.
Updating the Model DOM
[0575] Before the model page (its DOM representation) can be
further processed by the wdk engine, a cocoon processing
instruction <?cocoon-process type="xsp"?> is inserted. This
processing instruction instructs the engine to first process the
model page using the xsp processor (see section below on Custom XSP
Processor). The control file processor inserts another processing
instruction: <?cocoon-process type="wdk_xsl"?>. This
processing instruction directs the Cocoon engine to use the Web
Content Server 800 specific XSLT transformer for the transforming
steps (see section below on custom XSLT processor). Furthermore,
two <?xml:stylesheet . . . ?> processing instructions are
also inserted in the document object model following the above
processing instruction. The "href" data component of these
instructions identifies the widget and view stylesheets in that
order. The Web Content Server 800 specific XSLT transformer will
process these two processing instructions to perform the XSL
transformations.
[0576] The following Java code shows how the processing
instructions are inserted into the DOM:
TABLE-US-00052 private void insertNextPI(Document doc,
ProcessingInstruction pi) throws ProcessorException { try {
NodeList nodeList = doc.getChildNodes( ); Node theNode=null; Node
lastPI=null; // find last PI for (int i=nodeList.getLength( )-1 ; i
>= 0 ; i--) { theNode = nodeList.item(i); if
(theNode.getNodeType( ) == Node.PROCESSING_INSTRUCTION_NODE){
lastPI=theNode; break; } } if (lastPI==null) { // cound not find a
PI so just get the first node theNode=nodeList.item(0); } else {
//going to do an insertBefore, so we want to move to the next
//node so that this new PI gets inserted AFTER the last PI
theNode=lastPI.getNextSibling( ); if (theNode==null) { //should
always have at least a root node after a PI throw new
ProcessorException("Error processing control file: need a root node
after a processing instruction"); } } // if lastPI==null
doc.insertBefore((Node) pi, theNode); } catch (DOMException e) {
throw new ProcessorException("Unexpected error processing control
file: " + e.toString( )); } } /* insertNextPI */
Updating Link Information
[0577] Model pages typically contain links that allow the model
page to invoke another page. In order to make model pages reusable
with different view pages, page references in a model page always
refer to other model pages. This way different control files can
reuse the same model page but use two different view pages.
However, links pointing to model pages have to be transformed to
control page hyperlinks before the final document is produced,
since the request URL has to contain information about the control
file and not the model file. In order to perform this
transformation, the control file contains information about how to
map a model page reference to a control page reference. The control
file contains a single wdk:links element, which contains a number
of wdk:link elements. Each wdk:link element has two attributes:
model and control. The model attribute is the hyperlink name of a
model file, while the value of the control attribute is the
hyperlink name of the control file.
[0578] The control file processor locates the wdk:link and
wdk:links elements in the control file DOM using the standard DOM
API. Once all wdk:links elements are located, the control file
processor inserts a wdk:linkMap element in the wdk:head element of
the model DOM, and then inserts one wdk:linkMapEntry for each
wdk:link found in the control file using the DOM API. The
wdk:linkMapEntry element has the same attributes as the
corresponding wdk:link in the control file. This way the mapping
information is made available in the model page, and can be used by
either the model page itself or the subsequent widget and view
transformations. For example, the wdk:link widget makes use of this
information to transform model page references to control page
URLs.
Example
The Model DOM Before and after the ControlFileProcessor
[0579] The following code sample shows the XML serialized version
of a model file before the ControlFileProcessor updated the
DOM.
TABLE-US-00053 <?xml version="1.0"?> <xsp:page
language="java" xmlns:xsp="http://www.apache.org/1999/XSP/Core"
xmlns:wdktags="http://www.saba.com/XML/WDK/taglib">
<xsp:structure>
<xsp:include>com.saba.exception.*</xsp:include> ...
</xsp:structure> <wdk:page
xmlns:wdk="http://www.saba.com/XML/WDK"> <wdk:head>
<wdktags:in> <wdktags:param name="sessionKey"/>
<wdktags:param name="actionKey" required="false" type="String"
default=""/> <wdktags:param name="personSearch"/>
</wdktags:in> <wdktags:out> <wdk:param
name="sessionKey" type="String" required="true"/> <wdk:param
name="actionKey" type="String" required="false"/> <wdk:param
name="personSearch" type="String" required="true"/>
</wdktags:out> <xsp:logic> Session sabaSession =
SessionManager.getSession(sessionKey); String desiredLang =
(String)sabaSession.getBlob("selectedLanguage"); </xsp:logic>
<wdktags:i18n.load resource="party_labels">
<language><xsp:expr>desiredLang</xsp:expr></langu-
age> </wdktags:i18n.load>
<wdk:title><wdktags:i18n.label
name="kl18n6000SearchForPeopleLabel"/> </wdk:title>
<wdk:labels> <wdk:label
name="busUnitLabel"><wdktags:i18n.label
name="kl18n6008BusinessUnitLabel"/></wdk:label>
<wdk:label name="locLabel"><wdktags:i18n.label
name="kl18n6000LocationLabel"/></wdk:label> <wdk:label
name="firstNameLabel"><wdktags:i18n.label
name="kl18n6000RegularFirstNameLabel"/></wdk:label>
<wdk:label name="lastNameLabel"><wdktags:i18n.label
name="kl18n6000RegularLastNameLabel"/></wdk:label>
<wdk:label name="locationLabel"><wdktags:i18n.label
name="kl18n6000RegularLocationLabel"/></wdk:label>
</wdk:labels> </wdk:head> <wdk:form method="GET">
<wdk:hidden_field> <name>sessionKey</name>
<value><xsp:expr>sessionKey</xsp:expr></value>
</wdk:hidden_field> <wdk:hidden_field>
<name>actionKey</name>
<value>search</value> </wdk:hidden_field>
<wdk:model> <xsp:logic> if (actionKey.equals("search"))
{ <people> <wdktags:execute
manager="com.saba.client.party.beans.PersonCommandManager"
command="searchForPeople" argument="personSearch"/>
</people> } /* if actionKey.equals("search")*/
</xsp:logic> </wdk:model> </wdk:form>
<wdk:widgets> <wdk:input name="lastNameField">
<label><wdktags:i18n.label
name="kl18n6000LastNameLabel"/></label>
<id>personSearch</id>
<value><xsp:expr>personSearch</xsp:expr></value&g-
t; </wdk:input> <wdk:link name="go">
<id>GO</id> <href>searchPerson.xml</href>
<type>button</type> <label><wdktags:i18n.label
name="kl18n6XXXXXGO"/></label>
<prompt><wdktags:i18n.label
name="kl18n6XXXXXGO"/></prompt> </wdk:link>
</wdk:widgets> </wdk:page> </xsp:page>
[0580] The following code sample shows the same model file after
the ControlFileProcessor updated the model file. The changes are
shown in bold face:
TABLE-US-00054 <?xml version=''1.0''?> <?cocoon-process
type=''xsp''?> <?cocoon-process type=''wdk_xsl''?>
<?xml:stylesheet href="../xsl/widget/wdk_widgets.xsl"?>
<?xml:stylesheet href="searchPerson.xsl"?> <xsp:page
language=''java'' xmlns:xsp=''http://www.apache.org/1999/XSP/Core''
xmlns:wdktags=''http://www.saba.com/XML/WDK/taglib''>
<xsp:structure>
<xsp:include>com.saba.exception.*</xsp:include> ...
</xsp:structure> <wdk:page
xmlns:wdk=''http://www.saba.com/XML/WDK''> <wdk:head>
<wdktags:in> <wdktags:param name=''sessionKey''/>
<wdktags:param name=''actionKey'' required=''false''
type=''String'' default=''''/> <wdktags:param
name=''personSearch''/> </wdktags:in> <wdktags:out>
<wdk:param name=''sessionKey'' type=''String''
required=''true''/> <wdk:param name=''actionKey''
type=''String'' required=''false''/> <wdk:param
name=''personSearch'' type=''String'' required=''true''/>
</wdktags:out> <xsp:logic> Session sabaSession =
SessionManager.getSession(sessionKey); String desiredLang =
(String)sabaSession.getBlob(''selectedLanguage'');
</xsp:logic> <wdktags:i18n.load
resource=''party_labels''>
<language><xsp:expr>desiredLang</xsp:expr></langu-
age> </wdktags:i18n.load>
<wdk:title><wdktags:i18n.label
name=''kl18n6000SearchForPeopleLabel''/> </wdk:title>
<wdk:labels> <wdk:label
name=''busUnitLabel''><wdktags:i18n.label
name=''kl18n6008BusinessUnitLabel''/></wdk:label>
<wdk:label name=''locLabel''><wdktags:i18n.label
name=''kl18n6000LocationLabel''/></wdk:label>
<wdk:label name=''firstNameLabel''><wdktags:i18n.label
name=''kl18n6000RegularFirstNameLabel''/></wdk:label>
<wdk:label name=''lastNameLabel''><wdktags:i18n.label
name=''kl18n6000RegularLastNameLabel''/></wdk:label>
<wdk:label name=''locationLabel''><wdktags:i18n.label
name=''kl18n6000RegularLocationLabel''/></wdk:label>
</wdk:labels> <wdk:linkMap> <wdk:linkMapEntry
model="searchPerson.xml" control="searchPerson.rdf"/>
</wdk:linkMap> </wdk:head> <wdk:form
method=''GET''> <wdk:hidden_field>
<name>sessionKey</name>
<value><xsp:expr>sessionKey</xsp:expr></value>
</wdk:hidden_field> <wdk:hidden_field>
<name>actionKey</name>
<value>search</value> </wdk:hidden_field>
<wdk:model> <xsp:logic> if
(actionKey.equals(''search'')) { <people> <wdktags:execute
manager=''com.saba.client.party.beans.PersonCommandManager''
command=''searchForPeople'' argument=''personSearch''/>
</people> } /* if actionKey.equals(''search'')*/
</xsp:logic> </wdk:model> </wdk:form>
<wdk:widgets> <wdk:input name=''lastNameField''>
<label><wdktags:i18n.label
name=''kl18n6000LastNameLabel''/></label>
<id>personSearch</id>
<value><xsp:expr>personSearch</xsp:expr></value&g-
t; </wdk:input> <wdk:link name=''go''>
<id>GO</id> <href>searchPerson.xml</href>
<type>button</type> <label><wdktags:i18n.label
name=''kl18n6XXXXXGO''/></label>
<prompt><wdktags:i18n.label
name=''kl18n6XXXXXGO''/></prompt> </wdk:link>
</wdk:widgets> </wdk:page> </xsp:page>
[0581] Custom XSP Processor
[0582] Instead of using the XSP processor of Cocoon, Web Content
Server 800 uses a custom XSP processor. To make this happen, the
following line is added to the cocoon.properties file:
TABLE-US-00055 processor.type.xsp =
com.saba.web.engine.SabaXSPProcessor
[0583] This processor adds the following capabilities: [0584]
Debugging: The Web Content Server 800 XSP processor can produce
intermediate files representing the documents as the model page is
transformed from its original form to the java code that is
executed and the actual data that is produced by the java code.
These intermediate files can be inspected to locate the source of a
problem more easily. [0585] Cache control: For debugging purposes
it is important to know that the code that executes is the code
that the developer has just edited. However, the cocoon engine
contains a number of caching mechanisms that make this assumption
incorrect sometimes (ie. The code that's executed is code that is
in the cache instead of code that the developer has just changed).
The Web Content Server 800 XSP processor allows control over
caching.
Producing Intermediate Files for Debugging Purposes
[0586] The SabaXSPProcessor can produce intermediate files as the
model file goes through the different transformation steps. The
helper classes XSPDebugger and DebuggerConfig are used to control
which if any intermediate files should be produced. The following
properties are introduced in cocoon.properties for controlling
debugging behavior:
[0587] wdkdebugoutput
[0588] wdkdisablecache
[0589] wdkdebug
[0590] The wdkdebug property can have the following values:
[0591] off: No debugging information is produced
[0592] full: Every intermediate file is produced
[0593] wdktags: Only the result of the wdk tag library
transformation is output
[0594] wdk: Only the result of the widget library transformation is
output
[0595] xsp: Only the result of the xsp transformation is
output.
[0596] model: Outputs the result of executing the java code
produced from the model page.
[0597] The wdkdebugoutput property can have the following
values:
[0598] sourcedir: The output files are placed in the same directory
where the source documents are read from.
[0599] browser: The output files are sent to the browser
[0600] repository: The output files are placed in the cocoon
repository directory.
[0601] The wdkdisablecache can either be "true" or "false". If true
the cocoon cache is not used.
[0602] The init method of the SabaXSPProcessor creates an instance
of the DebuggerConfig class, and the process method creates an
instance of XSPDebugger. The XSPDebugger is a subclass of Debugger
and it uses the DebuggerConfig object to read the debugger
configuration from the cocoon.properties file.
The Debugger and XSPDebugger Classes
[0603] The Debugger has the following API:
TABLE-US-00056 public void readParameters(Dictionary parameters,
DebuggerConfig config);
[0604] This method initializes the Debugger with the current
debugging property values.
[0605] protected boolean debugThis(String rule); [0606] The method
returns true if the wdkdebug property is either "full" or matches
the rule parameter.
[0607] protected boolean browserOnly( ); [0608] The method returns
true if the wdkoutput property is set to "browser".
[0609] public boolean cacheDisabled( ); [0610] Returns true if the
wdkdisablecache is true.
[0611] The XSPDebugger introduces the following methods:
[0612] public boolean debugLogicsheet(String rule, Document
document); [0613] Returns true if Debugger.debugThis(rule) is true
AND if Debugger.browserOnly( ) is true. If only
Debugger.debugThis(rule) is true, then first saves the intermediate
result before returning false.
[0614] public void debugFinalXSP(Document document) [0615] If the
wdkdebug property is full or set to model then the result of
executing the code produced from the model file is output.
Custom XSLT Processor
[0616] The default XSLT processor that comes with Cocoon performs a
single XSLT transformation only. However, Web Content Server 800
requires two XSL transformations after the java code produces the
data. The first transformation replaces the widgets with their HTML
representation (the widget transformation) while the second
transformation renders the data (the view transformation). To make
the engine aware of the Web Content Server 800 XSLT processor, the
following line is added to the cocoon.properties file:
[0617]
processor.type.wdk_xsl=com.saba.web.engine.WDK_XSLTProcessor
[0618] The Web Content Server 800 XSLT processor takes as input the
document object model produced by executing the XSP page. The
processor extracts the xml:stylesheet processing instructions from
the DOM, and executes XSL transformations using the stylesheet
documents referred to by the "href" data element in the processing
instructions. (The xml:stylesheet processing instructions were
inserted in the source document by the control file processor--see
the ControlFileProcessor algorithm section for details). After each
transformation step, if the debugger flags are set, the DOM is
serialized and saved to a text file.
[0619] The following code snippet shows how the widget and view
transformations are performed:
TABLE-US-00057 try { /* get all stylesheets referred to by this
document */ Vector resources = getResources(document, request,
context); /* apply each stylesheet in turn */ Enumeration e =
resources.elements( ); while (e.hasMoreElements( )) { Object
resource = e.nextElement( ); this.logger.log(this, "Processing
stylesheet " + resource.toString( ), Logger.DEBUG); Document
stylesheet = getStylesheet(resource, request,
!xsltDebugger.cacheDisabled( )); Document result =
this.parser.createEmptyDocument( ); document =
transformer.transform(document, null, stylesheet,
resource.toString( ), result, params); if
(xsltDebugger.debugStylesheet(document, resource)) { // requested
debug output to browser, so done now return document; } } return
document; } catch (PINotFoundException e) { return document; }
Custom XSP Page Class
[0620] Each XSP page (model page) is transformed to a java object
(source code generated, compiled and the class is loaded). In Web
Content Server 800 the generated java objects are instances of the
SabaXSPPage class, which is a subclass of the XSPPage class. (The
XSPPage class is the default class provided by Cocoon.) In order to
change the class from XSPPage to SabaXSPPage, the following changes
had to be made: [0621] 1. Create a new xsp-java.xsl taglibrary
stylesheet based on the default stylesheet that comes with Cocoon:
[0622] a. Change the class declaration line to extend SabaXSPPage
instead of XSPPage as follows: [0623] public class <xsl:value-of
select="@name"/> extends SabaXSPPage { [0624] b. Invoke the
initialization method specific to SabaXSPPage in the
populateDocument method: [0625] initializeOnRequest(request,
response); [0626] This method initializes protected site and logger
variables. (See below) [0627] 2. Change the cocoon.properties file
by adding the following line:
processor.xsp.java.logicsheet=/com/saba/web/engine/xsp-java.xsl
[0628] The SabaXSPPage class provides model pages access to
frequently needed information including: [0629] Site: information
about the SabaSite object representing the current saba site.
[0630] Path information: extracted from the Saba site object for
convenience [0631] Access to a logger for debugging and status
messages
[0632] SabaXSPPage declares protected member variables for
each:
TABLE-US-00058 protected SabaSite wdkSite; protected Logger
wdkLogger; protected String wdkBaseURL; protected String
wdkRoot;
[0633] These variables are therefore accessible by model pages and
by the tags defined in the wdktags tag library.
Structure of Model Pages
[0634] Model pages are Extensible Server Page (XSP) pages. XSP
pages can contain a mix of static content and content generating
programming logic by using xsp directives (tags) defined in the xsp
tag library. Furthermore, an XSP page can make use of an indefinite
number of application specific tag libraries. A Web Content Server
800 model page uses the wdktags tag library to simplify certain
common programming tasks.
[0635] Web Content Server 800 model pages have a very well defined
structure. The document element of the page is <xsp:page>.
The document element can contain <xsp:structure> and other
xsp directives, but it can contain a single non-xsp element only.
For a Web Content Server 800 page that element is wdk:page. The
wdk:page element consists of the following subsections: [0636]
wdk:head--contains internationalized labels, the page title, image
references, link mapping information (generated automatically from
the control file by the control file processor). [0637]
wdk:form--The wdk:form element is one of the elements in the widget
library. Since most wdk pages are HTML forms, the wdk:form element
is used to generate the HTML form and javascript functions required
by a Web Content Server 800 application. For example, a javascript
function is generated that can be called by link widgets to submit
the form. [0638] wdk:widgets--widgets (input fields, buttons,
hyperlinks, etc.) are all listed in the wdk:widgets section.
[0639] The wdk:form element can contain the declaration of hidden
fields needed by the application, and it contains a singe wdk:model
element. The wdk:model element contains all "data" generated by the
page.
[0640] Often all the wdk:model section contains is invocations of
Commands that produce the appropriate XML content.
Separating Content from Interaction
[0641] An important property of model pages is the ability to
generate/declare dynamic content (through commands) and interaction
elements (widgets) independently of each other. This separation of
content and widget generation allows for greater reusability.
However, at the end of all the processing, the widgets and the
content have to be combined. For example, an input text field (a
widget) and the "name" property of a business object have to be
connected/combined some way to make sure that that particular text
field can display that particular property. This connectivity
between model elements and widgets is achieved by Web Content
Server 800 tag library tags.
[0642] The wdktags:attachTo tag can be used to "attach" (copy) a
particular widget to a model element.
[0643] For example, a software engineer may author the following
simple model document:
TABLE-US-00059 <xsp:page language= "java" xmlns:xsp=
"http://www.apache.org/1999/XSP/Core" xmlns:wdktags=
"http://www.saba.com/XML/WDK/taglib" > <wdk:page>
<wdk:head> </wdk:head> <wdk:form method= "POST">
<wdk:model> <domain> <name>Domain 1</name>
<id>id1</id> </domain> <domain>
<name>Domain 2</name> <id>id2</id>
</domain> </wdk:model> </wdk:form>
<wdk:widgets> <wdk:input name= "editName">
<wdktags:attachTo path= "domain"/>
<value><wdktags:nodeRef path= "name"/></value>
</wdk:input> </wdk:widgets> </wdk:page>
</xsp:page>
[0644] The document resulting from processing the Web Content
Server 800 tag library and the XSP engine execution will be:
TABLE-US-00060 <wdk:page> <wdk:head> </wdk:head>
<wdk:form> <wdk:model> <domain>
<name>Domain 1</name> <id>id1</id>
<wdk:input name= "editName"> <value>Domain
1</value> </wdk:input> </domain> <domain>
<name>Domain 2</name> <id>id2</id>
<wdk:input name= "editName"> <value>Domain
2</value> </wdk:input> </domain>
</wdk:model> </wdk:form> <wdk:widgets/>
</wdk:page>
[0645] Note that the attachTo directive effectively created a copy
of the input widget inside each domain element. Furthermore, the
nodeRef directive has been replaced with the text value of the
element it refers to in its path attribute.
[0646] The following describes the implementation of the attachTo
tag.
