Professional Ajax, 2nd Edition

6.3. XSL Transformation Support in Browsers

eXtensible Stylesheet Language (XSL) is a family of languages that are designed to transform XML data. XSL refers to three main languages: XSL Transformations (XSLT), which is a language that transforms XML documents into other XML documents; XPath, which was discussed in the previous section; and XSL Formatting Objects (XSL-FO), which describes how the transformed data should be rendered when presented. Since no browser currently supports XSL-FO, all transformations must be accomplished through the use of XSLT.

6.3.1. Introduction to XSLT

XSLT is an XML-based language designed to transform an XML document into another data form. This definition may make XSLT to be a not-so-useful technology, but the truth is far from the matter. The most popular use of XSLT is to transform XML documents into HTML documents, which is precisely what this introduction covers.

XSLT documents are nothing more than specialized XML documents, so they must conform to the same rules as all XML documents: they must contain an XML declaration, they must have a single root element, and they must be well formed.

As an example, consider books.xml. The information contained in this file can be transformed into HTML using XSLT, without the need to build the DOM structure manually. For starters, you need an XSLT document, books.xsl, which begins with an XML declaration and a root element:

<?xml version="1.0" encoding="UTF-8" ?> <xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"> ...