XSLT node transformation in a predefined order

问题:

How do I make transformation follow xml node order?

The xml file is something like this

<root>  
    <paragraph>First paragraph</paragraph>
    <paragraph>Second paragraph</paragraph>
    <unordered_list>
       <list_name>Unordered list name</list_name>
       <list_element>First element</list_element>
       <list_element>Second element</list_element>    
    </unordered_list>
    <paragraph>Third paragraph</paragraph>
</root>

I would like to transform it to HTML

...
<p>First paragraph</p>
<p>Second Paragraph</p>
<h3>Unordered list name</h3>
<ul>
    <li>First element</li>
    <li>Second element</li>
</ul>
<p>Third paragraph</p>
...

When I use xsl:for-each It outputs all paragraphs first and then the list, or the other way round. I want to keep the order of the XML file. I am aware this might be very basic but I seem to be getting nowhere using xsl:choose and xsl:if. So please help me someone.

回答1:

Here is a sample xslt stylesheet that does exactly what you are looking for:

<?xml version="1.0"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
    <xsl:output method="xml" encoding="UTF-8" indent="yes"/>
    <xsl:strip-space elements="*"/>

    <!-- iterate through all the child nodes, 
    and apply the proper template to them -->
    <xsl:template match="/">
        <!-- added an extra div tag, to create a correct xml
        that contains only one root tag -->
        <div>
            <xsl:apply-templates />
        </div>
    </xsl:template>

    <!-- create the **p** tags -->
    <xsl:template match="paragraph">
        <p>
            <xsl:value-of select="text()" />
        </p>
    </xsl:template>

    <!-- create the **ul** tags -->
    <xsl:template match="unordered_list">
        <h3>
            <xsl:value-of select="list_name" />
        </h3>
        <ul>
            <xsl:apply-templates select="list_element" />
        </ul>
    </xsl:template>

    <!-- create the **li** tags -->
    <xsl:template match="list_element">
        <li>
            <xsl:value-of select="text()" />
        </li>
    </xsl:template>
</xsl:stylesheet>

The output of this transformation will be:

<?xml version="1.0" encoding="UTF-8"?>
<div>
    <p>First paragraph</p>
    <p>Second paragraph</p>
    <h3>Unordered list name</h3>
    <ul>
        <li>First element</li>
        <li>Second element</li>
    </ul>
    <p>Third paragraph</p>
</div>

回答2:

A shorter and more consize transformation:

<xsl:stylesheet version="1.0"
 xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
 <xsl:output omit-xml-declaration="yes" indent="yes"/>
 <xsl:strip-space elements="*"/>

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

 <xsl:template match="unordered_list/list_name">
  <h3><xsl:apply-templates/></h3>
 </xsl:template>

 <xsl:template match="unordered_list/list_element"/>

 <xsl:template match="unordered_list/list_element[1]">
  <ul>
   <xsl:apply-templates mode="list"
        select=".|following-sibling::*"/>
  </ul>
 </xsl:template>

 <xsl:template mode="list" match="unordered_list/list_element">
  <li><xsl:apply-templates/></li>
 </xsl:template>
</xsl:stylesheet>