Re: [xsl] Grouping by attribute

Subject: Re: [xsl] Grouping by attribute
From: Martin Honnen <Martin.Honnen@xxxxxx>
Date: Mon, 19 Oct 2009 15:12:56 +0200
Jostein Austvik Jacobsen wrote:
I've got this flat-structured XML:

<document>
  <metaData>
    <title>Title</title>
    <publisher>Publisher</publisher>
  </metaData>
  <contentSection>
    <p>text</p>

    <headline level="2">Headline</headline>
    <p>text</p>
    <p>text</p>

    <headline level="2">Section</headline>
    <p>text</p>
    <pagenum id="page2"/>
    <p>text</p>
    <headline level="3">Subsection</headline>
    <p>text</p>

    <headline level="2">Section</headline>
    <p>text</p>
    <p>text</p>
  </contentSection>
</document>

And want it transformed to this XML:

<body>
  <level1>
    <h1>Title</h1>
    <p>text</p>

    <level2>
      <h2>Headline</h2>
      <p>text</p>
      <p>text</p>
    </level2>

    <level2>
      <h2>Section</h2>
      <p>text</p>
      <pagenum id="page2"/>
      <p>text</p>
      <level3>
        <h3>Subsection</h3>
        <p>text</p>
      </level3>
    </level2>

    <level2>
      <h2>Section</h2>
      <p>text</p>
      <p>text</p>
    </level2>
  </level1>
</body>

How would I do that using XSLT? XSLT 2.0 solutions are ok.

The following stylesheet creates above output structure, only white space/indenting is different from what you posted:


<xsl:stylesheet
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform";
  version="2.0"
  xmlns:xs="http://www.w3.org/2001/XMLSchema";
  xmlns:mf="http://example.com/2009/mf";
  exclude-result-prefixes="xs mf">

  <xsl:output indent="yes"/>
  <xsl:strip-space elements="*"/>

<xsl:function name="mf:group" as="node()*">
<xsl:param name="nodes" as="node()*"/>
<xsl:param name="level" as="xs:integer"/>
<xsl:for-each-group select="$nodes" group-starting-with="headline[@level = $level]">
<xsl:choose>
<xsl:when test="self::headline[@level = $level]">
<xsl:element name="level{$level}">
<xsl:element name="h{$level}">
<xsl:value-of select="."/>
</xsl:element>
<xsl:sequence select="mf:group(current-group() except ., $level + 1)"/>
</xsl:element>
</xsl:when>
<xsl:otherwise>
<xsl:copy-of select="current-group()"/>
</xsl:otherwise>
</xsl:choose>
</xsl:for-each-group>
</xsl:function>


<xsl:template match="document">
<xsl:variable name="v1">
<headline level="1"><xsl:value-of select="metaData/title"/></headline>
<xsl:copy-of select="contentSection/node()"/>
</xsl:variable>
<body>
<xsl:sequence select="mf:group($v1/node(), 1)"/>
</body>
</xsl:template>


</xsl:stylesheet>



--

	Martin Honnen
	http://msmvps.com/blogs/martin_honnen/

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