TABLE-US-00061 1 <xsl:template match="*[wdktags:attachTo]"> 2
<xsl:variable name="rootNode"> <xsl:choose>
<xsl:when test="wdktags:attachTo/@root"> <xsl:value-of
select="wdktags:attachTo/@root"/></xsl:when>
<xsl:otherwise> WDKDomUtils.getModelNode(xspCurrentNode.-
getOwnerDocument( ).getDocumentElement( )) </xsl:otherwise>
</xsl:choose> </xsl:variable> 3 <xsp:logic> {
List wdkNodes = WDKDomUtils.getNodes((Element)<xsl:value-of
select="$rootNode"/>,"<xsl:value-of select="wdktags:attachTo/
@path"/>"); 4 if (wdkNodes == null) { throw new
RuntimeException("Could not find node: <xsl:value-of
select="wdktags:attachTo/@path"/>"); } Iterator wdklter =
wdkNodes.iterator( ); while (wdklter.hasNext( )) { 5 wdkwidgetNode
= (Node)wdklter.next( ); wdktagsNodeStack.push(xspCurrentNode);
xspCurrentNode = wdkwidgetNode; 6 if (xspCurrentNode == null) {
throw new RuntimeException("Null node in node list"); } 7
<xsp:content> <xsl:copy> <xsl:apply-templates
select="*|@*"/> </xsl:copy> </xsp:content> 8
xspCurrentNode = (Node)wdktagsNodeStack .pop( ); } }
</xsp:logic> </xsl:template>
[0647] Line 1 specifies the match condition: this template will
match any element that contains a wdktags:attachTo sub-element.
Section 2 contains XSL logic for determining what root element
should be used as the starting point for the value of the path
attribute. If the developer specifies a root attribute, then the
value of that attribute is used, otherwise the root element
defaults to the wdk:model node of the model page. Section 3 invokes
the getNodes( ) method on the WDKDomUtils class. That method
returns the set of nodes that can be accessed from the root node
through the path given in the path attribute of the
wdktags:attachTo directive. Section 4 checks for error conditions
and sets up the iteration through the set of DOM elements returned
in section 3. In section 5 the current xsp node (the value of the
xspCurrentNode variable) is saved on a stack, and its value is
replaced with the next node from the set of nodes returned in
section 3. Since the XSP processor uses the xspCurrentNode variable
to mark the current "insertion point"--i.e. the location where the
next DOM node will be inserted in the Document, this operation
effectively copies the current subtree (the widget) to each node
returned in section 3. (Sections 6 and 7 perform the actual
copying.) Finally, section 8 restores the value of the
xspCurrentNode and resumes the iteration.
[0648] The following section describes the implementation of the
nodeRef tag.
TABLE-US-00062 1 <xsl:template match="wdktags:nodeRef"> 2
<xsl:variable name="root"> <xsl:choose> <xsl:when
test="@source"><xsl:value-of select="@source"/>
</xsl:when>
<xsl:otherwise>wdkwidgetNade</xsl:otherwise>
</xsl:choose> </xsl:variable> 3 <xsp:logic>{
Element wdkChildNode = WDKDomUtils.-
getChildNode((Element)<xsl:value-of
select="$root"/>,"<xsl:value-of select="@path"/>");
<xsp:content><xsp:expr>WDKDomUtils.getTextValue
(wdkChildNode)</xsp:expr></xsp:content> }
</xsp:logic> </xsl:template>
[0649] Line 1 specifies the match condition: this rule matches
every nodeRef tag. Section 2 determines the root node: if the
source attribute is given then the value of that attribute is used,
otherwise the value of wdkwidgetNode Java variable is used. The
wdkwidgetNode variable is initialized in the wdktags:attachTo
template described above. This way, if nodeRef is used in the
context of an attachTo tag, the root node is the same node the
widget is copied to. The actual node whose value is needed is
located by following the path from the root node. Finally, the text
value of the node is computed by calling the
WDKDomUtils.getTextValue( ) method.
Structure of View Pages
[0650] View pages are XSLT stylesheets. The role of the view
stylesheet is to convert the XML document produced by executing the
model file (and the subsequent widget transformation) to a format
understood by the user agent. For example, for desktop browsers
this typically means conversion to an HTML representation. Since
model pages have a well-defined structure, view pages are also
highly regular. For example, there are a number of model page
elements that should not be rendered (such as wdk:head element and
its content should not be copied to the output). Other model pages
nodes have a standard representation in HTML (or in the desired
output format). For example, the rule for rendering wdk:page is to
generate the <html> element, the <head> element
containing the <title> element. These common templates are
all grouped in a default stylesheet that can be imported using the
<xsl:import> directive by every view page. As a result, for
simple pages, the view page needs to contain a singe customized
xsl:template rule that matches on the "wdk:model" node. This
template is responsible for rendering the data as well as the
widgets.
Example
Default View Transformation Templates
TABLE-US-00063 [0651] 1 <?xml version="1.0"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.-
org/1999/XSL/Transform" xmlns:wdk="http://www.saba.com/XML/WDK">
<xsl:output method="xml" indent="yes"/> <xsl:strip-space
elements="*"/> 2 <xsl:template match="/"> <xsl:variable
name="titleLabel"><xsl:value-of
select="//wdk:head/wdk:title"/></xsl:variable>
<html> <head> <title><xsl:value-of
select="$titleLabel"/></title> </head> <body>
<xsl:apply-templates/> </body> </html>
</xsl:template> 3 <xsl:template match="* | @*|text(
)|comment( )" priority="-1"> <xsl:copy>
<xsl:apply-templates select="* | @*|text( )|comment( )"/>
</xsl:copy> </xsl:template> 4 <!-- eliminate the
wdk:head element and all children of wdk:widgets -->
<xsl:template match="wdk:head | wdk:widgets">
</xsl:template> 5 <!-- replace widget with span (so we can
do CSS on it) and process their children --> <xsl:template
match="wdk:widget"> <span class="{@name}">
<xsl:apply-templates/> </span> <br/>
</xsl:template> 6 <xsl:template match="wdk:page">
<xsl:apply-templates/> </xsl:template>
</xsl:stylesheet>
[0652] Section 1 defines the namespaces used in the stylesheet.
Section 2 defines the root level template. This template produces
the html tags, and generates the html head element complete with
the title element. Section 3 defines the default template: every
element, attribute, text and comment is copied to the resulting
document, unless a more specific template provides different
instructions. Section 4 specifies a template for eliminating the
wdk:head and wdk:widgets elements and their contents (since the
contents of these tags should not be rendered using the default
template defined in section 3). Section 5 introduces a template for
transforming every widget by wrapping them into a span element
replacing the wdk:widget "wrapper". This makes it possible to use
CSS styling on a per named-widget basis. Finally, section 6 defines
the template for processing the wdk:page element.
A View Page Example
TABLE-US-00064 [0653] 1 <?xml version="1.0"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/
1999/XSL/Transform" xmlns:wdk="http://www.saba.com/XML/WDK"> 2
<xsl:import href="../xsl/view/wdk_defaultview.xsl"/> 3
<xsl:template match="wdk:model"> 4 <h2
align="center"><xsl:value-of select="/wdk:page/
wdk:head/wdk:title"/></h2> 5 <p> <xsl:value-of
select="/wdk:page/wdk:head/wdk:labels/
wdk:label[@name=`nameLabel`]"/> 6 <xsl:for-each
select="parents/parent"> <xsl:value-of select="name"/>
<xsl:text> > </xsl:text> </xsl:for-each>
<xsl:value-of select="parents/leaf/name"/> </p> 7
<xsl:apply-templates select="//wdk:widget"/> 8
</xsl:template> </xsl:stylesheet>
[0654] Section 2 imports the stylesheet containing the default
templates. Line 3 defines the rule for processing the wdk:model
node. Line 4 displays the title of the page by accessing the
wdk:title tag inside the wdk:head tag. Section 6 iterates through
each "parent" element inside the wdk:model element and displays its
name. In section 7 any widget produced by the model page is
displayed.
The wdk Taglibrary
[0655] The wdk taglibrary contains a number of tags to simplify the
development wdk model pages. The tag library includes tags for:
[0656] handling resource bundles for page internationalization,
[0657] invoking commands to generate XML representation of the data
retrieved from the database, [0658] managing the connectivity
between widgets and the produced data model, [0659] managing the
input and output parameters to the model page, [0660] etc.
[0661] To make the tag library accessible by the processing engine,
the following line is inserted in cocoon.properties:
[0662]
processor.xsp.logicsheet.wdktags.java=s:/sys/java/web/com/saba/web/-
xsl/taglib/wdk_taglib.xsl
[0663] The value of the above property identifies the location of
the taglibrary stylesheet. The taglibrary stylesheet contains a
number of xsl:import directives to import templates responsible for
implementing subsets of tags and it also contains a number of
default templates, as the code example below shows:
TABLE-US-00065 <?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:xsp="http://www.apache.org/1999/XSP/Core"
xmlns:wdktags="http://www.saba.com/XML/WDK/taglib"
xmlns:wdk="http://www.saba.com/XML/WDK"> <xsl:preserve-space
elements="*"/> <xsl:include href="wdk_param.xsl"/>
<xsl:include href="wdk_i18n.xsl"/> <xsl:include
href="wdk_command.xsl"/> <xsl:include
href="wdk_control:xsl"/> <xsl:include
href="wdk_site.xsl"/> <xsl:template match="xsp:page">
<xsl:copy> <!-- need to explicity call some logic in the
wdk_command stylesheet --> <xsl:call-template
name="command_header"/> <!-- need to explicity call some
logic in the control stylesheet --> <xsl:call-template
name="control_header"/> <xsl:apply-templates/>
</xsl:copy> </xsl:template> <xsl:template
match="@*|*|text( )|processing-instruction( )|comment( )"
priority="-1"> <xsl:copy> <xsl:apply-templates
select="@*|*|text( )|processing-instruction( )|comment( )"/>
</xsl:copy> </xsl:template> <xsl:template
match="wdk:head"> <xsl:copy> <wdk:site>
<href>/<xsp:expr>wdkRoot</xsp:expr>/</href>
<imageRoot><xsp:expr>wdkSite.getImageRoot(
)</xsp:expr></imageRoot>
<sabaservlet><xsp:expr>WDKSabaUtil.getAssociatedSabaSiteName(w-
dkRoot)</xsp:expr></sabaservlet>
<sitename><xsp:expr>wdkSite.getName(
)</xsp:expr></sitename> </wdk:site>
<xsl:apply-templates/> </xsl:copy>
</xsl:template> </xsl:stylesheet>
An Example
wdktags:param
[0664] The wdktags:param is one of the tags defined in the wdk tag
library. The purpose of this tag is to simplify the extraction of
parameters from the HttpServletRequest object. Traditionally, JSP,
XSP or servlet programmers have to write a number of lines of code
for the parameters they want to process. The code for each
parameter is typically similar to the following:
TABLE-US-00066 String param = request.getParameter("param"); if
(param == null) { param = "some default"; }
[0665] The wdktags:param tag intends to simplify this by allowing
developers to declare what parameters they want to use in the model
page, and the mundane task of extracting the parameter is performed
by the tag itself. Thus, Web Content Server 800 developer can write
the following in the <wdk:head> section of the model
page:
TABLE-US-00067 <wdktags:in> <wdktags:param name= "param"
type= "String" default= "some default" required= "true"/>
</wdktags:in>
[0666] Each parameter can be defined with a single line of XML code
and as a result of this line the developer can use a Java variable
named "param" in their code wherever the value of the "param"
HttpRequest parameter is needed. The wdktags:param tag is
implemented in wdk_param.xsl, and is imported by the main
taglibrary stylesheet. The following code shows the implementation
of wdktags:param:
TABLE-US-00068 1 <?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:xsp="http://www.apache.org/1999/XSP/Core"
xmlns:wdktags="http://www.saba.com/XML/WDK0/taglib"> 2
<xsl:template match="wdktags:in/wdktags:param"> 3
<xsp:logic> <xsl:variable
name="paramName"><xsl:value-of
select="@name"/></xsl:variable> <xsl:variable
name="paramType"> <xsl:choose> <xsl:when
test="not(@type)">String</xsl:when> <xsl:when
test="@type=`ID`">String</xsl:when>
<xsl:otherwise><xsl:value-of
select="@type"/></xsl:otherwise> </xsl:choose>
</xsl:variable> <xsl:variable name="paramRequired">
<xsl:choose> <xsl:when
test="not(@required)">false</xsl:when>
<xsl:otherwise><xsl:value-of
select="@required"/></xsl:otherwise> </xsl:choose>
</xsl:variable> <xsl:variable name="paramDefault">
<xsl:choose> <xsl:when
test="@default=``"><xsl:value-of
select="@default"/></xsl:when> <xsl:when
test="@default=``">""</xsl:when> <xsl:when
test="not(@default) and @type=`String`">""</xsl:when>
<xsl:otherwise>null</xsl:otherwise> </xsl:choose>
</xsl:variable> 4 <xsl:value-of
select="$paramType"/><xsl:text>
</xsl:text><xsl:value-of
select="$paramName"/>=request.getParameter("<xsl:value-of
select="$paramName"/>"); if (<xsl:value-of
select="$paramName"/> == null) <xsl:value-of
select="$paramName"/> = <xsl:value-of
select="$paramDefault"/>; </xsp:logic>
</xsl:template> </xsl:stylesheet>
[0667] Section 1 declares all namespaces used in the stylesheet. In
line 2 the match condition is given for the template. This template
matches on every wdktags:param tag inside a wdktags:in tag. This
nested condition is necessary, because a different template may
transform wdktags:param tags inside the wdktags:out tag. Section 3
computes the values to use for parameter type and parameter default
value. These values are either determined from the values of "type"
and "default" attributes of the wdktags:param tag, or default
values are selected (the java String class for type, and the java
null constant for default). Section 4 produces the java code
declaring the java variable by the name given in the "name"
attribute of the param tag, and the value is initialized either
from the HttpServletRequest object or by using the default value
computed in line 2.
Tags Defined in the Web Content Server 800 Tag Library
[0668] wdktags:param Provides a convenient method for declaring and
using parameters passed in through the HttpServletRequest.
[0669] wdktags:siteRef: Generates an absolute URL from a relative
URL based on the current site information.
[0670] wdktags:execute: XML fragments produced by Java objects
(Commands) can be embedded in the resulting model document using
the execute tag.
[0671] wdktags:i18n.load: Declares the i18n resource bundle to use
for the labels in the page.
[0672] wdktags:i18n.path: Generates internationalized image path
information using site parameters and information from the resource
bundle specified by wdktags:i18n.load.
[0673] wdktags:i18n.label: Retrieves internationalized labels from
the resource bundle specified by wdktags:i18n.load.
[0674] wdktags:attachTo and wdktags:nodeRef: As described above
these tags can be used to assign widgets to model elements and to
add data dependent information to widgets.
[0675] wdktags:repeat: Provides the capability to replicate widget
components based on elements in the generated model. Used mainly by
list widgets to generate the set of options dynamically.
The Widget Library
[0676] The Web Content Server 800 widget library contains rules
(XSLT templates) for transforming a number of widgets to their HTML
representation. The widget library provides a level of abstraction
between the user interaction component (e.g., a text input field)
and its presentation (e.g., an HTML input field or a WML input
field). This way the content producing model pages can be reused by
different control files--one may deliver the content to a desktop
browser using the HTML widget library, while another may deliver
the same content to a handheld device using a modified version of
the widget library (e.g., using WML).
[0677] The widget library contains widgets for most commonly used
inputs and controls, such as: [0678] Buttons and links: The link
widget can be used to display an image button or regular hyperlink;
[0679] List widgets: the list widget can be used to display common
drop-down menus, set of radio boxes or set of check boxes; [0680]
Input widgets for entering and displaying text values and
passwords; [0681] Hidden variables: for storing values in the
webpage without displaying them; [0682] Etc.
An Example
wdk:input
[0683] The wdk:input widget represents the abstract notion of a
text field. If the model page developer needs a text field to get
information from the user, he or she needs to use the wdk:input
widget. Here is an example of using the input widget:
TABLE-US-00069 <wdk:input name= "inputZip">
<id>inputZip</id> <size>5</size>
<maxlength>5</maxlength>
<value>60202</value> <label>Enter the zip
code</label> <required>false</required>
<password>false</password> </wdk:input>
[0684] The widget transformation transforms this document fragment
to the following:
TABLE-US-00070 <wdk:widget name= "inputZip"> <span align=
"left" class= "Input_Label">Enter the zip code</span>
<span align= "left" class= "Input_Field"> <input
type= "text" name= "inputZip" size= "5" maxlength= "5" value=
"60202"/> </span> </wdk:widget>
[0685] Note that the transformed version of the widget is "wrapped
into" wdk:widget tags. This makes it very simple for the view
transformation to reference the entire widget (e.g. by using
<xsl: apply-templates
select="wdk:widget[@name=`inputZip`]/>). Also note that the
label and the field parts of the widget are wrapped in <span>
tags with the class attribute set to Input_Label and Input_Field,
respectively. These class attributes can be used to customize the
look and feel of the input widget by using Cascading Stylesheets
(CSS) or by writing specific XSLT templates in the view
transformation. For example, the following view transformation
template will set all input labels in the page to use Arial
font:
TABLE-US-00071 <xsl:template match= "span[@class=
`Input_Label`]"> <span style= "font-family:Arial">
<xsl:apply-templates select= "*"/> </span>
</xsl:template>
[0686] The wdk:input widget is implemented as XSLT templates as
shown below:
TABLE-US-00072 1 <xsl:template match="wdk:input">
<xsl:variable name="formElement"> <xsl:choose>
<xsl:when test="boolean(id)"> <xsl:value-of
select="normalize-space(id)"/> </xsl:when>
<xsl:otherwise> <xsl:value-of select="@name"/>
</xsl:otherwise> </xsl:choose> </xsl:variable> 2
<wdk:widget name="{@name}"> 3 <span align="left"
class="Input_Label"> 4 <xsl:if test="required=`TRUE`">
<xsl:attribute name="style">color: red</xsl:attribute>
</xsl:if> <xsl:value-of select="label"/> </span>
5 <span align="left" class="Input_Field">
<xsl:choose> <xsl:when
test="normalize-space(password)=`true`"> <input
name="{$formElement}" type="password"> <xsl:call-template
name="input_attributes"/> </input> </xsl:when>
<xsl:otherwise> <input name="{$formElement}"
type="text"> <xsl:call-template name="input_attributes"/>
</input> </xsl:otherwise> </xsl:choose>
</span> 6 </wdk:widget> </xsl:template> 7
<xsl:template name="input_attributes"> <xsl:if
test="boolean(size)"> <xsl:attribute
name="size"><xsl:value-of select="normalize-space
(size)"/></xsl:attribute> </xsl:if> <xsl:if
test="boolean(maxlength)"> <xsl:attribute
name="maxlength"><xsl:value-of
select="normalize-space(maxlength)"/></xsl:attribute>
</xsl:if> <xsl:if test="boolean(value)">
<xsl:attribute name="value"><xsl:value-of
select="normalize-space(value)"/></xsl:attribute>
</xsl:if> </xsl:template>
[0687] Section 1 contains the match condition for the template:
every wdk:input element in the document will be transformed using
this template. In section 1 the name of the input field is computed
as well. Section 2 shows that this widget (just like all the other
widgets) is nested inside a wdk:widget element, which makes it
simpler to place widgets in the view transform. Section 3 shows how
the different components (the label and the actual text field) are
embedded in an HTML span element. In section 4 the color of the
text label is determined based on the "required" sub-element of the
wdk:input widget. The logic in section 5 determines what type of
text field to generate: either "password" or regular "text" field.
Section 7 shows the template called from section 5 to fill in the
attributes of the generated HTML input element.
List of Widgets Defined in the wdk Widget Library
[0688] wdk:hidden_element: Represents an HTML hidden element. The
widget generates the required element and Javascript functions that
can be invoked to set the value of this element.
[0689] wdk:form: Generates the HTML form element and Javascript
functions needed to manage the form.
[0690] wdk:input: Represents a single line text element. Can render
the widget as a PASSWORD or TEXT HTML form field.
