Gaurav,
Have you considered using Java applets and XSLTC rather than
Javascript? You wouldn't have to write an XPath processor.
We have some documenation on how to use XSLTC for applets.
I've attached a README so you can get an idea if it makes
any sense for you. Or you can look at the files in the
Xalanj2 cvs workspace at
.../xml-xalan/java/samples/CompiledApplet/*
Tom
Gaurav Pal wrote:
>
> Hi,
>
> I'm currently working on a project which requires me to develop an XForms
> emulator on the clients browser, so everything is required to be implemented
> in JavaScript.
>
> For this I need an XML parser with a XPath processor, all implemented in
> JavaScript so it can run on the client browser. I'm using the open source
> JavaScript implementation XML parser available at
> http://www.cjandia.com/2001/espx-tinyxsl/. I need to write a XPath processor
> in JavaScript to complement this (course my work will also be available as
> an open source project at the same location).
>
> I'm hoping u can make the Xalan XPath processor design available to me so I
> get some place to start. I'm currently looking into the source code. But
> it'll be a lot faster if I had some design documents.
>
> Hoping you can help.
>
> Thanks.
>
> -Gaurav
--
Tom Amiro -- SQA Engineer
Sun XML Technology Development
voice: 781-442-0589 Fax: 781-442-1437
eMail: [email protected]
======================================================================
The XSLT Compiler (XSLTC) is a Java-based tool for compiling XSL
stylesheets into extremely lightweight and portable Java byte code.
The XSLTC Java Runtime environment can then process XML files against
these compiled stylesheets (Translets) to generate any manner of
output per the stylesheet instructions.
This Applet Demo shows you how translets can be run in a client
browser as Java applets to perform XSLT transformations on XML
source documents residing on a Web server. Because of XSLTC's small
footprint, it is possible to download the compiled stylesheets
(translets) and the runtime classes in the applet. Whereas, this
would not be easy with a fullsize Java-based XSLT processor.
There are two important advatages of this approach:
1) It offloads XSLT processing from the server
2) It enables browsers, such as Netscape 4.x, that do not have native
XSLT support to perform XSLT transformations today!
-----------------------------------------------------------------------
DEMO CONTENTS
-----------------------------------------------------------------------
The applet demo is very generic. It will let you run any pre-compiled
translet through an applet, and it lets you use that on any XML file
you can refer to using an URL. The contents of this demo are:
TransformApplet.java - The applet that wraps the XSLTC runtime
classes and your translet(s).
index.html - Your main HTML document (displays two frames)
menu.html - The HTML document for your dialog frame. This is the
document that invokes the TransformApplet
-----------------------------------------------------------------------
HOW TO SET UP THE DEMO ON YOUR SITE
-----------------------------------------------------------------------
1. Install and configure Xalan with XSLTC
2. Compile the stylesheets you want to export. This will result in one
or more small Java classes (translets).
3. Create a JAR file with your the applet class (compile it first, of
cource), your translet classes and these classes from the xalan/xsltc
package:
org/apache/xalan/xsltc/*.class
org/apache/xalan/xsltc/dom/*.class
org/apache/xalan/xsltc/runtime/*.class
org/apache/xalan/xsltc/util/*.class
Be sure to make the JAR file world readable!
4. Make your XML source documents readable through a URL (either place
them behind a web server or make them readable for your browser as
a file).
5. Open the supplied index.html and try out the demo!
----------------------------------------------------------------------
KNOW PROBLEMS
----------------------------------------------------------------------
The following problems are specific to the Netscape 4.x browser.
Class Already Loaded - If you start up the Netscape client browser on
a Unix system where you have been running XSLTC, and consequently
have a CLASSPATH that includes xml.jar, and xlstcrt.jar, the applet
demo fails. You'll see a message saying a class has already been
loaded in the Javascript console. To bring up the Javascript console,
you type
javascript:
in the location/URL field of the browser. To work around this problem,
unset your CLASSPATH before starting Netscape from a terminal window.
This still may not resolve the problem if Netscape is started from
a wrapper that sets your environment from your startup file (e.g.,
your .cshrc file for the C-shell).
Parser Exception - This problem only applies to Netscape on the
Windows platform with XML documents that have an external DTD.
If you see the following message:
org.xml.sax.SAXParseException:
External parameter entity "%(DOCTYPE);"
has characters after markup.
try removing the reference to an external DTD in your XML source.
----------------------------------------------------------------------
END OF README
