XSLT, 2nd Edition

A Stylesheet That Uses the id() Function

Let’s look at our desired output. What we want is a simple text document that lists all of the part names for each component, which should look like this:

Here is a test of the id() function:

  Turnip Twaddler (component #C28392-33-TT) uses these parts:
    Spanner
    Feather Duster
    Grommet
    Paring Knife

  Prawn Goader (component #C28813-70-PG) uses these parts:
    Paring Knife
    Mucilage
    Ribbon Curler

...

  Olive Bruiser (component #C28772-63-OB) uses these parts:
    Pitter
    Patter

The stylesheet to generate these results is pretty straightforward:

<?xml version="1.0"?>
<!-- id1.xsl -->
<xsl:stylesheet version="2.0"
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform">

  <xsl:output method="text"/>

  <xsl:template match="/">
    <xsl:text>&#xA;Here is a test of the id() </xsl:text>
    <xsl:text>function:&#xA;</xsl:text>

    <xsl:for-each select="/parts-list/component">
      <xsl:text>&#xA;  </xsl:text>
      <xsl:value-of select="name"/>
      <xsl:text> (component #</xsl:text>
      <xsl:value-of select="@component-id"/>
      <xsl:text>) uses these parts:&#xA;    </xsl:text>
      <xsl:for-each select="id(partref/@refid)">
        <xsl:value-of select="name"/>
        <xsl:text>&#xA;    </xsl:text>
      </xsl:for-each>
    </xsl:for-each>
  </xsl:template>
</xsl:stylesheet>

We call the id() function, which returns a node-set/sequence of all the nodes that match all of the refid attributes of the <partref> elements in each component. Each item in the node-set is the actual <part> element, so the XPath expression select="name" returns the name of the ...