Using XPath in XSLT Templates

XML Tutorials - Herong's Tutorial Notes

Dr. Herong Yang, Version 4.00

∟Using XPath in XSLT Templates

This section describes how XPath can be used in XSLT templates. An XPath expression can be used in XSLT template to match or select parts of the source XML document, or to product a string output.

XPath expressions can be used in XSLT templates to produce a set of nodes of the source XML document can be matched or selected. For example:

<xsl:template match="LocationPathExpression">
<xsl:apply-templates select="LocationPathExpression"/>
<xsl:for-each select="LocationPathExpression"/>

XPath expressions can also be used in XSLT "value-of" elements to product a string output. For example:

<xsl:value-of select="StringExpression"/>

Note that in this case, the resulting value of data types, including node set, will be converted to a string.

Let's review my sample XML file, dictionary_xsl.xml:

<?xml version="1.0"?>
<?xml-stylesheet type="text/xsl" href="dictionary.xsl"?>
<dictionary>
<!-- dictionary_xsl.xml
   Copyright (c) 2002 by Dr. Herong Yang. http://www.herongyang.com/
-->
 <word acronym="true">
  <name>XML</name>
  <definition referenece="Herong's Notes">eXtensible Markup 
Language.</definition>
  <update date="2002-12-23"/>
 </word>
 <word symbol="true">
  <name><</name>
  <definition>Mathematical symbol representing the "less than" logical 
operation, like: 1<2.</definition>
  <definition>Reserved symbol in XML representing the beginning of 
tags, like: <![CDATA[<p>Hello world!</p>]]>
  </definition>
 </word>
 <word symbol="false" acronym="false">
  <name>extensible</name>
  <definition>Capable of being extended.</definition>
 </word>
</dictionary>

And apply the following XSL file:

<?xml version="1.0"?>
<xsl:stylesheet version="1.0"
   xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<!-- dictionary.xsl, version 3.0
   Copyright (c) 2002 by Dr. Herong Yang. http://www.herongyang.com/
-->
 <xsl:template match="/child::*">
  <pre>
d_<xsl:value-of select="name(self::node())"/>
  <xsl:for-each select="child::word">
w__<xsl:value-of select="name(self::node())"/>
   <xsl:apply-templates select="self::node()"/>
  </xsl:for-each>
  </pre>
 </xsl:template>
 <xsl:template match="child::word">
  <xsl:for-each select="attribute::*">
a___<xsl:value-of select="name(.)"/>=<xsl:value-of select="."/>
  </xsl:for-each>
  <xsl:for-each select="child::*">
e___<xsl:value-of select="name(self::node())"/>
   <xsl:apply-templates select="self::node()"/>
  </xsl:for-each>
 </xsl:template>
 <xsl:template match="child::name | child::definition | child::update">
  <xsl:for-each select="attribute::*">
a____<xsl:value-of select="name(.)"/>=<xsl:value-of select="."/>
  </xsl:for-each>
  <xsl:for-each select="child::text()">
t____<xsl:value-of select="self::node()"/>
  </xsl:for-each>
 </xsl:template>
</xsl:stylesheet>

I got the following output:

d_dictionary
w__word
a___acronym=true
e___name
t____XML
e___definition
a____referenece=Herong's Notes
t____eXtensible Markup 
Language.
e___update
a____date=2002-12-23
w__word
a___symbol=true
e___name
t____<
e___definition
t____Mathematical symbol representing the "less than" logical 
operation, like: 1<2.
e___definition
t____Reserved symbol in XML representing the beginning of 
tags, like: 
t____<p>Hello world!</p>
w__word
a___symbol=false
a___acronym=false
e___name
t____extensible
e___definition
t____Capable of being extended.

Table of Contents

About This Book

Introduction of XML (eXtensible Markup Language)

XML File Syntax

XML File Browsers

DOM (Document Object Model) Programming Interface

SAX (Simple API for XML) Programming Interface

DTD (Document Type Definition) Introduction

Syntaxes of DTD Statements

Validating an XML Document against the Specified DTD Document Type

XSD (XML Schema Definition) Introduction

Syntaxes of XSD Statements