[0691] wdk:list: Represents a widget for selecting an item from a
set of predefined items. Supports four different HTML renderings:
[0692] Dropdown list [0693] List box [0694] Checkbox set [0695]
Radiobutton set
[0696] wdk:link: Represents a link or button. Besides submitting
the form, the link widget can be used to: [0697] Pass parameters
with the invoked URL using <field> subelements; [0698]
Execute an unlimited number of javascript functions before (or
instead of) submission; [0699] Open popup-windows and initialize
the popup-window variables. [0700] Process the data returned by the
popup window invoked by the link
Commands
[0701] Model pages are responsible for producing an XML
representation of the content of the page. This content typically
comes from executing complex business logic (e.g., running database
queries, exercising business APIs, etc.). Although model pages
(being XSP pages) are capable of including programming logic,
including a large amount of code in an XSP page makes it hard to
maintain. To solve this problem Web Content Server 800 introduces
an implementation of the Command pattern (Gamma et al.). A
developer can invoke a command from a model page by using the
execute Web Content Server 800 tag library tag. For example, the
following line <wdktags:execute manager="CatalogCommandMgr"
command="search"/> invokes the execute method of the ICommand
object registered under the "search" key of the CatalogCommandMgr
and replaces the element with the XML result of executing the
method. Here is the implementation of the wdktags:execute tag:
TABLE-US-00073 <?xml version="1.0"?> <xsl:stylesheet
version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/ Transform"
xmlns:xsp="http://www.apache.org/1999/XSP/Core"
xmlns:wdktags="http://www.saba.com/XML/WDK/taglib">
<xsl:template name="command_header"> <xsp:structure>
<xsp:include>com.saba.xml.*</xsp:include>
<xsp:include>com.saba.web.dk.*</xsp:include>
</xsp:structure> <xsp:logic> ICommand cmd = null;
private ICommand getCommand(String mngrName, String cmdName) throws
Exception { Class mngrClass = Class.forName(mngrName);
ICommandManager mngr = (ICommandManager)mngrClass.newInstance( );
return cmd = mngr.getCommand(cmdName); } Node executeCommand(String
mngrName, String cmdName, HttpServletRequest request,
HttpServletResponse response, Document document, Object argument)
throws Exception { StringWriter writer = new StringWriter( );
IXMLVisitor visitor = XML.getDefaultXMLVisitor(writer); cmd =
getCommand(mngrName, cmdName); if (argument != null)
cmd.execute(request, visitor, argument); else cmd.execute(request,
visitor); String xml = writer.toString( ); if (xml.length( ) != 0)
{ InputSource source = new InputSource(new
StringReader(writer.toString( ))); XercesParser parser = new
XercesParser( ); Document doc = parser.parse(source, false); return
document.importNode(doc.getFirstChild( ), true); } else { return
null; } } </xsp:logic> </xsl:template> <xsl:template
match="wdktags:execute"> <xsl:variable
name="returnVariable"> <xsl:choose> <xsl:when
test="boolean(@return)"><xsl:value-of select=
"@return"/></xsl:when>
<xsl:otherwise>wdkExecuteReturn<xsl:value-of select=
"generate-id( )"/></xsl:otherwise> </xsl:choose>
</xsl:variable> </xsp:logic> Node <xsl:value-of
select="$returnVariable"/>; </xsp:logic> <xsp:logic>
{ String wdkMngrName = "<xsl:value-of select="@manager"/>";
String wdkCmdName = "<xsl:value-of select="@command"/>";
Object wdkArgument = null; <xsl:if
test:="boolean(@argument)"> wdkArgument = (Object)
<xsl:value-of select="@argument"/>; </xsl:if>
<xsl:value-of select="$returnVariable"/> =
(Node)executeCommand(wdkMngrName, wdkCmdName, request, response,
document, wdkArgument); } </xsp:logic>
<xsp:expr><xsl:value-of
select="$returnVariable"/></xsp:expr>
</xsl:template> </xsl:stylesheet>
[0702] The stylesheet for the wdktags:execute contains two
templates. The first template (named command_header) is a template
called by the main taglibrary stylesheet to create class level
methods. These methods (getCommand and executeCommand) are called
by the code that results from the transformation of the
wdktags:execute tags. The getCommand method takes two arguments:
the fully qualified name of a Command manager (see below) and a
command name. It returns an ICommand object (see below for details)
that is registered with the command manager by the command name.
The executeCommand method performs the following steps: [0703] 1.
Creates an IXMLVisitor. It uses the default visitor provided by the
XML class. [0704] 2. Uses the getCommand method to get the command
object [0705] 3. Invokes the execute method on the command object.
The created IXMLVisitor is passed to this method along with the
request and argument objects that are passed to the executeCommand
method. [0706] 4. The serialized XML document produced by the
visitor object is parsed and the resulting DOM Node is
returned.
[0707] The template for the execute tag performs the following
steps: [0708] 1. Sets up a DOM Node variable for the node generated
by the executeCommand method. [0709] 2. Invokes the executeCommand
method with the classname of the command manager, the name of the
command and the optional argument, and assigns the returned Node to
the Node variable set up in step 1. [0710] 3. Adds the generated
Node to the document using <xsp:expr> tags.
ICommandManager
[0711] ICommandManager is the interface implemented by individual
command managers. It declares the following method:
[0712] public ICommand getCommand(String name) throws
Exception;
[0713] For convenience an abstract class implementing the ICommand
is defined. This class provides the following API for its
subclasses:
[0714] public void registerCommand (String name, ICommand
command);
[0715] Command managers can extend this class and implement a
single method:
[0716] public abstract void initializeMapStructure( ) throws
Exception;
[0717] For example, the Domain command manager that manages
commands related to security domains has the following
implementation:
TABLE-US-00074 public class DomainCommandManager extends
AbstractCommandManager { public DomainCommandManager ( ) throws
SabaException { super( ); } public void initializeMapStructure( )
throws SabaException { registerCommand("searchForDomain", new
SearchCommand( )); registerCommand("getDomainAndParents", new
ParentsCommand( )); registerCommand("editDomain", new EditCommand(
)); } }
ICommand
[0718] Command objects implement the ICommand interface. The
ICommand interface follows the Command pattern (see Gamma et al.,
1995) and the Prototype pattern. To support prototyping, ICommand
extends the java Cloneable interface. ICommand declares the
following methods:
TABLE-US-00075 public void execute (HttpServletRequest req,
IXMLVisitor visitor) throws Exception; public void execute
(HttpServletRequest req, IXMLVisitor visitor, Object arg) throws
Exception
[0719] These methods are invoked by the wdktags:execute tag in a
model page.
XML Serialization Framework
[0720] Commands are used to generate an XML representation of some
business objects. To make this task simpler, Web Content Server 800
introduces the notion of IXMLVisitor and IXMLObject following the
Visitor pattern (see Gamma et al, 1995.).
IXMLVisitor
[0721] IXMLVisitor declares the following methods:
TABLE-US-00076 public void visit (String prefix, String tagName,
String value) throws XMLVisitorException; public void visit (String
prefix, String tagName, Number value) throws XMLVisitorException;
public void visit (String prefix, String tagName, Locale value)
throws XMLVisitorException; public void visit (String prefix,
String tagName, TimeZone value) throws XMLVisitorException; public
void visit (String prefix, String tagName, Date value) throws
XMLVisitorException; public void visit (String prefix, String
tagName, URL value) throws XMLVisitorException; public void visit
(String prefix, String tagName, IXMLObject value) throws
XMLVisitorException; public void writeOpenTag (String prefix,
String tagname) throws XMLVisitorException; public void
writeCloseTag (String prefix, String tagname) throws
XMLVisitorException; public void createModel (String className)
throws XMLVisitorException;
[0722] Visit methods are declared for most frequently used data
types and for IXMLObject. Besides the visit methods writeOpenTag
and writeCloseTag are also declared. These two methods must be used
when generating nested XML elements. For example, take the
following XML document fragment:
TABLE-US-00077 <doc> <name>A name</name>
<updated> <person>Jill August</person>
<date>1/1/2000</date> </updated> </doc>
[0723] A visitor can produce this document fragment with the
following sequence of visit calls:
TABLE-US-00078 visitor.writeOpenTag(null, "doc");
visitor.visit(null, "name", "A name"); visitor.writeOpenTag(null,
"updated"); visitor.visit(null, "person", "Jill August");
visitor.visit(null, "date", aDate); visitor.writeCloseTag(null,
"update"); visitor.writeCloseTag(null, "doc"):
[0724] Note: the prefix parameter for the visit, writeOpenTag and
writeCloseTag methods is used if the tags to generate are in some
specific namespace. (There is a separate namespace registration
mechanism that associates the prefix with a particular namespace
URLI).
IXMLObject
[0725] The IXMLObject interface declares the following methods:
TABLE-US-00079 public void acceptXMLVisitor (IXMLVisitor visitor)
throws XMLVisitorException; public String getTagName( ); Business
objects that implement the IXMLObject interface can be converted to
XML by a command with a single method call: public void execute
(HttpServletRequest req, IXMLVisitor visitor) throws Exception{
IXMLObject obj = getBusinessObject(req); visitor.visit(null,
"theObject", obj); }
[0726] In the above example the getBusinessObject(req) method call
stands for some business logic that's used to create the business
object (e.g., by using some of the business APIs).
Interconnect Server
[0727] The present invention provides a solution to the needs
described above through a system and method for integrating the
disparate applications, and managing the applications processes in
a hardware resource and user effort efficient manner. The automated
system of the present invention uses a business systems platform
comprised of several unique servers to efficiently manage multiple
applications which are themselves generally distributed across a
network, and to control the execution of the required tasks with
minimum use of redundant data input to the several applications,
thereby minimizing the use of hardware resources and user input
effort.
[0728] As indicated above, in a preferred embodiment, the Platform
Interconnect Server allows a platform installation to interconnect
with external systems. In the preferred embodiment, the
Interconnect Server is a platform for information exchange based on
XML and supports many types of information exchange across
heterogeneous systems. Such heterogeneous systems could include
Enterprise Resource Planning (ERP) systems, e-mail servers, and
other Saba installations. The Interconnect Server allows
interconnection between such external systems and the Interface
Server, Business Server, and Information Server.
[0729] For example, this connection can be for purposes of
importing data from ERP systems, exporting billing information to
accounting systems, making catalog information available for
automated search, or allowing automated purchasing of products. The
Interconnect enables collaboration with the Platform network in a
bi-directional fashion to allow a Platform-enabled site to share
catalog information with the platform network, allow the platform
network to place and track orders, and to share and update learner
profiles. In addition, the process can be reversed: the
platform-enabled site can enhance their internal offering of
courses by including selected platform network courses in their
internal catalog offering.
[0730] In the preferred embodiment, the Interconnect model consists
of three parts: (1) the interconnect backbone and the individual
interconnect components installed on the interconnect backbone (2)
the development API's (both the high-level and the low level
interfaces) and (3) the standard protocols used to communicate
between heterogeneous systems.
[0731] Referring to FIG. 9, the Interconnect Backbone of the
preferred embodiment is shown. The Interconnect Backbone is the
framework that supports all Interconnect components. The
Interconnect Backbone provides the foundation services required by
higher-level services. These foundation services are always
present, and include services for reliable messaging, service
registration, monitoring and management. The Interconnect Backbone
comprises the following components that provide the core
Interconnect services: DeliveryService 905, ServiceManager 910,
Locator 915, and Authenticator 920. The core Interconnect services
are always present.
[0732] The Interconnect Backbone provides a framework for
registering and resolving services. Services are registered and
resolved by name in an interconnect node. The ServiceManager 910 is
a core service for the management of services for the Interconnect
at a particular location. The ServiceManager 910 tracks installed
components, versions and system status. The ServiceManager 910
provides system management capabilities and can be queried for
system status: which other components are present and whether they
are currently running. Components, which implement Interconnection
Services 925, are installed on the Interconnect Backbone at a
specific installation by being registered with the ServiceManager
910. The Locator 915 service is a service component that provides a
way to register and resolve services by name. The Locator 915
services provides a flat registry of services at a particular
interconnect location.
[0733] The DeliveryService 905 is a service component that insures
the reliable delivery of messages. The DeliveryService 905
understands the sender, the recipient and quality of service, but
not the content. DeliveryService 905 works over a variety of
transport protocols by using different DeliveryTransports.
DeliveryTransports are abstract service components that are used by
the DeliveryService 905 to reliably deliver messages over a
particular set of network protocols. Such protocols include
sockets, database logging tables, and HTTP. The messaging model
provided by the DeliveryService 905 provides a mechanism for the
delivery of persistent asynchronous messages using a mailbox
metaphor. Interconnect Services 925 using the DeliveryService 905
register themselves and are assigned an Inbox by the
DeliveryService 905. Subsequently, the registered service may check
for messages at that Inbox. The DeliveryService 905 component is
described in further detail below.
[0734] The Authenticator service insures that messages coming into
the system have the appropriate credentials. Capabilities can be
associated with a particular service and users can be assigned
CapabilitySets. When a service is resolved, the Locator 915 calls
the Authenticator 920 to validate that the requesting user has the
appropriate capabilities to use the service they are requesting. A
Capability is created for each named service in an interconnect
location, for example "SAP/Financials/Accessor". Capabilities have
names and in this case the name of the capability will be the same
name as the service. Once created, Capabilities can then be given
to users who want to access the service. When a message is
constructed, the user adds their capabilities to the message. When
the message is received by the target location the local
DeliveryService 905 validates the capabilities with the
Authenticator 920. The Authenticator service is the generator of
capabilities and capability keys. If a passed in capability doesn't
have the appropriate key the capability is not set and the
authentication is rejected. The service is also used by other core
Interconnect Services for authenticating particular application
level requests. Since a capability is a name-key mapping, an
interconnect service can create capabilities for any purpose
desired.
[0735] Other interconnect services are implemented like the core
Interconnect Services described above. These Interconnect Services
register and resolve by name and respond to and send Interconnect
messages. Services are configured and managed using java classes
and scripts. When interconnect components are installed on the
Interconnect Backbone, a site is said to be "connector enabled".
These components allow connections to external systems such as ERP
systems to import, export, and synchronize data.
[0736] Key to the Interconnect design is the separation of
interface from implementation. Many of the service components are
broken into a generic platform independent portion and a platform
specific portion that minimizes the impact of changes to the
implementation in the future. Most connector components consist of
a public service component (which is generic) and a service
sub-component (which is system specific). The implementation of a
connector in this framework consists of providing concrete
implementations for the service sub-components and creating XSL
stylesheets that describe mappings between a Local Format (LF) and
Interchange Format (IF). Local formats are system-specific
representations of the data supported by a service, while
Interchange Formats are universal representations used for exchange
between systems.
[0737] Referring to FIG. 9, these Connectors services may include
Monitor 945, Accessor 935, Importer 940, and Updater (not shown).
Accessors, Importers, and Updaters are essentially thin wrappers
around XSL stylesheet operations. They translate documents between
native formats and the Interchange format using a predefined
stylesheet. These connector services may also contain additional
logic for cases where a single Interchange format document
represents multiple native documents, and vice versa. A more
detailed description of the service components for these Connector
services and their implementation on the Interconnect Backbone
follows.
[0738] The Accessor 935 is a public service component that is used
to extract objects from the source representation and convert them
to a Interchange Format (IF). An Accessor 935 is configured to use
a particular AccessorReader 950 to extract the objects from the
source system and collaborate with Translators to perform the
conversion to IF. The AccessorReader 950 is an abstract service
sub-component that is used by an Accessor 935 to extract an object,
or set of objects from a source system and convert them into an
Interchange Format. Concrete implementations of the AccessorReader
950 are system specific and use the native API of the source
system.
[0739] The Importer 940 is a public service component that is used
to import objects from Interchange Format to the target
representation. An Importer 940 will collaborate with Translators
to perform the conversion from IF and be configured to use a
particular ImporterWriter 960 to inject the objects into the target
system. The ImporterWriter 960 is an abstract service sub-component
that is used by an Importer 940 to convert an object, or set of
objects into a Local Format (LF) and write them to a source system.
Concrete implementations of the ImporterWriter 960 are system
specific and use the native API of the target system.
[0740] The Monitor 945 is a public service component that monitors
changes to local objects and reports changes to interested parties
in Interchange Format. Clients can register to receive notification
of the change only, or have the changed object sent with the
notification. A Monitor 945 is configured to use a particular
ChangeManager 955 to map changes in the source system to a standard
event format that the monitor can use. The ChangeManager 955 is an
abstract service sub-component that is used by a Monitor 945 to map
local events into the standard event format. Concrete
implementations of the ChangeManager 955 are system specific and
use the native API of the source system to capture events.
[0741] When the Monitor 945 receives an event from the
ChangeManager 955, it checks to see if the object needs to be sent
with the notification. If so, the Monitor 945 will collaborate with
the Accessor 935 and Mapper to provide the conversion from source
object to Interchange Format. The Monitor 945 uses the Mapper to
find the platform ID associated with the local identifier in the
event. This platform ID is then used to request the object from the
Accessor 935. The Mapper is a utility that provides object and
class level mapping services between representations, each
connector framework contains a single instance of the Mapper. The
Mapper data is persistent this enables the cross reference data to
survive restarts. The Mapper maintains maps for (1) Platform ID to
Document Type, (2) Local ID to Platform ID, and (3) Platform
(Interconnect) user to Local (mapped system) user. The Mapper
(discussed in detail in a later section) converts a local object Id
(a combination of Id and Class type) into a Platform Object Id
(POID), POID is an Id that is unique across applications. POID is a
serializable class that has URL representation
[0742] "http://"+host+"/interconnect/"+platform+"/"+seqNo
[0743] where host->is the hostname of the machine on which the
connector is running [0744] platform->a parameter defined at the
Saba site level. This parameter will make the POID unique if
multiple Saba sites are running on the same machine. [0745]
SeqNo->is a sequence number that that is unique for a host.
[0746] Example of a POID is
[0747] http://jade/interconnect/Saba/1 this could be a
representation of local id emplo000000000001000 with class type
com.saba.busobj.SabaEmployee. This representation can be converted
to instance of POID by using static method in the POID class.
[0748] POID class definition is
TABLE-US-00080 public class POID implements IXMLRenderable {
private GenericObjectID mLocalID; private URL mURL; private long
mId; public POID (GenericObjectID localID) { mId = getNextId( );
try { mLocalID = localID; mURL = new URL(getURLPrefix( ) +
localID.toString( ) + "/" + mId); } catch (MalformedURLException x)
{ } } public void setLocalID(GenericObjectID localID) { try {
mLocalID = localID; mURL = new URL(getURLPrefix( ) +
localID.toString( ) + "/" + mId); } catch (MalformedURLException x)
{ } if (mId == -1) { mId = getNextId( ); } } public String
toString( ) { return mURL.toString( ); } public URL getURL( ) {
return mURL; } public GenericObjectID getLocalID( ) { return
mLocalID; } public static POID getPOID(String url) { String
temp=new String(url); int pos=temp.lastIndexOf("/"); String
temp1=temp.substring(pos+1); Long temp2=Long.valueOf(temp1); long
hash=temp2.longValue( ); POID poid=new POID( ); poid.mId=hash; try
{ poid.mURL=new URL(url); } catch(MalformedURLException x) { }
return poid; }
[0749] Mapper stores the cross reference between the local Id and
the POID representation of the local Id. The Mapper also stores
cross reference between foreign POID and local Id in the case where
the Object originated from a foreign system.
[0750] A Transformer is a utility that provides translation
services between representations using mapping data and XSL style
sheets. A Transformer wraps a particular XML parser and XSL
translator. The Accessor calls an implementation of the transformer
and passes the Local Format and the stylesheet, the transformer
translates the Local Format into Interchange Format.
[0751] Implementing a connector involves building four platform
specific components and defining a set of document, object and user
mappings. The platform specific components are described in detail
below and include the (1) ChangeManager 955 (maps system events to
Monitor 945 events), (2) AccessorReader 950 (extracts objects from
the system in XML format), (3) ImporterWriter 960 (injects objects
into the system from XML format), and (4) LocalObjectID
(Encapsulates the system object identifier, this is not required if
the system can use the GenericObjectID available). Additionally,
the types of documents to be exchanged need to be defined. Once
these are determined and their format defined, XSL style sheets
need to be written which convert Interchange Format to the system
specific XML format and vice versa.
[0752] At system deployment time, a number of mappings need to be
defined. These include (1) Document type to style sheet, (2) local
User to system user, and (3) the Translator the connector will
use.
[0753] The ChangeManager 955 sub-component monitors the native
system for all events such as Insert/Update/Delete on objects. It
can interact with the event notification mechanism of the native
system to capture all the events and then pass these events to the
monitor for further handling. The ChangeManager 955 accepts events
from the native system, converts these events into MonitorEvent
Objects, and forwards these to the Monitor 945 using the method
IChangeManagerAdaptor.notify( ) method. Once the Change Manager
passes an event on to the Monitor 945, it is then the
responsibility of the Monitor 945 to reliably deliver the request
on to any subscribers who have registered interest. The Monitor 945
will filter out any events that are not subscribed to.
Specifically, the Change Manager is responsible for (1) keeping
track of all the events that take place in the native system, (2)
creating MonitorEvent Objects for all events supported by the
native change management, (3) Calling the notify method of the
Monitor with a given event.
[0754] ChangeManager 955 requires a reference to its owning Monitor
945 class to invoke its notify( ) event. It also needs a LocalUser
object to obtain credential information. These references are
provided during construction.
