U.S. patent application number 12/173416 was filed with the patent office on 2008-11-06 for lazy document and data validation.
This patent application is currently assigned to International Business Machines Corporation. Invention is credited to Ashish Kundu, Amit Anil Nanavati.
Application Number | 20080275947 12/173416 |
Document ID | / |
Family ID | 34677122 |
Filed Date | 2008-11-06 |
United States Patent
Application |
20080275947 |
Kind Code |
A1 |
Kundu; Ashish ; et
al. |
November 6, 2008 |
Lazy Document and Data Validation
Abstract
Client-side scripts are repackaged on the server side to be sent
to the client with the corresponding data element. They are
packaged to appear no earlier than the program location of a first
corresponding data element. The document is rendered as it arrives
at the client. In parallel, execution of the scripts to validate
corresponding data elements occurs no sooner than rendering of the
data elements. Validation of the document is delayed until the
document download (and validation) has been performed.
Inventors: |
Kundu; Ashish; (Orissa,
IN) ; Nanavati; Amit Anil; (New Delhi, IN) |
Correspondence
Address: |
FREDERICK W. GIBB, III;Gibb & Rahman, LLC
2568-A RIVA ROAD, SUITE 304
ANNAPOLIS
MD
21401
US
|
Assignee: |
International Business Machines
Corporation
Armonk
NY
|
Family ID: |
34677122 |
Appl. No.: |
12/173416 |
Filed: |
July 15, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10727885 |
Dec 4, 2003 |
|
|
|
12173416 |
|
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Current U.S.
Class: |
709/203 |
Current CPC
Class: |
H04L 67/04 20130101;
H04L 67/2819 20130101; H04L 67/289 20130101; H04L 67/06
20130101 |
Class at
Publication: |
709/203 |
International
Class: |
G06F 15/16 20060101
G06F015/16 |
Claims
1. A method for downloading a document from a server computer to a
client computer, said method comprising the steps of: repackaging
scripts in a document program at the server such that scripts are
in a program location no earlier than the program location of a
first corresponding data element; downloading the repackaged
document program to said client; rendering said repackaged document
at said client as it arrives until complete; and in parallel with
said rendering step, scheduling execution of said scripts by said
client to validate corresponding data elements no sooner than said
step of rendering.
2. The method of claim 1, further comprising validating the
rendered document once completely rendered.
3. The method of claim 1, wherein said repackaging step packages
all scripts required by the first data element whose validation
requires those scripts.
4. The method of claim 1, wherein said scheduling step executes a
script as it is downloaded from said server.
5. The method of claim 1, wherein said scheduling step executes a
script once all data elements relying on said script have been
downloaded from said server.
6. A computer system for downloading a document comprising: a
server computer operable to repackage a document program at the
server such that scripts are in a program location no earlier than
a first corresponding data element; and a client computer operable
to download the repackaged document program, render said document
as it arrives until complete, and, in parallel with the rendering,
schedule execution of said scripts to validate corresponding data
elements no sooner than rendering.
7. The computer system of claim 6, wherein said client computer
validates said rendered document once completely rendered.
8. The computer system of claim 6, wherein said server computer
repackages all scripts required by the first data element whose
validation requires those scripts.
9. The computer system of claim 6, wherein said client computer
schedules execution of a script as it is downloaded from said
server computer.
10. The computer system of claim 6, wherein said client computer
schedules execution of a script once all data elements relying on
said script have been downloaded from said server computer.
11. A client computer for downloading from a server computer a
repackaged document having scripts that are in a program location
no earlier than the location of a first corresponding data element,
said client computer being operable to render said document as it
arrives until complete, and, in parallel with the rendering,
schedule execution of said scripts to validate corresponding data
elements no earlier than rendering.
12. The client computer of claim 11, wherein execution of a script
is scheduled as it is downloaded from said server computer.
13. The client computer of claim 11, wherein execution of a script
is scheduled once all data elements relying on said script have
been downloaded from said server computer.
14. A server computer operable to repackage a document program such
that scripts are in a program location no earlier than a location
of a first corresponding data element.
15. The server computer of claim 14, wherein said repackaging is of
all scripts required by the first data element whose validation
requires those scripts.
16. A computer program product comprising a computer program
recorded on a storage medium, said program comprising: computer
program element means for repackaging a document program at a
server computer such that scripts are in a program location no
earlier than a location of a first corresponding data element;
computer program element means for downloading the repackaged
document program to a client computer; computer program element
means for rendering said document at said client computer as it
arrives until complete; and computer program element means for, in
parallel with execution of said program element for said rendering,
scheduling execution of said scripts by said client computer to
validate corresponding data elements no sooner than rendering.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation of U.S. application Ser.
