XSLT Cookbook

Deepening an XML Hierarchy

Problem

You have a poorly designed document that can use extra structure.^[13]

Solution

This is the opposite problem from that solved in Recipe 6.7. Here you need to add additional structure to a document, possibly to organize its elements by some additional criteria.

Add structure based on existing data

This type of deepening transformation example undoes the flattening transformation performed in Recipe 6.7:

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
   
  <xsl:import href="copy.xslt"/>
  
  <xsl:output method="xml" version="1.0" encoding="UTF-8" indent="yes"/>
  <xsl:strip-space elements="*"/>
   
  <xsl:template match="people">
    <union>
       <xsl:apply-templates select="person[@class = 'union']" />
    </union>
    <salaried>
       <xsl:apply-templates select="person[@class = 'salaried']" />
    </salaried>
  </xsl:template>  
   
</xsl:stylesheet>

Add structure to correct a poorly designed document

In a misguided effort to streamline XML, some people attempt to encode information by inserting sibling elements rather than parent elements.^[14]

For example, suppose someone distinguished between union and salaried employees in the following way:

<people>
  <class name="union"/>
  <person>
    <firstname>Warren</firstname>
    <lastname>Rosenbaum</lastname>
    <age>37</age>
    <height>5.75</height>
  </person>
...
  <person>
    <firstname>Theresa</firstname>
    <lastname>Archul</lastname>
    <age>37</age>
    <height>5.5</height>
  </person>
  <class name="salaried"/> <person> <firstname>Sal</firstname> <lastname>Mangano</lastname> ...