TABLE-US-00081 public abstract class ChangeManager throws
connectorException { public ChangeManager(Monitor theMonitor,
UserObject user) public void shutdown( ) }
[0755] As mentioned above, the ChangeManager 955 converts each
system event into a MonitorEvent object, which it passes on to the
monitor by calling its notify method. The Monitor Event class is as
follows:
TABLE-US-00082 public class MonitorEvent { public Object objectID;
public String eventType; public String docType; public Boolean
applyStyleSheet; }
[0756] The Monitor is responsible for implementing the interface
IChangeManagerAdaptor which currently defines a single method.
TABLE-US-00083 public interface IChangeManagerAdapter { public void
notify(MonitorEvent event); }
[0757] The ChangeManager.shutdown( ) method is invoked by the
Monitor 945 and is used to gracefully disconnect the ChangeManager
955. When shutdown( ) is called, the ChangeManager 955 is
responsible for closing any open connections, unregistering itself
from the native event system and taking any other action required
to perform a clean shutdown. The ChangeManager 955 can shut down
itself if required by using this method.
[0758] The AccessorReader 950 is a platform specific sub-component
of the Accessor 935. It is responsible for extracting an object
from the native system in a convenient XML representation. The
representation produced must be complete enough to allow it to be
transformed into the appropriate document in Interchange Format. An
instance of an AccessorReader 950 will service the requests of a
particular user. When an AccessorReader 950 is created a UserObject
that identifies the system user is passed to it in its constructor.
The AccessorReader 950 is responsible for making managing a
connection to the native system on behalf of this user. The
Accessor 935 is responsible for making sure that incoming requests
are assigned to the appropriate AccessorReader 950 for the
requesting user. The AccessorReader calls the Mapper to get the
Platform Id (POID) for the local Id representation, the local Id
representation is replaced with the POID.
[0759] An implementation of an AccessorReader 950 will be derived
from the abstract class of the same name:
TABLE-US-00084 public abstract class AccessorReader implements
IAccessorReader { public AccessorReader(UserObject user); } public
interface IAccessorReader { public Reader
extractObjectReader(Object localID) throws IOException,
ConnectorException; public URL extractObjectURL(Object localID)
throws MalformedURLException, ConnectorException; public void
shutdown( ); }
[0760] Specifically, the AccessorReader 950 is responsible for (1)
Establishing a connection into the system based on the User Id and
Credentials (2) Extracting the required object based on the
information passed in Local Object (3) Transforming that Object
into a serialized representation, which is an XML document (4) If
the object type of the local object maps to more than one object in
native system, then extracting all the corresponding objects in the
current context, (5) As the objects to be transported to and from
the native system are known, information about which objects have
to be extracted for a given object can be maintained specifically
for the current implementation, (6) Serializing this localObject/s
into a single Local XML representation (7) Returning this XML
document back to the Accessor 935, (8) Providing a clean shutdown
by closing the connection. The shutdown method is invoked by the
Accessor 935 when it needs to shutdown the AccessorReader 950.
[0761] The ImporterWriter 960 is a platform specific sub-component
of the Importer 940. It is responsible importing an object into the
native system from a convenient XML representation. The
representation must be able to be produced from a document in
Interchange Format using XSL style sheet transformations. Like the
AccessorReader 950, an instance of an ImporterWriter 960 will
service the requests of a particular user. Once an Object has been
imported the newly created local Id and the Foreign POID sent along
with the Interchange format are inserted into the Mapper for
subsequent use. Mapper is discussed in detail in a later
section.
[0762] An implementation of an ImporterWriter 960 will be derived
from the abstract class of the same name:
TABLE-US-00085 public abstract class ImporterWriter implements
IImporterWriter { Object mUser; public ImporterWriter(UserObject
user) { mUser = user; } public interface IImporterWriter { /**
Insert the objects from the input stream and return an array of
native (local) identifiers for the new objects. The input stream is
in a localized XML format. */ public Object
insertObjectFromStream(Writer in) throws ConnectorException; /**
Insert the objects from the URL and return an array of native
(local) identifiers for the new objects. The input URL is in a
localized XML format. */ public Object insertObjectFromURL(URL url)
throws MalformedURLException, ConnectorException; public void
shutdown( ); }
[0763] The ImporterWriter 960 is responsible for (1) Establishing a
connection into the system based on the User Id and Credentials (2)
Mapping the single XML document received to one or more objects
required to be inserted into the native system (3) Converting the
Native XML representation of the object into native system specific
format (4) Based on the event to be performed, insert, update or
delete the database (5) In case of a new object being inserted,
returning the local identifier for the object inserted (6)
Providing a clean shutdown by closing the connection. The Importer
940 invokes the shutdown method when it needs to shutdown the
ImporterWriter 960.
[0764] The UserObject encapsulates system specific User information
for an application level login (user id and password). The platform
specific parts of the connector services will use this information
to log into the target system. For example a ChangeManager 955 may
need to login to the database to trap the events. The UserObject
object encapsulates a string-based userID and the notion of
Credentials. Each Platform implementation provides its own
LocalUser object. Implementations provide a subclass of the
credentials Object customized for the security requirements of
their system; in the simplest case the credentials are a String
password.
TABLE-US-00086 public class UserObject implements Serializable {
String mUsername; Object mCredentials; public UserObject(String
username, Object credentials) { mUsername = username; mCredentials
= credentials; } public String getUsername( ) { return mUsername; }
public Object getCredentials( ) { return mCredentials; } }
[0765] The Local object contains information about the object that
the connector uses uniquely identify an object in the native
system. It holds the following information about the object (1) ID:
An opaque object identifier, and (2) aClass: the type or class of
the object.
[0766] The LocalObjectID class is defined as:
TABLE-US-00087 public class LocalObjectID { Object mID; Object
mClass; public LocalObjectID(Object ID, Object aClass) { mID = ID;
mClass = aClass; } public Object getID( ) { return mID; } public
Object getObjectClass( ) { return mClass; } }
[0767] Referring to FIG. 10, an example of the operation of the
above Interconnect services in which a purchase order is delivered
from a Source site 1000 to a target SAP system 1005 utilizing the
Interconnect Server 1010 is set forth. An Importer component 1015
resides on the target SAP system and the Requestor 1020, Monitor
1025, Event Manager 1030, Accessor 1035, and Transformer 1040
components reside on the Interconnect Server 1010. At step 1, At
the Source site 1000, a Purchase order 1045 is generated and a
"SabaInvoice" object is created. At step 2, the Purchase Order 1045
is saved. Because it needs to be synchronized with a remote system,
this triggers a pre-registered ChangeManager event at the
EventManager 1030. At step 3, the ChangeManager passes the unique
id of the SabaInvoice to the Monitor 1025. At step 4, the Monitor
1025 instructs the Accessor 1035 to retrieve the SabaOrder in
Interchange Format. At step 5, the Accessor 1035 retrieves the
SabaInvoice in serialized, canonical XML format. This is an
internal XML format that varies for each business object. Its
essential feature is that it contains all relevant information
about the PO in attribute/value format. Step 5 uses a standard
method available for all SabaObjects.
[0768] The following example Local Format document is a sample
SabaInvoice serialized into XML:
TABLE-US-00088 <?xml version="1.0" standalone="yes"?>
<SabaObjectSerialization xmlns:dt="urn:w3-org:xmldatatypes">
<SabaObject type="com.saba.busobj.SabaInvoice"
id="invce000000000001000" status="new"> <amt_paid
dt:type="number">0.0</amt_paid> <other_charges
dt:type="number">0.0</other_charges> <acct_id
idref="http://spanuganti/interconnect/Saba/com.saba.interconnect.ObjectID@-
94902deb/206"/> <updated_by
dt:type="string">uone</updated_by> <balance
dt:type="number">425.0</balance> <updated_on
dt:type="dateTime">2000-11-10 19:17:40.000</updated_on>
<created_by dt:type="string">uone</created_by>
<created_id
idref="http://spanuganti/interconnect/Saba/com.saba.interconnect.ObjectID@-
170064/6"/> <inv_date dt:type="dateTime">2000-11-10
19:17:40.000</inv_date> <created_on
dt:type="dateTime">2000-11-10 19:17:40.000</created_on>
<split dt:type="string">domin000000000000001</split>
<status dt:type="number">100</status> <time_stamp
dt:type="string">200011101917399262</time_stamp> <flags
dt:type="string">0000000000</flags> <invoice_no
dt:type="string">001000</invoice_no> <currency_id
idref="http://spanuganti/interconnect/Saba/com.saba.interconnect.ObjectID@-
14966/34"/> <total_charges
dt:type="number">425.0</total_charges> </SabaObject>
<SabaObject type="com.saba.busobj.SabaInvoiceItem"
id="invit000000000001000" status="new"> <order_item_id
idref="ordit000000000001060"/> <invoice_id
idref="http://bnemazie/interconnect/Saba/com.saba.interconnect.ObjectID@c8-
2f961c/101"/> <time_stamp
dt:type="string">200011101917406145</time_stamp>
</SabaObject> <SabaObject type="com.saba.busobj.SabaOrder"
id="extor000000000001040" status="new"> <city
dt:type="string">Sunnyvale</city> <addr1
dt:type="string">Addr 11</addr1> <country
dt:type="string">US</country> <shipped_amt
dt:type="number">0.0</shipped_amt> <state
dt:type="string">CA</state> <discount
dt:type="number">0.0</discount> <updated_by
dt:type="string">UONE</updated_by> <order_no
dt:type="string">001040</order_no> <updated_on
dt:type="dateTime">2000-11-10 19:13:19.000</updated_on>
<created_by dt:type="string">uone</created_by>
<created_id
idref="http://spanuganti/interconnect/Saba/com.saba.interconnect.ObjectID@-
170064/6"/> <shipped_attn dt:type="string">test1
test1</shipped_attn> <contact_id
idref="http://bnemazie/interconnect/Saba/com.saba.interconnect.ObjectID@c9-
162811/1"/> <created_on dt:type="dateTime">2000-11-10
19:13:19.000</created_on> <sold_by_id
idref="http://spanuganti/interconnect/Saba/com.saba.interconnect.ObjectID@-
170064/6"/> <split
dt:type="string">domin000000000000001</split> <status
dt:type="number">400</status> <time_stamp
dt:type="string">200011101917406145</time_stamp>
<company_id
idref="http://spanuganti/interconnect/Saba/com.saba.interconnect.ObjectID@-
94902deb/206"/> <territory_id
idref="terri000000000000001"/> <conf_type
dt:type="number">0</conf_type> <zip
dt:type="string">94086</zip> <account_id
idref="http://spanuganti/interconnect/Saba/com.saba.interconnect.ObjectID@-
94902deb/206"/> <currency_id
idref="http://spanuganti/interconnect/Saba/com.saba.interconnect.ObjectID@-
14966/34"/> <status_flag
dt:type="string">2000200000</status_flag>
<total_charges dt:type="number">425.0</total_charges>
<children> <SabaObject
type="com.saba.busobj.SabaOrderItem" id="ordit000000000001061"
status="new"> <order_id idref="extor000000000001040"/>
<unit_cost dt:type="number">425.0</unit_cost>
<description dt:type="string">Inventory1</description>
<actual_qty dt:type="number">1</actual_qty> <part_id
idref="prdct000000000001022"/> <pkg_item_id
idref="ordit000000000001061"/> <create_on
dt:type="dateTime">2000-11-10 19:13:28.000</created_on>
<req_qty dt:type="number">1</req_qty> <delivered_on
dt:type="dateTime">2000-11-10 19:17:13.000</delivered_on>
<status dt:type="number">300</status> <time_stamp
dt:type="string">200011101917406145</time_stamp>
<Custom0 dt:type="string">Billed</Custom0> <flags
dt:type="string">0000000000</flags> <total_cost
dt:type="number">425.0</total_cost> <item_typ
dt:type="number">1</item_typ> <billing_state
dt:type="number">101</billing_state> </SabaObject>
<SabaObject type="com.saba.busobj.SabaOrderItem"
id="ordit000000000001060" status="new"> <order_id
idref="extor000000000001040"/> <unit_cost
dt:type="number">0.0</unit_cost> <description
dt:type="string">Default Default</description>
<actual_qty dt:type="number">1</actual_qty> <part_id
idref="shpmd000000000000001"/> <pkg_item_id
idref="ordit000000000001060"/> <created_on
dt:type="dateTime">2000-11-10 19:13:27.000</created_on>
<req_qty dt:type="number">1</req_qty> <delivered_on
dt:type="dateTime">2000-11-10 19:17:13.000</delivered_on>
<status dt:type="number">300</status> <time_stamp
dt:type="string">200011101917406145</time_stamp>
<Custom0 dt:type="string">Billed</Custom0> <flags
dt:type="string">0000000000</flags> <total_cost
dt:type="number">0.0</total_cost> <item_typ
dt:type="number">6</item_typ> <billing_state
dt:type="number">101</billing_state> </SabaObject>
</children> </SabaObject> <SabaObject
type="com.saba.busobj.SabaInvoiceItem" id="invit000000000001001"
status="new"> <order_item_id
idref="ordit000000000001061"/> <invoice_id
idref="http://bnemazie/interconnect/Saba/com.saba.interconnect.ObjectID@c8-
2f961c/101"/> <time_stamp
dt:type="string">200011101917406145</time_stamp>
</SabaObject> </SabaObjectSerialization>
[0769] At step 6, the Accessor 1035 then transforms the XML
document into an Interchange document format. The Accessor 1035
accomplishes this by passing the source document and an XSL
stylesheet to the Transformer 1040.
[0770] The following is a sample purchase order XSL stylesheet:
TABLE-US-00089 <!--COPYRIGHT NOTICE Copyright (c) 1997-2000 Saba
Software Inc., 2400 Bridge Parkway, Redwood Shores, California
94065-1166 USA. All rights reserved.--> <xsl:stylesheet
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"> <xsl:output
omit-xml-declaration="no" indent="yes" method="xml"/>
<xsl:template match="SabaObjectSerialization">
<SYNC_INVOICE_001> <CNTROLAREA> <BSR>
<VERB>SYNC</VERB> <NOUN>INVOICE</NOUN>
<REVISION>001</REVISION> </BSR> <SENDER>
<LOGICALID/> <COMPONENT/> <TASK/>
<REFERENCEID/> <CONFIRMATION/> <LANGUAGE/>
<CODEPAGE/> <AUTHID> <xsl:value-of
select="created_by"/> </AUTHID> </SENDER>
<DATETIME qualifier="CREATION"> <YEAR> <xsl:value-of
select="substring(//created_on,7,4)"/> </YEAR>
<MONTH> <xsl:value-of
select="substring(//created_on,1,2)"/> </MONTH>
<DAY> <xsl:value-of
select="substring(//created_on,4,2)"/> </DAY>
<HOUR/> <MINUTE/> <SECOND/> <SUBSECOND/>
<TIMEZONE/> </DATETIME> </CNTROLAREA>
<DATAAREA> <xsl:for-each select="//
SabaObject[@type=`com.saba.busobj.SabaInvoice`]">
<INVOICE> <INVDATE> <xsl:value-of
select="//inv_date"/> </INVDATE> <CURRENCYID>
<xsl:value-of select="//currency_id/@idref"/>
</CURRENCYID> <INVNO> <xsl:value-of
select="//invoice_no"/> </INVNO> <INVOICEID>
<xsl:value-of select="@id"/> </INVOICEID>
<TOTALCHARGES> <xsl:value-of select="//total_charges"/>
</TOTALCHARGES> <ACCTID> <xsl:value-of
select="acct_id/@idref"/> </ACCTID> <CREATEDID>
<xsl:value-of select="created_id/@idref"/> </CREATEDID>
<UPDATEDON> <xsl:value-of select="updated_on"/>
</UPDATEDON> <ORDERID> <xsl:value-of
select="order_id/@idref"/> </ORDERID> <BALANCE>
<xsl:value-of select="balance"/> </BALANCE>
<AMTPAID> <xsl:value-of select="amt_paid"/>
</AMTPAID> <OTHERCHARGES> <xsl:value-of
select="other_charges"/> </OTHERCHARGES> <STATUS>
<xsl:value-of select="status"/> </STATUS> <FLAGS>
<xsl:value-of select="flags"/> </FLAGS> <SPLIT>
<xsl:value-of select="split"/> </SPLIT> <POID>
<xsl:value-of select="po_id/@idref"/> </POID>
<REMINVDATE/> <REMINVID/> </INVOICE>
</xsl:for-each> <xsl:for-each select="//
SabaObject[@type=`com.saba.busobj.SabaInvoiceItem`]">
<xsl:variable name="ORDERITEMID"> <xsl:value-of
select="order_item_id/@idref"/> </xsl:variable>
<xsl:for-each select="//SabaObject[@type=
`com.saba.busobj.SabaOrderItem`]"> <xsl:if
test="$ORDERITEMID=@id"> <ITEM> <ACCTID>
<xsl:value-of select="//account_id/@idref"/> </ACCTID>
<TOTALCOST> <xsl:value-of select="total_cost"/>
</TOTALCOST> <DESCRIPTN> <xsl:value-of
select="description"/> </DESCRIPTN> <UNITCOST>
<xsl:value-of select="unit_cost"/> </UNITCOST>
<ACTUALQTY> <xsl:value-of select="actual_qty"/>
</ACTUALQTY> <LINEID> <xsl:value-of
select="@id"/> </LINEID> <ATTRIBUTE1>
<xsl:value-of select="@id"/> </ATTRIBUTE1>
<xsl:variable name="STUDENTID"> <xsl:value-of
select="student_id/@idref"/> </xsl:variable>
<xsl:for-each select="//SabaObject[@id=$STUDENTID]">
<xsl:variable name="STUDENTNAME"> <xsl:value-of
select="lname"/>,<xsl:value-of
select="fname"/>,Phone:<xsl:value-of select="workphone"/>
</xsl:variable> <ATTRIBUTE2> <xsl:value-of
select="$STUDENTNAME"/> </ATTRIBUTE2>
</xsl:for-each> </ITEM> </xsl:if>
</xsl:for-each> </xsl:for-each> <xsl:for-each
select="//SabaObject[@type= `com.saba.busobj.SabaInvoice`]">
<USERAREA> <OBJSTATUS> <xsl:value-of
select="@status"/> </OBJSTATUS> <OBJTYPE>
<xsl:value-of select="@type"/> </OBJTYPE>
<AMOUNT_INCLUDES_TAX_FLAG>N</ AMOUNT_INCLUDES_TAX_FLAG>
</USERAREA> </xsl:for-each> </DATAAREA>
</SYNC_INVOICE_001> </xsl:template>
</xsl:stylesheet>
[0771] The following is the equivalent Interchange Format document
generated by the stylesheet transformation, an Invoice in OAG BOD
format.
TABLE-US-00090 <SYNC_INVOICE_001> <CNTROLAREA>
<BSR> <VERB>SYNC</VERB>
<NOUN>INVOICE</NOUN>
<REVISION>001</REVISION> </BSR> <SENDER>
<LOGICALID/> <COMPONENT/> <TASK/>
<REFERENCEID/> <CONFIRMATION/> <LANGUAGE/>
<CODEPAGE/> <AUTHID/> </SENDER> <DATETIME
qualifier="CREATION"> <YEAR>1-10</YEAR>
<MONTH>20</MONTH> <DAY>0-</DAY>
<HOUR/> <MINUTE/> <SECOND/> <SUBSECOND/>
<TIMEZONE/> </DATETIME> </CNTROLAREA>
<DATAAREA> <INVOICE> <INVDATE>2000-11-10
19:17:40.000</INVDATE>
<CURRENCYID>http://spanuganti/interconnect/
Saba/com.saba.interconnect.ObjectID@14966/34</CURRENCYID>
<INVNO>001000</INVNO>
<INVOICEID>invce000000000001000</INVOICEID>
<TOTALCHARGES>425.0</TOTALCHARGES>
<ACCTID>http://spanuganti/interconnect/
Saba/com.saba.interconnect.ObjectID@94902deb/206</ACCTID>
<CREATEDID>http://spanuganti/interconnect/
Saba/com.saba.interconnect.ObjectID@170064/6</CREATEDID>
<UPDATEDON>2000-11-10 19:17:40.000</UPDATEDON>
<ORDERID/> <BALANCE>425.0</BALANCE>
<AMTPAID>0.0</AMTPAID>
<OTHERCHARGES>0.0</OTHERCHARGES>
<STATUS>100</STATUS>
<FLAGS>0000000000</FLAGS>
<SPLIT>domin000000000000001</SPLIT> <POID/>
<REMINVDATE/> <REMINVID/> </INVOICE> <ITEM>
<ACCTID>http://spanuganti/interconnect/
Saba/com.saba.interconnect.Object ID@94902deb/206</ACCTID>
<TOTALCOST>0.0</TOTALCOST> <DESCRIPTN>Default
Default</DESCRIPTN> <UNITCOST>0.0</UNITCOST>
<ACTUALQTY>1</ACTUALQTY>
<LINEID>ordit000000000001060</LINEID>
<ATTRIBUTE1>ordit000000000001060</ATTRIBUTE1>
</ITEM> <ITEM>
<ACCTID>http://spanuganti/interconnect/
Saba/com.saba.interconnect.Object ID@94902deb/206</ACCTID>
<TOTALCOST>425.0</TOTALCOST>
<DESCRIPTN>Inventory1</DESCRIPTN>
<UNITCOST>425.0</UNITCOST>
<ACTUALQTY>1</ACTUALQTY>
<LINEID>ordit000000000001061</LINEID>
<ATTRIBUTE1>ordit000000000001061</ATTRIBUTE1>
</ITEM> <USERAREA>
<OBJSTATUS>new</OBJSTATUS>
<OBJTYPE>com.saba.busobj.SabaInvoice</OBJTYPE>
<AMOUNT_INCLUDES_TAX_FLAG>N</ AMOUNT_INCLUDES_TAX_FLAG>
</USERAREA> </DATAAREA> </SYNC_INVOICE_001>
[0772] At step 7, the Monitor 1025 receives the Interchange Format
document back from the Accessor 1035. At step 8, the Monitor 1025
instructs the Requestor 1020 to deliver the Invoice to the SAP
system. At step 9, the Process Invoice document is actually
delivered over the network to the SAP system. The Requestor 1020
reliably ensuring that the Invoice is actually delivered and
received. At step 10, the Process Invoice document is inserted into
the SAP system as a new Invoice. Step 10 is performed by the SAP
Importer. There are several possibilities for the implementation of
the SAP Importer, depending on the level of functionality provided
by SAP: (1) SAP supports the Interchange Document format directly,
in which case this step is trivial, or (2) SAP supports a
proprietary XML format, in which case a stylesheet can be used to
transform the Invoice into SAP's proprietary format, or (3) SAP
supports a proprietary API, which is used to read and process the
XML document, either in its original format or after a stylesheet
transformation into a more convenient format.