No. 10/727,885 filed Dec. 4, 2003, the complete disclosure of
which, in its entirety, is herein incorporated by reference.
FIELD OF THE INVENTION
[0002] This invention relates to documents downloaded in
client-server computing systems. It relates particularly to
validation and rendering of such documents.
BACKGROUND
[0003] FIG. 1A shows a client-server system 10, where a client
machine or node 12 has a direct connection via a network link 14 to
a server machine 16. FIG. 1B shows an alternate arrangement of a
client-server system 10' where a proxy machine 18 forms the
connection with the network 14, and offers processing support for
the client machine 12, passing data across a local link 20. A proxy
is typically used where sophisticated scheduling algorithms are
used. The client machine 12 will be running a user agent software
application, such as a browser.
[0004] A known manner of downloading documents will be described
with reference to FIG. 2. A client begins a downloaded process
(step 30). Any client-side scripts within the document are
downloaded first (step 32). Such scripts can include Javascripts as
part of the HEAD node in a HTML document. This continues until the
script download is complete (step 34). The document itself is then
downloaded to completion (step 36). Validation of the document is
then performed (step 38); for example DOCTYPE and DTD-based
validation in XML. The document is then rendered to the client
(step 40).
[0005] This known arrangement is less than satisfactory for users,
however, in that there is excessive waiting time, leading to
frustration, particularly for thin-clients (eg. mobile devices such
as cellular phones and PDAs). There also is poor resource
utilization, in that dead scripts can be downloaded and need to be
stored in memory.
SUMMARY
[0006] Client-side scripts are repackaged on the server side to be
sent to the client with the corresponding data element. They are
packaged to appear no earlier than the program location of a first
corresponding data element. The document is rendered as it arrives
at the client. In parallel, execution of the scripts to validate
corresponding data elements occurs no sooner than rendering of the
data elements. Validation of the document is delayed until the
document download (and validation) has been performed.
DESCRIPTION OF DRAWINGS
[0007] FIGS. 1A and 1B are schematic block diagrams of
client-server computer systems.
[0008] FIG. 2 is a block flow diagram of a known document
downloading process.
[0009] FIG. 3 is a block diagram of a process embodying the
invention.
[0010] FIG. 4 is a block diagram of a computing platform for a
client or server machine upon which the invention can be
practised.
DETAILED DESCRIPTION
[0011] An embodiment of the invention will now be described with
reference to FIG. 3. It will be understood that the process
described can reside on either form of computer platform 10, 10'
shown in FIGS. 1A and 1B. The client machine 12 can take many forms
such as personal computers, mobile phones, PDAs, workstations, and
so on. The communication protocols that can be supported include
HTTP, UDP, HTML, XML, WAP, and Bluetooth.
[0012] In response to a client download request, a server
repackages any client-side data validation scripts (step 50), for
example, to temporarily link a script for validating an element
with the element. The client begins downloading the document (step
52). The document is rendered as it arrives at the client (step
54), and the user scripts are scheduled to run contemporaneously
with the corresponding element as it is rendered to validate the
data (step 56). Client resource restrictions may dictate that a
script cannot be held for the lifetime of the application. A script
may therefore be scheduled to be downloaded multiple times,
particularly if a script is needed for cross-element validation.
Only after document download completes (step 58) is validation of
the document (eg. the Document Object Model) performed (step 60). A
user input data validation (step 62) is also performed were such
data exists. This data can include date and numeral inputs. The
process ends (step 64) after the document validation and user input
data validation conclude.
[0013] Repackaging
[0014] A number of variables can apply in implementing repackaging
algorithms. These include:
[0015] client characteristics
[0016] data elements that must be validated
[0017] data elements that can be validated but could be skipped
[0018] data elements whose validation process depends on the
validation of other elements (ie. cross-element validation).
[0019] An algorithm to achieve repackaging is:
[0020] Identify the scripts and elements that necessarily must be
validated.
[0021] Separate necessary scripts from remaining (dead)
scripts.
[0022] Identify the relative orders in which scripts will be
required for validation at the client side.
[0023] Place scripts in document according to relative order.
[0024] Identify the scripts for reach element validation.
[0025] Embed scripts in element tree unless already existing (i.e.
relating to a previous element).
[0026] This algorithm is an expression of a "Greedy" repackaging.
That is, package all scripts required by the first element whose
validation requires them.
