Microsoft XML parser version 4 released (2/2) - exploring XML | WebReference

Microsoft XML parser version 4 released (2/2) - exploring XML

Microsoft XML parser version 4 released

Confusion and variety increased

Interesting is the declaration of XDR as a standard by Microsoft, where everybody else seems to look to XML Schema for the same purpose. While all the other improvements do indeed point in the direction of W3C specifications, the premature shipping of the old XSL technology and its removal in the current incarnation creates a new challenge to the Internet Explorer developer community:

How do you actually write an XSL style sheet that works in IE 5.0 with MSXSL 2 and IE 5.5 or 6.0 with MSXSL 4? The answer is simple: You'd have to write two, one the old XSL way and one the new, standard XSLT method. And then, finding out which version is installed at a particular client and conditionally including the right style sheet I have not yet managed to achieve with script hackery. If you faired better let me know.

Seems that Microsoft has also given up on any sort of backwards compatibility. Citing MSDN:
"True side-by-side functionality, which ensures that MSXML 4.0 can work without any collision with previous or future versions of MSXML. As a result, replace mode is removed completely. XmlInst.exe will not work with this release. Version-independent ProgIDs, such as DOMDocument, are also removed. You should use DOMDocument.4.0 to get MSXML 4.0 functionality."
This means you finally have to decide for yourself which version of a certain implementation you want to use, and be aware of its specific functionality and issues. Or support all of them, to be on the safe side...

Installation complicated

If you installed a preview version of MSXML 4.0, uninstall it first. Manually remove the msxml4*.dll files if necessary and then issue:
regsvr32 /u msxml4.dll
regsvr32 msxml3.dll

Citing MSDN again:
"This will restore version-independent ProgIDs, which have been removed from MSXML 4.0, to point back to MSXML 3.0. It is important that you do this before installing this release."

Conclusion

While this new release of XML functionality for Microsoft platforms advances the convergence of W3C standards, it complicates XML processing on the client side further by inflicting yet another different set of functionality, behaviors and issues in Windows clients. On the server side it is highly recommended to upgrade your existing code to DOMDocument.4.0 in order to take full advantage of the improvements made.

Produced by Michael Claßen

URL: http://www.webreference.com/xml/column42/2.html
Created: Oct 29, 2001
Revised: Oct 29, 2001