[0773] As another example, an employee record maintained in an
external system is reflected in a SABA site. An administrator
registers a callback event with an Interconnect enabled human
resources (HR) system. A change in the HR system generates an event
that is captured by the external system Monitor. The Monitor
requests the HR data from the Accessor. The external system
Accessor generates the updated HR record as an Interchange
Document. The following is another example Interchange Format
document, a Sync Personnel BOD:
TABLE-US-00091 <SYNC_EMPLOYEE_001> <CNTROLAREA>
<BSR> <VERB>SYNC</VERB>
<NOUN>EMPLOYEE</NOUN>
<REVISION>001</REVISION> </BSR> <SENDER>
<LOGICALID/> <COMPONENT/> <TASK/>
<REFERENCEID/> <CONFIRMATION/> <LANGUAGE/>
<CODEPAGE/> <AUTHID/> </SENDER> <DATETIME
qualifier="CREATION"> <YEAR/> <MONTH/> <DAY/>
<HOUR/> <MINUTE/> <SECOND/> <SUBSECOND/>
<TIMEZONE/> </DATETIME> </CNTROLAREA>
<DATAAREA> <SYNC_EMPLOYEE> <EMPLOYEE> <NAME
index="1">MR.</NAME> <NAME
index="2">testfirst</NAME> <NAME
index="3">testlast</NAME>
<EMPLOYEEID>http://bnemazie/interconnect/Saba/
com.saba.interconnect.ObjectID@170179/6805</EMPLOYEEID>
<EMPLOYEETYPE>Permanent</EMPLOYEETYPE> <SYNCIND/>
<DUNSNUMBER/> <ADDRESS> <ADDRLINE index="1"/>
<ADDRLINE index="2"/> <CITY/> <COUNTRY/>
<POSTALCODE/> <STATEPROVN/> <TELEPHONE1/>
<TELEPHONE2/> <FAX1/> <PARENTID/> <EMAIL/>
</ADDRESS> <NAME2/> <CURRENCY/>
<DESCRIPTN/> </EMPLOYEE> <USERAREA>
<MNAME/> <TERRITORYID/> <COMPANYID/>
<STARTEDON>2000-07-24 00:00:00.0</STARTEDON>
<TERMINATEDON/>
<LOCATIONID>http://bnemazie/interconnect/Saba/
com.saba.interconnect.ObjectID@cd92/6801</LOCATIONID>
<RATE/> <SSNO>111-11-2222</SSNO>
<GENDER>0</GENDER> <SHORTDESCRIPTN/>
<JOBTYPEID/> <MANAGERID/> <QUOTA/>
<UPDATEDON>provide</UPDATEDON>
<UPDATEDBY>provide</UPDATEDBY> <MAXDISCOUNT/>
<HOMEDOMAIN/> <USERNAME>1093-202</USERNAME>
<FLAGS>0</FLAGS> <PASSWORD/> <STATUS>Full
Time</STATUS> <LOCALEID/>
<EMPLOYEENO>185</EMPLOYEENO> <SPLIT/>
<CREATEDON>provide</CREATEDON> <OBJTYPE/>
<OBJSTATUS>new</OBJSTATUS> <DESIREDJOBTYPEID/>
</USERAREA> </SYNC_EMPLOYEE> </DATAAREA>
</SYNC_EMPLOYEE_001>
[0774] The Monitor then receives the BOD from the Accessor and
instructs the external system Requestor to deliver the personnel
change to the SABA system. The Requestor then delivers the Sync
Personnel document over the network to the SABA system. The SABA
Updater receives the Sync Personnel document. It uses an XSL
stylesheet to transform the document into the canonical format used
internally. The following is an example XSL personnel
stylesheet:
TABLE-US-00092 <xsl:stylesheet
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<!--COPYRIGHT NOTICE Copyright (c) 1997-2000 Saba Software Inc.,
2400 Bridge Parkway, Redwood Shores, California 94065-1166 USA. All
rights reserved.--> <xsl:output indent="yes" method="xml"
omit-xml- declaration="no"/> <xsl:template match="*|/">
<xsl:apply-templates/> </xsl:template> <xsl:template
match="text( )|@*"> <xsl:value-of select="."/>
</xsl:template> <xsl:template
match="SYNC_EMPLOYEE_001"> <xsl:for-each select="/">
<SabaObjectSerialization xmlns:dt="urn:w3- org:xmldatatypes">
<SabaObject> <xsl:attribute
name="type">com.saba.busobj.SabaEmployee</xsl:attribute>
<xsl:attribute name="status"> <xsl:value-of
select="//USERAREA/OBJSTATUS"/> <xsl:if
test="//USERAREA/OBJSTATUS=``"/> </xsl:attribute>
<xsl:attribute name="id"> <xsl:value-of
select="//EMPLOYEEID"/> <xsl:if test="//EMPLOYEEID=``"/>
</xsl:attribute> <title dt:type="string" dt:size="10">
<xsl:value-of select="//NAME[1]"/> </title> <fname
dt:type="string" dt:size="25"> <xsl:value-of
select="//NAME[2]"/> <xsl:if test="//NAME[2]=``"/>
</fname> <lname dt:type="string" dt:size="25">
<xsl:value-of select="//NAME[3]"/> <xsl:if
test="//NAME[3]=``"/> </lname> <mname dt:type="string"
dt:size="25"> <xsl:value-of select="//USERAREA/MNAME"/>
</mname> <homephone dt:type="string" dt:size="25">
<xsl:value-of select="//TELEPHONE1"/> </homephone>
<workphone dt:type="string" dt:size="25"> <xsl:value-of
select="//TELEPHONE2"/> </workphone> <fax
dt:type="string" dt:size="25"> <xsl:value-of
select="//FAX1"/> </fax> <created_on dt:type="string"
updateFlag="No"> <xsl:attribute
name="provide">true</xsl:attribute> </created_on>
<created_by dt:type="string" updateFlag="No">
<xsl:attribute name="provide">true</xsl:attribute>
</created_by> <updated_by dt:type="string">
<xsl:attribute name="provide">true</xsl:attribute>
</updated_by> <updated_on dt:type="dateTime">
<xsl:attribute name="provide">true</xsl:attribute>
</updated_on> <territory_id> <xsl:attribute
name="idref"> <xsl:value-of
select="//USERAREA/TERRITORYID"/> </xsl:attribute>
</territory_id> <custom0 dt:type="string">
<xsl:value-of select="//USERAREA/CUSTOM0"/> </custom0>
<custom1 dt:type="string"> <xsl:value-of
select="//USERAREA/CUSTOM1"/> </custom1> <custom2
dt:type="string"> <xsl:value-of
select="//USERAREA/CUSTOM2"/> </custom2> <custom3
dt:type="string"> <xsl:value-of
select="//USERAREA/CUSTOM3"/> </custom3> <custom4
dt:type="string"> <xsl:value-of
select="//USERAREA/CUSTOM4"/> </custom4>
<company_id> <xsl:attribute name="idref">
<xsl:value-of select="//USERAREA/COMPANYID"/> <xsl:if
test="//USERAREA/COMPANYID=``">bisut000000000000001</xsl:if>
</xsl:attribute> </company_id> <addr1
dt:type="string" dt:size="80"> <xsl:value-of
select="//ADDRLINE[1]"/> </addr1> <addr2
dt:type="string" dt:size="80"> <xsl:value-of
select="//ADDRLINE[2]"/> </addr2> <city
dt:type="string" dt:size="50"> <xsl:value-of
select="//CITY"/> </city> <state dt:type="string"
dt:size="50"> <xsl:value-of
select="//ADDRESS/STATEPROVN"/> </state> <zip
dt:type="string" dt:size="80"> <xsl:value-of
select="//POSTALCODE"/> </zip> <country
dt:type="string" dt:size="80"> <xsl:value-of
select="//COUNTRY"/> </country> <email
dt:type="string"> <xsl:value-of select="//EMAIL"/>
</email> <employee_no dt:type="string" updateFlag="No"
dt:size="80"> <xsl:value-of select="//EMPLOYEENO"/>
<xsl:if test="//EMPLOYEENO=``"/> </employee_no>
<status dt:type="number"> <xsl:value-of
select="//USERAREA/STATUS"/> <xsl:if
test="//USERAREA/STATUS=``">Full Time</xsl:if>
</status> <password dt:type="string" updateFlag="No">
<xsl:value-of select="//USERAREA/PASSWORD"/> <xsl:if
test="//USERAREA/PASSWORD=``">412ABF98CDF3EF99</xsl:if>
</password> <username dt:type="string" updateFlag="No">
<xsl:value-of select="//USERAREA/USERNAME"/>
</username> <manager_id> <xsl:attribute
name="idref"> <xsl:value-of
select="//USERAREA/MANAGERID"/> </xsl:attribute>
</manager_id> <emp_type> <xsl:value-of
select="//EMPLOYEETYPE"/> <xsl:if
test="//EMPLOYEETYPE=``"/> </emp_type> <started_on
dt:type="dateTime"> <xsl:value-of
select="//USERAREA/STARTEDON"/> </started_on>
<terminated_on dt:type="dateTime"> <xsl:value-of
select="//USERAREA/TERMINATEDON"/> </terminated_on>
<location_id> <xsl:attribute name="idref">
<xsl:value-of select="//USERAREA/LOCATIONID"/> <!-- Change
value for default location_id --> <xsl:if
test="//USERAREA/LOCATIONID=``">locat000000000001000</xsl:if>
</xsl:attribute> </location_id> <max_discount
dt:type="number"> <xsl:value-of
select="//USERAREA/MAXDISCOUNT"/> <xsl:if
test="//USERAREA/MAXDISCOUNT=``">0</xsl:if>
</max_discount> <split dt:type="string">
<xsl:value-of select="//USERAREA/SPLIT"/> <xsl:if
test="//USERAREA/SPLIT=``">domin000000000000001</xsl:if>
</split> <rate dt:type="number"> <xsl:value-of
select="//USERAREA/RATE"/> <xsl:if
test="//USERAREA/RATE=``">0</xsl:if> </rate>
<quota dt:type="number"> <xsl:value-of
select="//USERAREA/QUOTA"/> <xsl:if
test="//USERAREA/QUOTA=``">0</xsl:if> </quota>
<jobtype_id> <xsl:attribute name="idref">
<xsl:value-of select="//USERAREA/JOBTYPEID"/>
</xsl:attribute> </jobtype_id> <ss_no
dt:type="string"> <xsl:value-of select="//USERAREA/SSNO"/>
<xsl:if test="//USERAREA/SSNO=``"/> </ss_no> <gender
dt:type="number"> <xsl:value-of
select="//USERAREA/GENDER"/> <xsl:if
test="//USERAREA/GENDER=``"/> </gender>
<home_domain> <xsl:attribute name="idref">
<xsl:value-of select="//USERAREA/HOMEDOMAIN"/> <xsl:if
test="//USERAREA/
HOMEDOMAIN=``">domin000000000000001</xsl:if>
</xsl:attribute> </home_domain>
<desired_job_type_id> <xsl:attribute name="idref">
<xsl:value-of select="//USERAREA/DESIREDJOBTYPEID"/>
</xsl:attribute> </desired_job_type_id>
<locale_id> <xsl:attribute name="idref">
<xsl:value-of select="//USERAREA/LOCALEID"/> <xsl:if
test="//USERAREA/LOCALEID=``">local000000000000001</xsl:if>
</xsl:attribute> </locale_id> <flags
dt:type="string"> <xsl:value-of
select="//USERAREA/FLAGS"/> <xsl:if
test="//USERAREA/FLAGS=``">0000000000</xsl:if>
</flags> <timezone_id> <xsl:attribute
name="idref"> <xsl:value-of select="//TIMEZONE"/> <!--
Change value for default timezone_id --> <xsl:if
test="//TIMEZONE=``">tzone000000000000008</xsl:if>
</xsl:attribute> </timezone_id> </SabaObject>
</SabaObjectSerialization> </xsl:for-each>
</xsl:template> </xsl:stylesheet>
[0775] The following is the equivalent Local Format document, a
generated Saba Person in Saba Canonical Format:
TABLE-US-00093 <SabaObjectSerialization
xmlns:dt="urn:w3-org:xmldatatypes"> <SabaObject
type="com.saba.busobj.SabaEmployee" status="existing"
id="http://bnemazie/interconnect/Saba/com.saba.interconnect.ObjectID
@170179/6805"> <title dt:type="string"
dt:size="10">MR.</title> <fname dt:type="string"
dt:size="25">testfirst</fname> <lname dt:type="string"
dt:size="25">testlast</lname> <mname dt:type="string"
dt:size="25"/> <homephone dt:type="string"
dt:size="25">972 580 7645</homephone> <workphone
dt:type="string" dt:size="25"/> <fax dt:type="string"
dt:size="25"/> <updated_by dt:type="string"
provide="true"/> <updated_on dt:type="dateTime"
provide="true"/> <territory_id idref=""/> <custom0
dt:type="string"/> <custom1 dt:type="string"/> <custom2
dt:type="string"/> <custom3 dt:type="string"/> <custom4
dt:type="string"/> <company_id
idref="bisut000000000000001"/> <addr1 dt:type="string"
dt:size="80">1213 addr1 1234</addr1> <addr2
dt:type="string" dt:size="80"/> <city dt:type="string"
dt:size="50">Irving</city> <state dt:type="string"
dt:size="50">TX</state> <zip dt:type="string"
dt:size="80">75038</zip> <country dt:type="string"
dt:size="80">US</country> <email dt:type="string"/>
<employee_no dt:type="string"
dt:size="80">185</employee_no> <status
dt:type="number">Full Time</status> <password
dt:type="string">412ABF98CDF3EF99</password> <username
dt:type="string">1093-202</username> <manager_id
idref=""/> <emp_type>Permanent</emp_type>
<started_on dt:type="dateTime">2000-07-24
00:00:00.0</started_on> <terminated_on
dt:type="dateTime"/> <location_id
idref="http://bnemazie/interconnect/Saba/com.saba.interconnect.Object
ID@cd92/6801"/> <max_discount
dt:type="number">0</max_discount> <split
dt:type="string">domin000000000000001</split> <rate
dt:type="number">0</rate> <quota
dt:type="number">0</quota> <jobtype_id
name="idref"/> <ss_no
dt:type="string">111-11-2222</ss_no> <gender
dt:type="number">0</gender> <home_domain
idref="domin000000000000001"/> <desired_job_type_id
idref=""/> <locale_id idref="local000000000000001"/>
<flags dt:type="string">0</flags> <timezone_id
idref="tzone000000000000008"/> </SabaObject>
</SabaObjectSerialization>
[0776] A SabaEmployee object is instantiated based on the canonical
XML document. This object is then saved, committing any changes to
the database.
[0777] The set of interconnect components is extensible so
additional functionality can be added over time. Adding a Searcher
component allows a site to be "exchange enabled"--able to share
catalog (or other) information with other sites. In this way users
can get results from searches that combine remote catalog offerings
with local catalog offerings. Adding a Purchaser component makes a
site "eCommerce enabled"--able to offer products for sale via an
automated interface. This enables learners who choose classes from
a catalog that has been shared on SabaNet to purchase them via
SabaNet. A Versioner component could offer the ability to
automatically upgrade to the latest version of the software or to
automatically purchase a license extension via a Licensor
component.
[0778] As described above the DeliveryService is a key component of
the Interconnect Backbone. Interconnect messages follow an
persistent asynchronous protocol. Messages are sent and received
with a message payload. Message payloads are opaque to the
DeliveryService, any object may be sent as a message payload. A
message recipient may reply to a message by constructing a reply
message from the original message and sending that reply as a
separate asynchronous message.
[0779] Message senders and recipients are responsible for
synchronizing their own messages. There are message ID fields in
the Message that may be used for this purpose. A Message contains
(1) The sender's InterconnectAddress (2) The recipient's
InterconnectAddress (3) The sender's credentials (4) A messageID
(5) A replyID (6) The message payload (an Object). Message senders
and recipients have an InterconnectAddress. This Address is managed
by the DeliveryService and contains (1) An Inbox identifier
(InboxID) assigned by the local DeliveryService (2) A String in URI
format identifying the service (mServiceURI), (3) An Object
identifying the associated User (mUser).
[0780] The InboxID is used by a DeliveryService for local message
routing. The URI identifies the specific software component and is
used to determine whether the InterconnectAddress is local or
remote. To send a message, an Interconnect client must: (1)
construct a Message for the given sender and recipient, (2) add the
message payload to the message, (3) set the message ID or the reply
ID if needed, (4) send the message using the DeliveryService's
IPostman interface. If the message is local it will be delivered
using the InboxID. If it is remote it will be forwarded to the
appropriate remote DeliveryService for delivery at that
location.
[0781] In order to use the DeliveryService, a connect must first be
made. Upon connection the DeliveryService assigns an InboxID that
is used internally for message routing and synchronization. This
InboxID is used in subsequent calls to the DeliveryService.
[0782] Once connected, messages may be sent or received from the
DeliveryService. There are two ways messages can be delivered
depending upon how the recipient registers. The recipient may Poll
for messages using IPostman.getMessage( ) or handle incoming
messages by implementing IRecipient.recieveMessage( ). The
IPostman.connect( ) method has an optional IRecipient parameter. If
a valid IRecipient is passed, incoming messages will be delivered
using that interface. In this case, behind the scenes, an
InboxAssistant is created in a separate thread to watch the Inbox
on behalf of the recipient. When a message is sent using
IPostman.sendMessage( ) the DeliveryService is responsible for
making sure that the message gets delivered to the appropriate
Inbox. If it cannot it must report or log an error.
[0783] In the simple case where a message recipient is in the same
installation as the sender, the DeliveryService will put the
message in the recipient's Inbox and be done with it. The message
will stay there until the recipient or the InboxAsistant takes it
out. When finished using the service, an Interconnect client may
disconnect from or release the Inbox. Disconnecting tells the
DeliveryService to maintain messages as the recipient intends to
reconnect at some later time. Releasing frees all DeliveryService
resources associated with the Inbox.
[0784] When the DeliveryService determines that message is destined
for a recipient in another Interconnect location, the local
DeliveryService must forward the message to its peer
DeliveryService at that location. The service identifier in the
message's recipient address is used to determine whether the
recipient is local or remote. This identifier is a URI with the
Host name (as returned by InetAddress.getLocalHost( )).getHostName(
)) and Interconnect service name. For example, a service named
"SabaAccessor" running on Saba host "flamenco" would have an URI of
the form "rmi://flamenco.saba.com/SabaWeb/Saba/Accessor".
[0785] The ServiceManager will look at the serviceURI and determine
whether the service in remote or local, if it is remote it will
resolve the address with it's remote peer.
[0786] Key to the design of the Interconnect is the notion of
pluggable transport protocols. To accommodate this, the Delivery
Service has 2 components (1) Delivery Service (2) Persistent
Message Manager. The Delivery Service writes messages to outbound
queues (if the message needs to be delivered to an external
system), the Persistent Message Manager polls out bound queues to
deliver the message to the host the message is intended for. The
persistent Message Manager has the uses pluggable transport
protocol. For implementing a protocol using RMI a class needs to be
written implementing IPMTransport. The Persistent Message Manager
(PMM) acts as the listener for receiving messages. Messages
received are put into inbound queues, the Delivery Service delivers
messages from the inbound queues to the Subscribers.
