An Introduction to XSLT and XPath

Microsoft XML Parser technology

For this article, I will make use of the Microsoft XML Parser 3.0 (MSXML3) July Preview release. Microsoft has committed to supporting the W3C's XML Recommendation version 1.0 and it is releasing a new preview release of its XML parser every alternate month. For the latest MXSML parser, point your web browser to http://msdn.microsoft.com/xml/default.html.

If you are currently using Microsoft Internet Explorer 5.0, you would have version 2.0 installed in your system. It is important that you download the latest version of MSXML since the older version supports an older version of XSL. The latest MSXML release supports the W3C's XSLT specification.

XSLT, XPath and MSXML3

XSLT is an XML-based language that allows you to transform an XML document to another XML document of a different structure. You can think of XSLT as simply a language that allows you to specify commands (in the form of XSLT elements) to transform an XML document from one form to another.

What about XPath? Since an XML document primarily contains elements and texts, there must be a way for XSLT to locate specific elements. And so the task of XPath is to help XSLT locate specific elements so that they can be processed.

To perform the transformation using XSLT and XPath, you need an XSLT processor. There are quite a number of excellent XSLT processors available on the Internet - XT, Saxon, to name a few. For this article, we will make use of the MXSML3. MSXML3 is more than just an XML parser; it is also an XSLT processor.

Enough theory! I am a strong believer of learning by examples, so let's get started!

Next: A Real-World Example