[0027] Consider the following HTML document:
TABLE-US-00001 <HTML> <HEAD>
<TITLE>MyFirstPage</TITLE> <Script A> <Script
B> <Script C> <Script D> <Script E> <Script
F> </HEAD> <BODY> <element 1 ; requires E,B>
<element 2 ; requires B> <element 3 ; requires D, B>
<element 4 ; requires A, D, <element 5 ; requires A>
</BODY> </HTML>
[0028] A repackaged form of the document--adopting the Greedy
algorithm is:
TABLE-US-00002 <HTML> <HEAD>
<TITLE>MyFirstPage</TITL </HEAD> <BODY>
<element 1 ; script E,B> <element 2 ; > <element 3 ;
script D> <element 4 ; script A, C> <element 5 ; >
</BODY> </HTML>
[0029] In other words, the repackaged scripts occur no earlier than
the program location of a first corresponding data element.
[0030] Scheduling
[0031] As already mentioned, a script is scheduled for data
validation at the client. Scheduling algorithms can implement the
following approaches: [0032] 1. "Greedy": Download each script
repackaged and validate as soon as possible (on a per element
basis). [0033] 2. "Delayall": Validate all the elements that need a
script at a time. [0034] 3. "Cyclic": Validate the n.sup.th element
value when the n+1.sup.th element is being rendered. The last
element is validated after it is rendered.
[0035] All of these approaches are characterized as being no sooner
than the occurrence of rendering.
[0036] Rendering
[0037] The user agent (e.g. browser) must be configured to display
any part of the downloaded document as soon as it is complete
enough to be displayed. The browser also is configured to allow the
input of user data as soon as a part of the document is
displayed.
[0038] Document Validation
[0039] Document validation is performed in any convenient
manner.
[0040] Computer Hardware and Software
[0041] FIG. 4 is a schematic representation of a computer system
100 that is provided for executing computer software programmed to
perform the techniques described herein. The computer system 100 is
suited to fulfil the role of the client or server as described
herein above. This computer software executes on the computer
system 100 under a suitable operating system installed on the
computer system 100. When operating as the server, the computer
system 100 performs the repackaging scripts process (step 50 of
FIG. 3). When operating as a client, the computer system 100
performs the process functions of steps 52-64 of FIG. 3.
[0042] The computer software is based upon computer program
comprising a set of programmed instructions that are able to be
interpreted by the computer system 100 for instructing the computer
system 100 to perform predetermined functions specified by those
instructions. The computer program can be an expression recorded in
any suitable programming language comprising a set of instructions
intended to cause a suitable computer system to perform particular
functions, either directly or after conversion to another
programming language.
[0043] The computer software is programmed using statements in an
appropriate computer programming language. The computer program is
processed, using a compiler, into computer software that has a
binary format suitable for execution by the operating system. The
computer software is programmed in a manner that involves various
software components, or code means, that perform particular steps
in accordance with the techniques described herein.
[0044] The components of the computer system 100 include: a
computer 120, input devices 110, 115 and video display 190. The
computer 120 includes: processor 140, memory module 150,
input/output (I/O) interfaces 160, 165, video interface 145, and
storage device 155. The computer system 100 can be connected to one
or more other similar computers, using a input/output (I/O)
interface 165, via a communication channel 185 to a network 180,
represented as the Internet.
[0045] The processor 140 is a central processing unit (CPU) that
executes the operating system and the computer software executing
under the operating system. The memory module 150 includes random
access memory (RAM) and read-only memory (ROM), and is used under
direction of the processor 140.
[0046] The video interface 145 is connected to video display 190
and provides video signals for display on the video display 190.
User input to operate the computer 120 is provided from input
devices 110, 115 consisting of keyboard 110 and mouse 115. The
storage device 155 can include a disk drive or any other suitable
non-volatile storage medium.
[0047] Each of the components of the computer 120 is connected to a
bus 130 that includes data, address, and control buses, to allow
these components to communicate with each other via the bus
130.
[0048] The computer software can be provided as a computer program
product recorded on a portable storage medium. In this case, the
computer software is accessed by the computer system 100 from the
storage device 155. Alternatively, the computer software can be
accessed directly from the network 180 by the computer 120. In
either case, a user can interact with the computer system 100 using
the keyboard 110 and mouse 115 to operate the computer software
executing on the computer 120.
[0049] The computer system 100 is described only as an example for
illustrative purposes. Other configurations or types of computer
systems can be equally well used to implement the described
techniques.
CONCLUSION
[0050] Various alterations and modifications can be made to the
techniques and arrangements described herein, as would be apparent
to one skilled in the relevant art.
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