[0787] The rationale behind this separation is to allow for the
Interconnect DeliveryService/PMM to be deployed across a wide
variety of communication protocols. Supporting a new protocol
requires building a delivery transport that wraps that protocol.
The protocol wrappers are implemented as peers, and initiate and
accept connections, send and receive messages, terminate
gracefully, etc. For example, the following steps would be
performed to build a TCP/IP socket Interconnect Transport:
[0788] 1. Implement a interconnect listener/accepter
[0789] 2. Implement a client connection initiator
[0790] 3. marshal and write interconnect messages onto a socket
[0791] 4. read and unmarshal interconnect messages from a
socket
[0792] 5. implement the IPMTransport interface
[0793] A discussion of mapping Ids from one system to another using
the POID concept follows. When the Accessor receives a request to
export an object to a stream, it is passed a user object and a
platform ID (POID). In this case the POID is an ID associated with
the local object in this system. Generally this ID will be acquired
from another exported document or as a result of a Monitor event
however, some initial mappings may need to be provided to bootstrap
the system.
[0794] Given the POID, the Accessor looks up the local ID and the
document type in the Mapper. It is an error if there is no
associated local object. The Accessor then uses the document type
to look up the appropriate stylesheet, transformer and XMLHelper to
use during the accessing and transformation steps.
[0795] Using the AccessorReader for the configured system, the
local object is extracted into a stream in a system specific XML
format. The XML stream, the stylesheet and an output stream are
then passed to the transformer that writes the transformed XML to
the new stream. The transformed stream is then returned.
[0796] This is in the simple case where the XML to export contains
no external references to objects in the source system which are
not contained in the generated XML. In the more complicated case,
the XML stream is not fully self contained, i.e. it contains
references to objects that are not part of the XML stream. XML
however may contain the local Object Id of this Object, this Id is
meaning less outside this system. This Id needs to be replaced with
its POID.
[0797] The Accessor service needs to attempt to insure that all
unresolved references in the outbound XML document are represented
in the form of a POID. During export, the Accessor must find or
create a POID for each reference encountered and fix up those
object references in the XML stream. The Accessor will use the
Mapper to determine if the referenced object has an associated
POID. If a POID does not exist, one will be created and added to
the Mapper's tables.
[0798] Step by step on the Accessor side: [0799] 1. The Accessor
requests a document be exported by invoking the Accessor method:
[0800] Reader IAccessor.getObjectReader(UserObject user, POID poid)
[0801] 2. The Accessor looks up the local object ID from the
Mapper: [0802] LocalObjectID Mapper.getLocalID(POID platformID)
[0803] If there is no local ID an exception is raised. [0804] 3.
The Accessor looks up the document type from the Mapper: [0805]
String Mapper. getDocumentType (POID platformID) [0806] If there is
no document type, a default is used for the configured
AccessorReader. [0807] 4. The Accessor looks up the stylesheet,
IXMLHelper and ITransformer using the docType. [0808] 5. The
Accessor requests the object in XML format from the AccessorReader:
[0809] Reader IAccessorReader.extractObjectReader(LocalObjectID
localID, IXMLHelper helper) [0810] 6. The Accessor fixes up ID
references in the XML stream. It scans the stream looking for
foreign POIDs. [0811] 7. When a reference ID is encountered by the
Accessor, it resolves it to the POID using the Mapper. If no POID
exists one is created. The POID is written to the XML stream.
[0812] 8. An output stream is created and the document is
transformed: [0813] void ITransformer.transform(String stylesheet,
Reader in, Writer out)
[0814] When the Importer receives a request to import an object
from a stream, it is passed the stream, a user object, the document
type and a platform ID (POID). This POID is a foreign ID, created
when the document is exported from the source system.
[0815] The XML stream, a stylesheet and an output stream are passed
to the transformer and a new XML stream is produced. This new
stream is passed to a platform specific object that inserts it into
the system. On insert, a local object ID is created by the system
and returned.
[0816] When the local ID is returned to the Importer, the Importer
asks the Mapper to map the foreign POID to the Local Object. The
POID is then returned to the requester in the import status
reply.
[0817] This is in the simple case where the XML to import contains
no external references to objects in the source system which are
not resolved in the XML.
[0818] In the more complicated case, the XML document not fully
self contained. The document to import contains references to
objects that are not part of the XML document. The import service
attempts to resolve these references to insure the referential
integrity of the object being imported. During the transformation
phase, the Importer must resolve the foreign references to local
objects and fix up those object references in the XML stream.
[0819] The specified object may have already been imported in which
case there will be an entry in the local Mapper's foreign POID map.
The Importer asks the mapper to resolve the POID to a local object.
If this object has been mapped, a string representation of the
Object ID is used to replace the foreign POID in the XML
document.
[0820] In the case where the object has not been previously
imported the importer has two choices. Either it can fail and
report an error, or it can attempt to pull the object from the
foreign system. It is reasonable to make this a configurable option
and perhaps only support error reporting in the initial
release.
[0821] Step by step 1d mapping on Import: [0822] 1. The Subscriber
requests a document be imported by invoking the IImporter method:
[0823] ImportStatus IImporter.importObjectFromStream(POID poid,
UserObject user, Reader stream, String docType) [0824] 2. The
Importer looks up the stylesheet, IXMLHelper and ITransformer using
the docType. [0825] 3. An output stream is created and the document
is transformed: [0826] void ITransformer.transform(String
stylesheet, Reader in, Writer out) [0827] 4. The Importer fixes up
foreign ID references in the XML stream. It scans the stream
looking for foreign POIDs. [0828] 5. When a foreign ID is
encountered by the Importer, it resolves it to the local ID using
its Mapper. The local ID is written to the XML stream. [0829]
LocalObjectID Mapper.resolveForeignObject(POID foreignID) [0830] 6.
The fixed-up XML stream is passed to the ImporterWriter to insert
into the system. [0831] LocalObjectID insertObjectFromStream(Reader
in, IXMLHelper helper) [0832] 7. Map the new local ID to the
original foreign POID passed with the import request. [0833] void
Mapper.mapForeignObject(POID foreignID, LocalObjectID localID)
[0834] So far the discussion has been around the
Interconnect/Connector framework. The following discusses Connector
Specific plug ins, and defines the specific components for each
connector. Taking Saba Connector as an example: [0835] a.
SabaChangeManager--This class extends the Change Manager, starts a
thread that polls the database for changes. Once a change is
detected the change is passed over to the Monitor for further
processing. This class has the specific logic to poll Saba
database. [0836] b. SabaImporterWriter--This class extends the
ImporterWriter and has the logic to import Objects in Local format
(SCF) into Saba system. [0837] c. SabaAccessorReader--This class
extends the AccessorReader and has the specific logic to retrieve
objects from Saba system in local format.
[0838] Every new connector has to implement these 3 classes to work
with application connecting. Extending this we have
sapChangeManager, sapImporterWriter and sapAccessorReader.
Information Server
[0839] The present invention relates to a novel information
distributor method and apparatus. The present invention can provide
services for consolidating, analyzing, and delivering information
that is personalized, relevant, and needed.
[0840] It employs metadata-based profiles to match information with
users. User profiles may include skill competencies and gaps, roles
and responsibilities, interests and career goals.
[0841] The Platform services provides the interface and
infrastructure for building agents that work in concert to decide
what information is delivered, when it is delivered, and how it is
delivered.
[0842] The platform services integrate with the Platform
Interconnect Server to work across different networks and disparate
information systems. This allows users to receive information from
a variety of sources and locations via a single, consistent
interface.
[0843] The present invention uses an Information Distributor
Developer's Kit (IDK) to be used by software application developers
of ordinary skill in the art.
[0844] The platform of the present invention identifies and fills
information gaps across the corporate value chain. IDK provides the
infrastructure and core functionality to find and deliver relevant
and targeted information. In an embodiment, the IDK enables more
sophisticated querying and matching functionality than in the prior
art and serves as the technology underpinnings for a stand-alone
Enterprise Information Portal (EIP) solution.
[0845] For more information on RDF, refer to the W3C home page,
incorporated by reference in its entirety, at the URL
www.w3.org/RDF/ and formal specification located at URL
www.w3.org/TR/REC-rdf-syntax/.
[0846] The above sources of information are incorporated by
reference in their entireties.
[0847] FIG. 11 shows a structural overview of an IDK 1100 of the
present invention. IDK 1100 is associated with a language 1102,
such as RDF, for representing web metadata, a language for querying
web metadata, and a set of APIs 1104 for defining information
services based on what data is used, when and how a match is
performed, and what is done with the results.
[0848] FIG. 12 shows a functional overview of an Information
Distributor 1201 of the present invention. IDK 1100 can annotate
and match broad resources 1200, support diverse sources,
conditions, and delivery options 1202, provide an easy migration
path 1204, and leverage open standards 1206.
[0849] In an embodiment of the invention, Information Distributor
1201 provides a flexible mechanism for annotating and matching web
resources 1200. Information Distributor 1201 can locate and deliver
a wide variety of resources, from web pages to Business Objects.
Information Distributor 1201 also supports a wide variety of
descriptive information required by business applications, from
standard web metadata to catalog information to skills and
competencies.
[0850] Information Distributor 1201 also supports a broad variety
of information sources, match conditions, and delivery mechanisms
1202. Information Distributor 1201 generates matches under a
variety of circumstances and supports a variety of options for
delivering match results.
[0851] Information Distributor 1201 provides an easy migration path
1204. A software developer of ordinary skill in the art can write
queries using a combination of Java code and SQL. IDK provides
equivalent functionality using a higher-level languages for
representing and querying data and simpler programming APIs.
Information Distributor 1201 also leverages open standards 1206 by
supporting industry standards such as RDF and XML. Support for
industry standards helps ensure the availability of third-party
tools that interoperate with IDK and increases the set of data and
information on which IDK can act.
[0852] In an embodiment of the invention, Information Distributor
1201 can determine if a new software developer has just joined a
new project. If one of the skills required for the new software
developer's new assignment is knowledge of XML, then upon joining
the project, Information Distributor 1201 automatically send an
email to the new software developer containing information about
the company's standard "Introduction to XML" course.
[0853] In an embodiment of the invention, Information Distributor
1201 can keep a development manager informed about the status of
the other development groups in his division. As part of his custom
home page provided by the corporate portal, he can view a list of
the most recent updates submitted by each development manager, and
call up each report in his web browser.
[0854] In an embodiment of the invention, Information Distributor
1201 can detect when an affiliated training provider has made
available a new advanced class in Java. Information Distributor
1201 sends email to all advanced and expert Java programmers in the
company announcing the availability of this class.
[0855] In an embodiment of the invention, Information Distributor
1201 can detect when the HR department institutes a new approval
practice for all new hires. Information Distributor 1201 assures
all hiring managers in the company receive a new entry in the
Corporate Information channel that explains the policy change.
[0856] If an updated price list for a region is generated,
Information Distributor 1201 sends an email containing the new
price information to all dealers in that region.
[0857] If an employee has a change in his family status, such as if
the employee has a baby, the next time the employee views the HR
department's benefits page in his web browser, the Information
Distributor assures customized plan and deductible information
appears that is appropriate for his new family status.
[0858] Referring again to FIG. 11, in an embodiment, the
Information Distributor adopts a new standard for web metadata and
its definition of a high-level language 1102 for querying this
metadata.
[0859] Metadata is structured information about information, and is
used to identify, categorize, and locate resources of interest.
Resource Description Format (RDF) is a new, XML-based standard for
associating arbitrary metadata with any web resource. It can be
used to describe resources ranging from a course catalog on the WWW
to a business object representing a client.
[0860] In an embodiment a language used to query web metadata 1102
may be RDF Query Language (RQL), an XML-based query language for
writing queries against RDF data. It can represent both simple and
complex queries, and can also accommodate metadata matching, where
a metadata description can be part of the query. For example, this
allows a particular employee's complete skills gap--expressed as an
RDF description--to be used in a query to locate classes that fill
the gap.
[0861] FIG. 13 shows an exemplary view of APIs 1104 associated with
the Information Distributor. In an embodiment, the Information
Distributor partitions information matching and delivery issues
into three areas, each addressed by a distinct type of agent,
Import Agents 1300, Match Agents 1302, and Delivery Agents 1304.
The combination of Import Agent 1300, Match Agents 1302, and
Delivery Agents 1304 is a novel combination of the present
invention.
[0862] Import Agents 1300 create and import the RDF descriptions
used by IDK. Import Agents 1300 can generate metadata from a
variety of sources, from existing web pages and business objects to
content management systems to enterprise applications.
[0863] Match Agents 1302 determine what matches and queries occur
under what conditions. Match Agents 1302 can be triggered by a
request to a web or application server, by specific events, or on a
regularly scheduled basis. A Match Agent 1302 also specifies the
RQL and any input metadata to use as the metadata query.
[0864] Delivery Agents 1304 dispatch the results of a query or
match. In an embodiment, Delivery Agents 1304 integrate with a
variety of delivery mechanisms, from web page generation and XML
datagrams to email and event messaging systems.
[0865] In an embodiment of the invention, FIG. 14 shows an
exemplary view of using Information Distributor or IDK 1100. A
software developer of ordinary skill in the art can use IDK to
query objects 1400 or to implement custom delivery service 1402. In
an embodiment, Query Objects 1400 may be used similarly to today's
finder methods, that is, a high-level mechanism to query SABA
business objects, but using and requiring knowledge of RDF and
RQL.
[0866] FIG. 15 shows an exemplary overview of Query Objects 1400.
The invention, through a user associated with the invention, such
as but not limited to a software developer of ordinary skill in the
art, defines RDF Metadata Mappings 1500 for the objects and
metadata of interest. Then, the invention Authors An Import Agent
1502 to capture this metadata. The invention may then Author An RQL
Document 1504 to query this metadata and author a Match Agent to
Perform the Query 1506 and a Delivery Agent to act on the query
results.
[0867] FIG. 16 shows an exemplary overview of Implement Custom
Delivery Service 1402. The invention, through a user, such as but
not limited to a software developer of ordinary skill in the art,
may use the invention's IDK to novelly Implement a Custom
Information Delivery Service 1402, using RDF, RQL, and the full IDK
interface. In an embodiment, the invention Defines RDF Metadata
Mappings 1600 for the objects and metadata of interest. The
invention Authors An Import Agent 1601 to capture this metadata.
The system and method of the present invention then Authors An RQL
Document 1602 to query this metadata. The invention then Authors a
Match Agent 1604 to perform the query. and Authors a Delivery Agent
1606 to dispatch the query results. The invention then Integrates
All Agents 1608, including the import agent, the match agent, and
the delivery agent, into the existing system.
[0868] In an embodiment of the invention, Information Distributor
(IDK) is a Software Development Kit delivered as part of Platform
4.0. It provides the infrastructure and basic functionality needed
to build and customize the Enterprise Information Portal.
[0869] IDK provides the infrastructure and services to perform
metadata-based queries. Unlike traditional text-based search
engines, in an embodiment the IDK operates solely on descriptive
data about resources, rather than the resources themselves.
[0870] In an exemplary embodiment of the invention, referring again
to FIG. 13, IDK defines interfaces for metadata generation
(Importers or Import Agents 1300) and matching (Resolvers or Match
Agents 1302) and for delivering query results (Dispatchers or
Delivery Agents 1304). Combinations of these three services allow
the Information Distributor to interoperate with a variety of
enterprise systems and to service queries in a broad range of
application domains.
[0871] In an embodiment, a portal server may be delivered using
IDK.
[0872] Import Agents are responsible for consolidating a variety of
information sources. Importers integrate with various external
systems, analyze the descriptive data about specific resources in
the system, and import this data into a custom RDF database.
Exemplary information sources include internal email systems and
Intranets, SABA EMS, ERP systems, and the World Wide Web.
[0873] Common tasks supported by Import Agents include:
[0874] Executing batch imports
[0875] Scheduling imports at regular intervals
[0876] Analyzing and translating metadata formats
[0877] Specifying a target database
[0878] Integrating with SABA Interconnect
[0879] Match Agents are responsible for matching between
information resources and user profiles. Match Agents execute at
regular intervals or in response to specific requests. They perform
intelligent comparisons between metadata descriptions of imported
resources and user profiles. These comparisons return a set of
information resources as the match result.
[0880] Because they act on detailed user profiles, Match Agents can
function as personal agents, identifying those resources most
relevant to a user's job, interests, or objectives. For example,
they can determine that a user requires knowledge of a specific
technology for a new job assignment, and deliver suggestions for
classes covering that technology.
[0881] Because they match against categorized metadata, Resolvers
can return more accurate and meaningful results than is possible
with traditional text-based searches. For example, Match Agents can
return only documents that have been updated within the last week.
Or they can distinguish between articles about an individual and
articles written by the individual.
[0882] Delivery Agents are responsible for delivering the results
of a match to the correct recipients in the appropriate fashion.
Delivery Agents integrate with various delivery mechanisms,
delivering either pointers to the match results or the actual
information itself. Typical delivery vehicles include e-mail, web
servers, and enterprise portals.
[0883] Common tasks supported by Delivery Agents include:
[0884] Delivering results immediately upon availability
[0885] Delivering results at delayed or batched intervals
[0886] Integrating with SABA Interconnect
[0887] In an embodiment, the final system and method of the present
invention may be capable of scaling to handle enterprise-wide
document databases. An initial prototype that may be delivered is
capable of demonstrating the proof-of-concept without exhibiting
the scalability of the final system.
[0888] The IDK provides a flexible mechanism for describing and
comparing a wide variety of resources. The actual data being
compared may vary widely among applications, ranging from
competencies and skills for gap analysis to document summaries and
reviews for web content. Yet the actual operations involved in
determining a match tend towards a small set, text and numeric
comparisons and basic Boolean logic. Thus, the IDK needs to casts a
broad variety of properties into a consistent format for purposes
of comparison.
[0889] In an embodiment, the invention employs the Resource
Description Format (RDF), the World Wide Web Consortium's standard
for web metadata. It meets the above requirements because it is
designed to support a wide range of different applications,
expressing them all in a consistent attribute property/value
format. The format also allows the definition of standard
vocabularies for specific application domains, and the mixing and
matching of these vocabularies to describe a resource. The format
has a web-centric design, employing URLs to describe any form of
web resource and XML to serialize its data graphs and is seeing
slow but steady adoption in a variety of domains, from electronic
documents and on-line learning to news stories and business
cards.
[0890] By choosing RDF as the Information Distributor's standard
metadata format, the invention makes it easy and efficient for
customers to work with the system because they can turn to external
sources for training and documentation, can use third party tools
for defining their metadata, and are more likely to already have or
be able to find developers familiar with RDF. Furthermore, as RDF
is used for more domains, the Information Distributor can be
applied to an ever-increasing amount of content.
[0891] RDF is essentially a model for representing attribute/value
pairs as a directed labeled graph. It consists of statements that
pair a web resource (anything identified by a URL) with a property
and a value. At its core, IDK provides a flexible mechanism for
comparing these attribute/value pairs and taking action upon the
comparison results.
[0892] The Match Agent operates by comparing one RDF description to
the full set of RDF descriptions in a specified database. Because
of the variety and flexibility of RDF descriptions, additional
instructions are required to specify how the match is performed.
This is the function of the match template.
[0893] Match templates specify certain fields as belonging to a
target RDF file. In an embodiment, the target is a file that is
provided along with the match template to customize the search, for
example, to perform a predefined search against a specific
individual's description. Match templates may also be written to
perform a fixed search, in which case there is no target RDF file.
Merging a match template with a target RDF file produces an RDF
query.
[0894] Match templates can specify the following aspects of a
query:
[0895] The specific properties to be compared.
[0896] The comparison operation (=, !=, <, >)
[0897] Boolean operators (AND, OR, NOT)
[0898] A set of comparison functions, including: [0899] like (text
matching) [0900] latest (most recent date)
[0901] container operation: contains, first, etc.
[0902] In an embodiment, match templates are: [0903] easy to create
and edit by hand [0904] conducive to creation by an authoring tool
[0905] easy to parse
[0906] In an embodiment, the complete syntax and specification used
by match templates is defined by the RDF Query Language
Specification, described below.
[0907] RDF-based Match Templates are unique and never before
contemplated by the prior art. The combination of a match template
and a target RDF file can produce an RDF Query. In an embodiment of
the invention, the core of the Information Distributor is a RDF
Query engine that performs a query on one or more RDF databases,
then returns a set of resources that satisfy the query.
[0908] In an embodiment of the invention, a client may use the
Information Distributor SDK by performing the following exemplary
method steps: [0909] 1. Write an Import Agent that implements the
ImportAgent interface and employs the MR.importRDF( ) method.
[0910] 2. Write a Match Agent that implements the MatchAgent
interface and employs the MR.match( ) method. [0911] 3. Write a
Delivery Agent that implements the DeliveryAgent interface. [0912]
4. Create a new instance of an MR (Metadata Repository). [0913] 5.
Write code to create specific instances of the above agents and set
them into motion.
