Web based School

Stylesheet Examples

Example 1. A Stylesheet

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
               version="1.0">
    ...
</xsl:stylesheet>

Example 2. A Transformation Sheet

<eg:transform xmlns:eg="http://www.w3.org/1999/XSL/Transform"
               version="1.0">
    ...
</eg:transform>

Example 3. Document as Stylesheet

<html xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<head>
<title>Silly Example</title>
</head>
<body>
<h1>Silly Example</h1>
<p>You'd probably use extension elements, or somthing
more interesting in real life: 3+4 is <xsl:value-of select="3+4"/>.
</p>
</body>
</html>

A Complete Example

This is a simple stylesheet that transforms source <para> and <emphasis> elements into HTML:

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

<xsl:template match="para">
  <p><xsl:apply-templates/></p>
</xsl:template>

<xsl:template match="emphasis">
  <i><xsl:apply-templates/></i>
</xsl:template>

</xsl:stylesheet>

With this stylesheet, the following XML document:

<?xml version='1.0'?>
<para>This is a <emphasis>test</emphasis>.</para>

Would be transformed into:

<?xml version="1.0" encoding="utf-8"?>
<p>This is a <i>test</i>.</p>

Note that this has been serialized as XML.

Understanding A Template

Most templates have the following form:

<xsl:template match="emphasis">
  <i><xsl:apply-templates/></i>
</xsl:template>

The whole <xsl:template> element is a template
The match pattern determines where this template applies
Literal result element(s) come from non-XSL namespace(s)
XSLT elements come from the XSL namespace

Match Patterns (Locating Elements)

One critical capability of a stylesheet language is to locate source elements to be styled. CSS, for example, does this with "selectors." FOSIs do it with "e-i-c's", elements in context. XSLT does it with "match patterns" defined by the XML Path Language (XPath) (http://www.w3.org/TR/xpath).

XPath has an extensible string-based syntax
It describes "location paths" between parts of a document or documents
One inspiration for XPath was the common "path/file" file system syntax

Two things to remember about XPath expressions:

Pattern matching occurs in a context; XPath expressions and XSLT elements can change the current context and consequently the nodes which match
XPath is inclusive or greedy, it addresses all matching elements. You must use predicates to refine the set of nodes selected.

Pattern Examples

para: Matches all <para> children in the current context
para/emphasis: Matches all <emphasis> elements that have a parent of <para>
/: Matches the root of the document
para//emphasis: Matches all <emphasis> elements that have an ancestor of <para>
section/para[1]: Matches the first <para> child of all the <section> children in the current context
//title: Matches all <title> elements anywhere in the document
.//title: Matches all <title> elements that are descendants of the current context

More Complex Patterns

section/*/note: Matches <note> elements that have <section> grandparents.
stockquote[@symbol]: Matches <stockquote> elements that have a "symbol" attribute
stockquote[@symbol="XXXX"]: Matches <stockquote> elements that have a "symbol" attribute with the value "XXXX"
emphasis|strong: Matches <emphasis> or <strong> elements