[0914] In an embodiment of the invention, an ImportAgent is
responsible for delivering metadata in RDF format to a Metadata
Repository. Specific Import Agents may interface with a particular
source of metadata, translate that metadata into RDF, and use the
MR.importRDF( ) method to import that RDF. Import Agents may
register with the Event Manager to perform imports in response to
particular events. In an embodiment, the Import Agent has the sole
responsibility for performing the metadata translation. In an
embodiment of the invention, the invention provides utility
routines that assist with translating various common metadata
formats or serve to automatically generate metadata. In an
embodiment, the invention provides additional utility functions for
interfacing with the Event Manager or scheduling batch imports.
[0915] In an embodiment of the invention, a MatchAgent is
responsible for performing a metadata match. Specific Match Agents
may create a Match Descriptor and pass it to a specific MR to
perform a match. Match Agents may perform matches in response to
particular events. In an embodiment of the invention, distributed
queries may be performed across multiple MR.
[0916] Match Agents may employ a utility class called
MatchDescriptor that captures all information needed for a metadata
query or match template.
[0917] This class is defined as follows:
TABLE-US-00094 public class MatchDescriptor { /** MatchDescriptor
constructor. * * @param aTemplate Contents of a match template. *
@param aTarget URI of a target RDF file. May be NULL if the match *
template describes a fixed search. * @param aHandler MatchHandler
to operate on the match results. */ public MatchDescriptor(String
aTemplate, String aTarget, MatchHandler aHandler) } /*
MatchDescriptor */
[0918] In an embodiment of the invention, a Delivery Agent is
responsible for delivering the result of a metadata match. Delivery
Agents implement the following Java interface:
TABLE-US-00095 public interface DeliveryAgent { /** Deliver the
results of a match. * @param mrs A MatchResultSet containing the
match results. * @exception DeliveryException Thrown when delivery
fails. */ public void deliver(MatchResultSet mrs) throws
DeliveryException; } /* DeliveryAgent */
[0919] Delivery Agents use a utility class called MatchResultSet
that contains the result of a metadata match. A MatchResultSet
contains a Vector of RDFResource objects, a class containing a URI
for each resource returned by a metadata match, as well as
additional, optional properties. The MatchResultSet class is
defined as follows:
TABLE-US-00096 public class MatchResultSet { /** * Set the results.
* @param theResults Vector of RDFDescription objects. */ public
void setResults(Vector theResults) /** * Return an Enumeration of
match results. * @return Enumeration of RDFDescription objects */
public Enumeration getResults( )
[0920] In an embodiment of the invention, the contents of the
MatchResultSet may be serialized as a simple XML document. One RDF
Description element may be associated with each result. Using RDF
permits the invention to deliver additional properties that may be
useful to the consumer of the MatchResultSet, such as properties
taken from the source RDF Description or additional properties
returned by the Match Engine.
[0921] The following is pseudocode for a sample XML result:
TABLE-US-00097 * * <resultset> * <Description about =
"http://sabainet/devo/status/sb11_12_99.html"> *
<dc:Title>Weekly Status of Project Sweet
Baboo</dc:Title> * </Description> * <Description
about="http://sabainet/devo/status/lp11_08_99.html"> *
<dc:Title>Weekly Status of Project Beethoven</dc:Title>
* </Description> * </resultset> *
[0922] In an embodiment of the invention, a MR (Metadata
Repository) is an interface that any Metadata Repository must
implement.
[0923] The following is the interface for a MR:
TABLE-US-00098 public interface MR { /* The import methods are used
to insert RDF metadata into the MR. */ /** Import an RDF document
specified in a URI. * @param uri URI to the RDF file. * @exception
ImportException Thrown when import fails. */ public void
importRDF(String uri) throws ImportException; /** Import an RDF
document specified in a Reader. * * The "key" parameter serves as a
unique identifier; * when RDF is re-imported with the same key
value, it replaces the previous * import. The "key" value is most
typically the URI. * * @param r Reader containing RDF text. *
@param key Unique identifier for this RDF source. * @exception
ImportException Thrown when import fails. */ public void
importRDF(Reader r, String key) throws ImportException; /** Perform
a metadata match. This involves the following steps: * * <ol>
* <li>Extracting the contents of the MatchDescriptor *
<li>Generating a MatchResultSet * <li>Passing the
MatchResultSet to the MatchHandler contained * in the
MatchDescriptor * </ol> * * @param md MatchDescriptor fully
describing the match to perform. * @exception MatchException Thrown
when match fails. */ public abstract void match(MatchDescriptor md)
throws MatchException; /** * Retrieve a named property of a
specific resource. Returns null if * the specified property does
not exist. * * @param resource URI of resource. * @param namespace
URI of namespace; null if no namespace is specified. * @param
property Property name. * @return Property value. */ public String
getProperty(String resource, String namespace, String property)
throws MatchException; } /* MR */ "
[0924] In an embodiment of the invention, RDF Query Language (RQL)
is an easy-to-learn, easy-to-author language for querying
collections of RDF documents. It is designed to support the full
functionality required by Information Distributor.
[0925] RQL is an XML application. An RQL document may consist of a
single Select element containing a single Condition. A condition
may be either a direct operation on a single property, or a Boolean
grouping operation, which can in turn contain further Conditions.
RQL can define a number of built-in comparison operations; it also
allows comparisons against variables extracted from an accompanying
target RDF file.
[0926] Each Element is described in detail below.
RDFQuery
[0927] RDFQuery is the root element of an RQL document. It must
contain a single Select element.
Container
[0928] A container is a grouping property value. Containers can be
Bags, unordered lists of resources or literals, Sequences, ordered
lists of resources of literals, or Alternatives, distinct
choices.
Literal
[0929] A literal is a property value that is a simple string
(including possibly XML markup) or other primitive datatype.
Property
[0930] A property is a specific characteristic or attribute used to
describe a resource. The RDF model may contain Statements, which
are a named property and value assigned to a specific resource.
Resource
[0931] A resource may be anything described by an RDF expression. A
resource is identified by a URI.
Select
[0932] The Select element defines the properties that are returned
by an RDF Query. The result of an RDF Query is itself an RDF
document; it is the set of RDF Description elements that satisfy
the query. By default, only the Resource URI is returned (as an
about, aboutEach, or aboutEachPrefix attribute of the Description
element). The properties attribute is used to define additional
properties to be returned. It is a space-separated list of all
property names to be returned. The initial implementation only
allows literal, first-level property values to be returned; that
is, containers, nested properties, and resources are not
supported.
[0933] Within the Information Distributor, the returned RDF
elements are wrapped in a MatchResultSet object for convenient
manipulation from Java.
Condition
[0934] The Condition element defines a condition that RDF
Descriptions must satisfy to be returned. Conditions are either
simple, in which case they specify a Property/Value/Operation
triple, or complex, in which case they contain one of the boolean
operators. The simple Conditions simply obtain a property and
compare it to the value using the specified operation. Operations
are defined for literal properties and container properties.
[0935] A Property/Value/Operation triple can also contain a nested
Condition; this allows querying against reified statements, or
statements about statements. Refer to Query 11 for an example.
And, Or, Not
[0936] The Boolean operators perform logical operations on one or
more conditions. Not negates the value of a single conditions,
while And Or perform logical operations on two or more
conditions.
[0937] Because many RQL operations operate on containers, there is
an "applies" attribute that determines the behavior of grouping
operators on containers. When "applies=within" (the default),
operations within a grouping condition must apply to the same value
within a container. For example, this allows specifying conditions
on two elements within the same container element. When
"applies=across," conditions need not apply to the same value in
the container.
[0938] Notice that the Not operator returns all resources that do
not satisfy the specified condition, which is not the same as
resources that satisfy the negation of the condition. Refer to
Query 3 for an example of this distinction.
Property
[0939] The Property element identifies a specific, named property
of a Resource. Its contents identify the named property (also known
as the predicate). Its contents can be a nested property, that is,
multiple property names separated by forward slashes. This syntax
may navigate over multiple properties, where each property value is
a resource with its own properties. This may be the same syntax
used by RDF Query's "path" attribute for nested queries.
[0940] As a convenience, it may not be necessary to specify
Container-related properties as part of the path, that is, Bag,
Seq, Alt, and li elements are automatically navigated past.
Value
[0941] The Value element defines the value against which a specific
property is compared. It can contain a literal string, which is
compared directly against literal properties, or against a
container property using one of the container operations.
[0942] In a Match Template, the Value element may also contain a
Variable element, which indicates that the value is extracted from
the target RDF file.
[0943] The Value element can also specify a dt:dtype attribute that
specifies the datatype of the value. The only datatype that must be
explicitly specified is "dateTime," which indicates that a date
comparison is to be performed on a ISO 8601 date. Date values can
also incorporate the "sysdate" keyword to indicate an operation
based on the current date. Refer to Query 12 for an example.
Operation
[0944] The Operation element defines how the comparison is
performed. RQL supports a number of predefined operations.
[0945] Literal operations operate on literal values. They
include:
[0946] equals (=) performs an exact text match or numeric
comparison. It will also match a resource URI.
[0947] notEquals (!=) tests for inequality.
[0948] greaterThan (>) performs the numeric comparison.
[0949] lessThan (<) performs the numeric comparison.
[0950] greaterThanOrEquals (>=) performs the numeric
comparison.
[0951] lessThanOrEquals (<=) performs the numeric
comparison.
[0952] like performs a substring text match.
[0953] We provide verbose forms of the various arithmetic
operations for readability; this is because characters such as
<require escaping within XML, which can become unwieldy.
[0954] Container operations operate on container values (Bags,
Sequences, and Alternatives). They include:
[0955] contains
[0956] first
[0957] last
[0958] index(n)
[0959] sum
[0960] count
[0961] Notice that the first, last, and index( ) operations are
only meaningful for Sequences.
[0962] Multiple Operations can be specified in a single Condition;
this is useful for queries that combine container and literal
operations, such as a numeric comparison on the first entry of a
Sequence. There are also two implicit shortcuts: [0963] 1. A
literal operation on a container first performs an implicit
"contains." [0964] 2. A container operation without a further
literal operation always performs an implicit "equals."
Variable
[0965] The Variable element defines a substitution variable. It
contains a Property element, and is used to obtain a literal value
from a target RDF file.
[0966] Variable elements are only found in Match Template.
Namespaces
[0967] RQL supports namespace declarations as attributes of any
element. It then applies these namespaces to property values. This
means that property values can use namespaces prefixes. See the
examples section for several illustrations of this technique.
Notice also that this is an uncommon use of namespaces; rather than
applying namespace declarations to element and attribute names, it
is applied to the text within the document.
[0968] Notice also that for variables, the corresponding namespace
declarations must exist in the target RDF file, as opposed to the
RQL file itself.
[0969] Document Type Definition (DTD) for RQL Documents
TABLE-US-00099 <!-- An RQL document contains a single Select
element. --> <!ELEMENT rdfquery (select)> <!-- Each
Select clause contains a single Condition. The "properties"
attribute defines the information to return as part of the result
set. Note that the URI of each matching Resource is always
returned. --> <!ELEMENT select (condition)> <!ATTLIST
select properties NMTOKENS #IMPLIED> <!-- A Condition can
either directly contain an operation, or contain a boolean grouping
operator --> <!ELEMENT condition ( (operation+, property,
value, condition?) | and | or | not)> <!-- Boolean grouping
operators --> <!ELEMENT and (condition, condition+) >
<!-- the "applies" attribute determines whether or not the
condition within a grouping operation must all apply to the same
value in a Collection. --> <!ATTLIST and applies (within |
across) "within"> <!ELEMENT or (condition, condition+) >
<!ATTLIST or applies (within | across) "within"> <!ELEMENT
not (condition) > <!-- An operation defines how to compare a
property to a value --> <!ELEMENT operation (#PCDATA) >
<!-- Property identifies a specific property in an RDF file. For
container objects, any children are acceptable matches, and
intervening Container and Description tags are automatically
navigated past. --> <!ELEMENT property (#PCDATA)> <!--
A value defines the value to which a property is compared. It is
either a constant String, or a Variable whose value comes from a
target RDF file. --> <!ELEMENT value (#PCDATA | variable)*
> <!-- The value element can have a dt:type attribute
specifying its datatype --> <!ATTLIST value dt:type NMTOKEN
#IMPLIED> <!-- A variable indicates a property value obtained
from a target RDF file; it contains a Property element. -->
<!ELEMENT variable (property)>
[0970] The following are exemplary embodiments of RQL documents.
The example queries may all use the following source RDF
document:
TABLE-US-00100 <?xml version="1.0"?> <rdf:RDF
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax- ns#"
xmlns:hr="http://www.saba.com/hr#"
xmlns:ewp="http://www.saba.com/ewp#"
xmlns:ems="http://www.saba.com/ems#"
xmlns:vCard="http://imc.org/vCard/3.0#"> <rdf:Description
about="http:/www.saba.com/people/sally_brown"> <vCard:N
rdf:parseType="Resource">
<vCard:Family>Brown</vCard:Family>
<vCard:Given>Sally</vCard:Given> </vCard:N>
<vCard:UID>987-65-4320</vCard:UID>
<vCard:ROLE>Manager</vCard:ROLE> <vCard:ORG
rdf:parseType="Resource">
<vCard:Orgname>Development</vCard:Orgname>
</vCard:ORG> <hr:Location>HQ</hr:Location>
<hr:Reports> <rdf:Bag> <rdf:li
resource="http://www.saba.com/people/Snoopy"/> <rdf:li
resource="http://www.saba.com/people/Woodstock"/>
</rdf:Bag> </hr:Reports> <ewp:competency>
<rdf:Bag> <rdf:li>Java.Expert</rdf:li>
<rdf:li>XML.Proficient</rdf:li> </rdf:Bag>
</ewp:competency> <ewp:Interests> <rdf:Bag>
<rdf:li>Java</rdf:li> <rdf:li>EJB</rdf:li>
<rdf:li>COM</rdf:li> </rdf:Bag>
</ewp:Interests> <ems:Training_Locations>
<rdf:Seq> <rdf:li>San Francisco, CA</rdf:li>
<rdf:li>San Jose, CA</rdf:li> <rdf:li>Los
Angeles, CA</rdf:li> <rdf:li>Denver, CO</rdf:li>
</rdf:Seq> </ems:Training_Locations>
</rdf:Description> <rdf:Description
about="http:/www.saba.com/people/sally_brown" bagID="ID001">
<ewp:competency>EJB.Advanced</ewp:competency>
</rdf:Description> <rdf:Description aboutEach="#ID001">
<ewp:attained>1999-02-25</ewp:attained>
<ewp:provider
rdf:resource="http://www.sabanet/AllAboutJava/"/>
<ewp:details> <rdf:Bag>
<rdf:li>CBT</rdf:li>
<rdf:li>evaluation</rdf:li> </rdf:Bag>
</ewp:details> </rdf:Description> </rdf:RDF>
[0971] The following exemplary query ("Query 1") associated with
the above source RDF document selects all managers in a
department:
TABLE-US-00101 <?xml version="1.0"?> <!DOCTYPE rdfquery
SYSTEM "rql.dtd"> <rdfquery> <select> <condition
xmlns:vCard="http://imc.org/vCard/3.0#">
<operation>equals</operation>
<property>vCard:ROLE</property>
<value>Manager</value> </condition>
</select> </rdfquery>
[0972] The following exemplary query ("Query 2") selects all
developers in a department, or everyone in a development
organization:
TABLE-US-00102 <?xml version="1.0"?> <!DOCTYPE rdfquery
SYSTEM "rql.dtd"> <rdfquery> <select> <condition
xmlns:vCard="http://imc.org/vCard/3.0#">
<operation>equals</operation>
<property>vCard:ORG/vCard:ORGNAME</property>
<value>Development</value> </condition>
</select> </rdfquery>
[0973] The following exemplary query ("Query 3") selects the name
and division of everyone who is not located at a headquarter
location:
TABLE-US-00103 <?xml version="1.0"?> <!DOCTYPE rdfquery
SYSTEM "rql.dtd"> <rdfquery> <select
properties="vCard:FNAME vCard:ORG"
xmlns:vCard="http://imc.org/vCard/3.0#"
xmlns:hr="http://www.saba.com/hr#"> <condition>
<operation>notEquals</operation>
<property>hr:Location</property>
<value>HQ</value> </condition> </select>
</rdfquery>
[0974] The following exemplary query ("Query 4") returns slightly
different results, in that it also returns all resources that do
not have an hr:Location property:
TABLE-US-00104 <rdfquery> <select properties="vCard:FNAME
vCard:ORG" xmlns:vCard="http://imc.org/vCard/3.0#"
xmlns:hr="http://www.saba.com/hr#"> <condition>
<not> <condition>
<operation>equals</operation>
<property>hr:Location</property>
<value>HQ</value> <condition> </not>
</condition> </select> </rdfquery>
[0975] The following exemplary query ("Query 5") finds an employee
named "Sally Brown":
TABLE-US-00105 <?xml version="1.0"?> <!DOCTYPE rdfquery
SYSTEM "rql.dtd"> <rdfquery> <select
xmlns:vCard="http://imc.org/vCard/3.0#"> <condition>
<and applies="within"> <condition>
<operation>equals</operation>
<property>vCard:N/vCard:Family</property>
<value>Brown</value> <condition>
<condition> <operation>equals</operation>
<property>vCard:N/vCard:Given</property>
<value>Sally</value> </condition> </and>
<condition> </select> </rdfquery>
[0976] The following exemplary query ("Query 6") selects everyone
with a competency of "Advanced" in EJB:
TABLE-US-00106 <?xml version="1.0"?> <!DOCTYPE rdfquery
SYSTEM "rql.dtd"> <rdfquery> <select> <condition
xmlns:ewp="http://www.saba.com/ewp#">
<operation>contains</operation>
<property>ewp:Competency</property>
<value>EJB.Advanced</value> </condition>
</select> </rdfquery>
[0977] The following exemplary query ("Query 7") selects everyone
who will train in San Francisco:
TABLE-US-00107 <?xml version="1.0"?> <!DOCTYPE rdfquery
SYSTEM "rql.dtd"> <rdfquery> <select> <condition
xmlns:ems="http://www.saba.com/ems#">
<operation>contains</operation>
<property>ems:Training_Locations</property>
<value>San Francisco, CA</value> </condition>
</select> </rdfquery>
[0978] The following exemplary query ("Query 8") selects everyone
will train in some location in California and return to that
location:
TABLE-US-00108 <?xml version="1.0"?> <!DOCTYPE rdfquery
SYSTEM "rql.dtd"> <rdfquery> <select
properties="ems:Training_Locations"
xmlns:ems="http://www.saba.com/ems#"> <condition>
<operation>like</operation>
<property>ems:Training_Locations</property>
<value>CA</value> </condition> </select>
</rdfquery>
[0979] The following exemplary query ("Query 9") selects everyone
whose first choice of training location is anywhere in
California:
TABLE-US-00109 <?xml version="1.0"?> <!DOCTYPE rdfquery
SYSTEM "rql.dtd"> <rdfquery> <select
properties="ems:Training_Locations"
xmlns:ems="http://www.saba.com/ems#"> <condition>
<operation>index(1)</operation>
<operation>like</operation>
<property>ems:Training_Locations</property>
<value>CA</value> </condition> </select>
</rdfquery>
[0980] The following exemplary query ("Query 10") finds the manager
of an employee named "Woodstock":
TABLE-US-00110 <?xml version="1.0"?> <!DOCTYPE rdfquery
SYSTEM "rql.dtd"> <rdfquery> <select> <condition
xmlns:hr="http://www.saba.com/hr#">
<operation>contains</operation>
<property>hr:Reports</property>
<value>http://www.saba.com/people/Woodstock</value>
</condition> </select> </rdfquery>
[0981] The following exemplary query ("Query 11") finds all who
have more than two direct reports:
TABLE-US-00111 <?xml version="1.0"?> <!DOCTYPE rdfquery
SYSTEM "rql.dtd"> <rdfquery> <select> <condition
xmlns:hr="http://www.saba.com/hr#">
<operation>count</operation>
<operation>greaterThan</operation>
<property>hr:Reports</property>
<value>2</value> </condition> </select>
</rdfquery>
[0982] The following exemplary query ("Query 12") finds all who
have an advanced competency rating in EJB, with the competency
ratings obtained from evaluations.
TABLE-US-00112 <?xml version="1.0"?> <!DOCTYPE rdfquery
SYSTEM "rql.dtd"> <rdfquery> <select
xmlns:ewp="http://www.saba.com/ewp#"> <condition>
<operation>equals</operation>
<property>ewp:competency</property>
<value>EJB.Advanced</value> <condition>
<operation>contains</operation>
<property>ewp:details</property>
<value>evaluation</value> </condition>
</condition> </select> </rdfquery>
[0983] The following exemplary query ("Query 13") finds everyone
hired in the past month:
TABLE-US-00113 <?xml version="1.0"?> <!DOCTYPE rdfquery
SYSTEM "http://dlipkin/rql.dtd"> <rdfquery> <select
xmlns:hr="http://www.saba.com/hr#"
xmlns:dt="urn:w3-org:xmldatatypes"> <condition>
<operation>greaterThan</operation>
<property>hr:StartDate</property> <value
dt:type="dateTime">sysdate-31</value> </condition>
</select> </rdfquery>
Information Distributor Implementation
[0984] The following is an exemplary implementation embodiment of
Info Distributor in the platform of the invention. The
implementation has two components:
[0985] 1. DatabaseMR--a Java class that implements a Metadata
Repository (MR) on top of a relational database. This class
provides utility methods to be invoked by Import Agents, Match
Agents, and Delivery Agents.
[0986] 2. RQL parser--a Java class that implements the RQL query
language. It parses an RQL document and executes the query using
the DatabaseMR.
[0987] In an embodiment, DatabaseMR implements the MR interface,
that is, it provides the ability to import an RDF document, return
the value of an RDF property, and perform a metadata match.
[0988] DatabaseMR uses a database schema containing the following
tables:
[0989] MR_sources--contains URI references to each imported
document
TABLE-US-00114 Column Datatype Description Id number Primary key
source_URI varchar2(1024) URI of imported document
[0990] MR_triples_base--stores the actual data of all RDF triples
from imported RDF documents.
TABLE-US-00115 Column Datatype Description uri_ref number Foreign
key to MR_sources table rdf_property varchar2(1024) Property values
rdf_resource varchar2(1024) Resource values rdf_object
varchar2(1024) Object values
[0991] In addition, there is a view called MR_triples defined
as
[0992] CREATE VIEW MR_triples AS (SELECT rdf_property,
rdf_resource, rdf_object FROM MR_triples_base)
[0993] This view allows other data sources to also be manipulated
by the MR, as described below.
[0994] As an example, the following RDF document:
TABLE-US-00116 <?xml version="1.0"?> <rdf:RDF
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax- ns#"
xmlns:dc="http://purl.org/dc/elements/1.1/"
xmlns:schedule="http://www.saba.com/RDF/schedule/1.0#">
<rdf:Description resource="http://dlipkin/class1">
<dc:title>HTML Fundamentals</dc:title>
<schedule:startDate>1998-12-07</schedule:startDate>
</rdf:Description> </rdf:RDF>
[0995] appears as the following data:
TABLE-US-00117 rdf_resource rdf_property rdf_object
http://dlipkin/class1 http://purl.org/dc/elements/1.1/title HTML
Fundamentals http://dlipkin/class1 http://www.saba.com/RDF/
1998-12-07 schedule/1.0#startDate
[0996] The methods of DatabaseMR are implemented as follows:
importRDF( ) The importRDF( ) method imports RDF data. It uses
W3C's open-source RDF parser, SiRPAC
(http://www.w3.org/RDF/Implementations/SiRPAC/) to generate triples
from an RDF document.
[0997] This algorithm followed by this method is:
[0998] 1. See if this document has already been imported. If so,
delete all triples resulting from the previous import.
[0999] 2. Insert the key for this document into MR_sources.
[1000] 3. Invoke SiRPAC to parse the document and generate triples,
using Java code similar to the following:
TABLE-US-00118 private void generateTriples(Reader r, String key)
throws ImportException { r = (Reader) new RDFReader(r); InputSource
source = new InputSource(r); source.setSystemId(key);
[1001] RDFConsumer consumer=(RDFConsumer) new
DatabaseMRConsumer(this);
TABLE-US-00119 mSirpac.setRDFSource(source);
mSirpac.setStreamMode(mUSE_STREAMING_PARSER);
mSirpac.register(consumer); mSirpac.fetchRDF( ); }
[1002] where DatabaseMRConsumer is a callback class invoked by
SiRPAC that simply invokes the insertTriple( ) method of
DatabaseMR:
TABLE-US-00120 private class DatabaseMRConsumer implements
RDFConsumer { private DatabaseMR mMR; public
DatabaseMRConsumer(DatabaseMR theMR) { mMR = theMR; } public void
start (DataSource ds) { } public void end (DataSource ds) { }
public void assert (DataSource ds, Resource predicate, Resource
subject, RDFnode object) { mMR.insertTriple(predicate.toString( ),
subject.toString( ), object.toString( )); } };
[1003] 4. Insert each triple into the MR_triples_base table using a
prepared statement of the form:
TABLE-US-00121 INSERT INTO MR_triples_base(id, uri_ref,
rdf_property, rdf_resource, rdf_object) VALUES(MR_sequence.nextval,
?, ?, ?, ?)
[1004] 5. Commit the transaction.
match( )
[1005] The match( ) method takes a MatchDescriptor specifying a
Match Agent and Delivery Agent and performs a match. It uses the
following algorithm:
[1006] 1. Extract the RDF query and target RDF document from the
MatchDescriptor.
[1007] 2. Parse the query using RQLParser.
[1008] 3. Execute the query by invoking the getResources( ) method
on the root Operator returned by RQLParser. Pass in the target RDF
document as an argument, and obtain a result Vector of matching
resource Strings.
[1009] 4. Construct a MatchResultSet of the query results.
[1010] 5. Dispatch the query results to the Delivery Agent.
getProperty( )
[1011] The getProperty( ) method returns the value for a specific
property stored in the MR. It does this by invoking a SQL statement
of the form:
TABLE-US-00122 SELECT rdf_object FROM MR_triples WHERE rdf_resource
= ? AND rdf_property = ?
Database Schema
[1012] The database schema used has two main advantages:
[1013] 1. Simplicity. All RDF data is stored in a single table and
all SQL is written to read and write to this table.
[1014] 2. Support for non-RDF data. It is simple to cast non-RDF
data into this format so that existing or legacy data can be
queried by the DatabaseMR using RQL.
[1015] So, for example, for the following example data stored in an
"invoices" table:
TABLE-US-00123 Id last_updated customer 1 10-JAN-99 Ford 2
25-FEB-99 Cisco
[1016] The view used by the MR can be augmented as followed to
incorporate this data:
TABLE-US-00124 create view invoice_date_triples as select
`last_updated` "rdf_property", (`invoice#` || id) "rdf_resource",
to_char(last_updated, `YYYY-MM-DD`) "rdf_object" from
test_invoices; create view invoice_customer_triples as select
`customer` "rdf_property", (`invoice#` || id) "rdf_resource",
customer "rdf_object" from test_invoices; drop view MR_triples;
create view MR_triples as (select rdf_property, rdf_resource,
rdf_object from invoice_date_triples) union (select rdf_property,
rdf_resource, rdf_object from invoice_customer_triples) union
(select rdf_property, rdf_resource, rdf_object from
MR_triples_base);
[1017] This will result in the following additional triples being
available from the MR:
TABLE-US-00125 rdf_resource rdf_property rdf_object invoice#1
last_updated 10-JAN-99 invoice#1 customer Ford invoice#2
last_updated 25-FEB-99 invoice#2 customer Cisco
[1018] The disadvantage to this schema is that it is not normalized
and stores a tremendous amount of duplicate data. Many values for
rdf_resource and rdf_property will be duplicated, since the same
resource will have a number of properties, and property names will
come from a well-known set.
RQLParser
[1019] RQLParser parses an RQL document and builds an execution
plan for the query. The plan consists of a tree of Java classes
called "Operators," where each Operator is responsible for
returning a Vector of matching resources.
[1020] The Operator interface is defined as follows:
TABLE-US-00126 public interface Operator { /** * An operator knows
how to return a Vector of matching resource values * (typically
URIs). * @param conn JDBC connection to the MR * @param targetRDF
Target RDF file. * @return Vector of matching resources *
@exception SQLException Thrown on a database error */ public Vector
getResources (Connection conn, String targetRDF) throws
SQLException, ParseException; } /* Operator */
[1021] A variety of Operators are provided, each of which is
responsible for handling different RDF constructs or RQL
operations. Some of the available Operators are:
[1022] AndOperator--implements the "and" boolean operator. It
contains an array of child Operators. It calls getResources( ) on
each one, then constructs a result Vector of the resource that are
present in each and every child.
[1023] OrOperator--implements the "or" boolean operator. It
contains an array of child Operators. It calls getResources( ) on
each one, then constructs a result Vector of the resource that are
present in any child.
[1024] SimpleOperator--an abstract class that contains a property
string, a value string, and a child Operator. It is the superclass
for both SingleOperator and ContainerOperator.
[1025] SingleOperator--a SimpleOperator that handles basic
expressions, ie equals or notEquals. It executes a SQL query of the
form:
TABLE-US-00127 SELECT DISTINCT rdf_resource FROM (SELECT * FROM
MR_triples WHERE rdf_property = ?) WHERE rdf_object [operation]
?
[1026] The value for [operation] is provided by the concrete
subclass. Available subclasses include:
[1027] Equals Operator
[1028] NotEqualsOperator
[1029] GreaterThanOperator
[1030] LessThanOperator
[1031] LikeOperator
[1032] The value used to match the rdf_object can either be
provided as hard-coded text in the RQL document, or it can be
defined as a variable containing a propertyName. In this case, a
metadata match is performed, using the target RDF document as the
source for the property value.
[1033] ContainerOperator--a SimpleOperator that operates on an RDF
container (a Bag, Seq, or Alt). It contains a child operator that
it executes to return a set of generated resources representing the
RDF container. It then executes a SQL query of the form:
TABLE-US-00128 SELECT rdf_resource FROM MR_triples WHERE
rdf_property = ? AND rdf_object = ?
[1034] where each rdf_object is set to one of the child
resources.
[1035] Additionally, there is an OperatorRegistry class where each
Operator is registered with the RQL operation it supports.
[1036] RQLParser uses the following algorithm and methods for
generating the execution plan:
[1037] 1. parse( ):
[1038] Parse the RQL document using a standard XML parser to obtain
the resulting DOM tree.
[1039] Navigate to the main condition node and call parseCondition(
) on it.
[1040] 2. parseCondition( ):
[1041] If the condition is a boolean, call parseBoolean( ).
[1042] Otherwise, call parseOperation( ).
[1043] 3. parseBoolean( ):
[1044] Obtaining each child node and recusively calling
parseCondition( ) on each one.
[1045] Create the appropriate Operator for the boolean
(AndOperator, OrOperator, NotOperator) with the children obtained
by calling parseCondition( ).
[1046] 4. parseOperation( ):
[1047] Obtain the operation, property, and value nodes.
[1048] Extract the text values of these nodes, and call
createOperator( ) with these values.
[1049] 5. createOperator( ): [1050] a. Use the OperatorRegistry to
obtain the Java class of the Operator responsible for this
operation. [1051] b. Use Java reflection to create a new instance
of this Operator class, passing in the appropriate parameters.
Agents
[1052] Agents are implemented as clients of the DatabaseMR
class.
[1053] For example, a simple ImportAgent will pass its text RDF
argument to the importRDF( ) method:
TABLE-US-00129 public class SimpleImportAgent implements
ImportAgent { private MR mMR = null; public SimpleImportAgent(MR
theMR) { mMR = theMR; } public void importRDF(String rdf) throws
ImportException { Reader r = (Reader) new StringReader(rdf); /*
this import has a unique key so it can never be overridden by
subsequent imports */ String key = "generated" +
System.currentTimeMillis( ); mMR.importRDF(r, key); } /* importRDF
*/ } /* SimpleImportAgent */
[1054] A simple MatchAgent will take an RQL document and a
DeliveryAgent as parameters, and invoke the match( ) method:
TABLE-US-00130 public class SimpleMatchAgent implements MatchAgent
{ private MR mMR = null; private DeliveryAgent mDA = null; private
MatchDescriptor mMD = null; public SimpleMatchAgent(MR theMR,
String rql, DeliveryAgent theDA) { mMR = theMR; mDA = theDA; mMD =
new MatchDescriptor(rql, "", (MatchHandler) theDA); } public void
match( ) throws MatchException { mMR.match(mMD); } /* match */ } /*
SimpleMatchAgent */
[1055] A simple DeliveryAgent prints the RDF document containing
the matching resources to System.out:
TABLE-US-00131 public class SimpleDeliveryAgent implements
MatchHandler { public void deliver(MatchResultSet mrs) throws
DeliveryException { String xml = mrs.toXML( );
System.out.print(xml); } } /* SimpleDeliveryAgent */
BEST MODE
[1056] As indicated earlier in FIG. 3, the architecture of a
preferred embodiment of the present invention adopts a three-tier
model. Referring now to FIG. 17, the various types of computer
hardware and computer software used in a preferred embodiment at
the present time are depicted in greater detail. In FIG. 17, a tier
1 user workstation 1701 and a tier 1 dedicated user personal
computer (PC) 1703 are connected electronically to a tier 2 web
server 1707 via the Internet 1709. FIG. 17 also shows a tier 1 user
smart phone 1705 directly connected to a tier 2 application server
1711, such as the SABA Business Platform. And the tier 2
applications server 1711 may be connected to a tier 3 database
management system 1713, additional external SABA systems 1715,
external third party systems 1717 and/or third party knowledge
management systems 1719.
[1057] The user workstation 1701 can be a Sun.RTM. Ultra5.TM.
workstation and the user PC 1703 can be any general purpose PC.
Note that the list of tier 1 devices presented in this preferred
embodiment are not conclusive. Other tier 1 user devices could be
WebTV or other Personal Assistant Devices (PDAs). A Sun E250.TM.
dual processor server can be used as a development/test system
running the Sun.RTM. Solaris.RTM. operating environment,
Oracle.RTM. 8I. A single processor Sun E250.TM. server can be used
for the SABA Business Platform, as a Sun E4500.TM. dual processor,
an IBM NetFinity 7000.TM. quad processor with a Microsoft.RTM.
NT.TM. server and a Hitachi Shared Disk array. The workstation 1701
and the PC 1703 can interface to the tier 2 SABA Business Platform
through the Internet 1709 using a standard Internet browser such as
Internet Explorer.TM.. The tier 3 database can be located on an
Oracle 8I.RTM. server, a SQL server, or Informix. The Sun E250.TM.
dual processor server can interface with the external third party
systems 1717 via third party system specific adapter plugs. The Sun
E250.TM. dual processor server also interfaces with external SABA
systems 1715 via SABA exchange. Finally, the Sun E250.TM. dual
processor server can also interface with the tier 3 database
management system 1713 located on the Oracle 8I.RTM. server.
[1058] Referring again to FIG. 17, the tier 2 applications server
1711 is expanded to illustrate the SABA Business Platform
(Platform) of the present invention. In FIG. 17, the Platform
contains an Interface Server 1721, an Information Server 1723, an
Interconnect Server 1725, and a Business Server 1727. In a
preferred embodiment, all of these Servers 1721, 1723, 1725, and
1727 may physically reside on the same hardware platform (such as a
UNIX box or a Microsoft.TM. NT.TM. platform), or each server may
reside on a separate hardware box, or any combination of servers
and hardware boxes. Each of the servers has included a JAVA Virtual
Machine.TM. and the related runtime support.
[1059] In a preferred embodiment, the business server 1727 embodies
the containers which incorporate all of the business logic, common
business objects, SABA core objects, and a database driven
framework for generating notifications and for triggering periodic
events based on context sensitive attachments. The business server
1727 communicates with each of the other servers within the
Platform using the XML protocol (1727, 1729, and 1731). The
Business Server 1727 also communicates with the database management
system 1713. In communicating with the interface server 1721, the
business server 1727 first generates a XML message 1729 and
transmits it to the interface server 1721. The interface server
1721 then performs style sheet transformations on the XML using XSL
or XSLT to translate the XML message into the particular
Applications Programming Interface (API) language required to
communicate with a particular user. For example, if a particular
user is accessing the Platform via a workstation 1701 or a PC 1703,
the Interface Server 1721 can convert the XML 1729 into HTML 1735
and communicate with the user through a web server 1707 via the
Internet 1709. The Interface Server 1721 can also convert the XML
into other protocols such as WAP/WML 1737 to communicate with
Personal Data Assistants (PDAs) such as cell phones 1705, Palm
Pilots.TM., or other such wireless devices. Since the interface
that is generated between the Platform and the various user
interfaces is dictated by the set of style sheets generated in the
Interface Server 1721, the same core business logic can be
leveraged to communicate across a number of different user
interfaces.
[1060] The Interconnect server 1725 uses XML to communicate with
both the Information server 1723 and the Business server 1727 and
is responsible for all connectivity external to the Platform.
Externally, the Interface Server 1721 may communicate with third
party systems such as SAP.TM. accounting or personnel packages,
Oracle.TM. financial or human resources, other SABA Platforms 1715,
and generally any external system to which a portion of the
Interconnect facilities may be connected. The Interconnect server
1725 comprises SABA interconnect 1739 which is essentially a
backplane into which cards or interconnect services can be plugged.
Examples of these cards or interconnect services can be an event
monitor 1741, exchange registry, node manager 1747, connectors,
accessor 1743, or subscribers 1745. Each of these cards or
interconnect services leverage the services provided by the SABA
interconnect backplane 1739 for communicating between the cards
themselves and for providing more sophisticated services to third
party systems 1717.
[1061] A preferred embodiment of the Platform may interconnect with
a third party system 1717 having, for example, an Oracle human
resources (HR) database 1749 and an Oracle financial database 1751.
The third party system 1717 has a third party interconnect
backplane 1753 with similar cards or interconnect services. The
third party interconnect backplane 1753 connects to the third party
databases 1749 and 1751 via system specific adapters 1755. These
system specific adapters 1755 differentiate between different types
of databases such Oracle, SAP, or PeopleSoft and feed into the
standardized Platform framework so information can be exchanged. An
example of information that can be exchanged includes HR
information. When a new employee is added to or terminated from the
third party HR system database 1749, the monitor 1757 located on
the third party interconnect backplane 1753 notifies the subscriber
1745 located on the SABA interconnect backplane 1739 via XML 1759.
The accessor 1743 on the SABA interconnect backplane 1739 can then
access the new employee data via XML. The Interconnect server 1725
then performs style sheet transformations to convert the XML into
the Platform's native format and transmits that data to the
Business server 1727 which then updates the database management
system 1713. This data connection can be set to be automatic or
with modifications.
[1062] In a preferred embodiment, the Interconnect server 1725 also
embodies a workflow and notification scheme. For example, if a
group of students signed up for a class through the Platform and
later the class time changes, the Platform can detect this change
and initiate a workflow to obtain all the names of the students
from the database management system 1713 and send an email to them
notifying them of the change. Thus, the interconnect server 1725
can provide real-time, in-order, reliable updating of data,
financial transactions, or management of human capital between the
Platform and third party systems 1717.
[1063] The Interconnect server 1725 can also be used to synchronize
the Platform with other external SABA systems 1715. For example,
the Platform can publish a catalog and based on permissions that
are set, the catalog can be subscribed to by some other external
SABA systems 1715. Whenever changes are made to the catalog, the
external SABA systems 1715 can monitor that change and obtain an
update immediately. The Interconnect server 1725 can also connect
to SABA private learning networks which are connected to SABA
public learning networks via SABA Exchange. For example, a third
party such as Ford Automotive may have a SABA system allowing them
to exchange catalog or class course information via the
interconnect server 1725.
[1064] The Information Server 1723, communicates with the
Interconnect server 1725 and the Business Server 1727 via XML. The
Information Server 1723 also communicates directly with the
database management system 1713 for query and storage of metadata
1733. The Information server 1723 focuses on queries and
distributed queries and keeping track of information about other
pieces within the Platform. The Information Server 1723 can also
leverage the Interconnect server 1725 to connect to a third party
knowledge management system 1719 that generates information via the
SABA Interconnect backplane 1739. For example, a third party may
have a third party Interconnect backplane 1761 connected to a
Knowledge Management System 1719 which monitors and exchanges data
with the Platform via XML. The Information Server 1723 contains
Import, Match and Delivery agents to resolve and generate
information requests; Match templates to match metadata; and
template-based services that respond to information requests and
are capable of rendering their results in XML; and
Finders--metadata driven, template-based query builders that
generate optimized SQL queries in the native SQL language of the
particular database involved.
[1065] Having described the invention in terms of a preferred
embodiment, it will be recognized by those skilled in the art that
various types of general purpose computer hardware may be
substituted for the configuration described above to achieve an
equivalent result. Similarly, it will be appreciated that
arithmetic logic circuits are configured to perform each required
means in the claims for performing the various features of the
rules engine and flow management. It will be apparent to those
skilled in the art that modifications and variations of the
preferred embodiment are possible, such as different computer
systems may be used, different communications media such as
wireless communications, as well as different types of software may
be used to perform equivalent functions, all of which fall within
the true spirit and scope of the invention as measured by the
following claim.
* * * * *
References