XSLT Grouping Siblings

Question

I am trying to group sibling data in an XML file.

Given :

<?xml version="1.0" encoding="UTF-8"?>
<data>
    <competition>
        <timeline>10:00</timeline>
        <fixture>team a v team b</fixture>
        <fixture>team c v team d</fixture>
        <timeline>12:00</timeline>
        <fixture>team e v team f</fixture>
        <timeline>16:00</timeline>
        <fixture>team g v team h</fixture>
        <fixture>team i v team j</fixture>
        <fixture>team k v team l</fixture>
    </competition>
</data>

I am trying to produce :

<?xml version="1.0" encoding="UTF-8"?>
<data>
    <competition>
        <timeline time="10:00">
            <fixture>team a v team b</fixture>
            <fixture>team c v team d</fixture>
        </timeline>
        <timeline time="12:00">
            <fixture>team e v team f</fixture>
        </timeline>
        <timeline time="16:00">
            <fixture>team g v team h</fixture>
            <fixture>team i v team j</fixture>
            <fixture>team k v team l</fixture>
        </timeline>
    </competition>
</data>

I am using the following XSLT:

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

    <xsl:template match="competition" >

        <xsl:apply-templates select="timeline" />

    </xsl:template>

    <xsl:template match="timeline">
        <timeline>
            <xsl:attribute name="time" >
                <xsl:value-of select="." />
            </xsl:attribute>

            <xsl:apply-templates select="following-sibling::*" mode="copy"/>

        </timeline>
    </xsl:template>

    <xsl:template match="fixture" mode="copy">
        <fixture>
            <xsl:value-of select="." />
        </fixture>
    </xsl:template>

    <xsl:template match="timeline" mode="copy">
        <xsl:apply-templates select="following-sibling::*" mode="null" />
    </xsl:template>

    <xsl:template match="*" mode="null">
    </xsl:template>
</xsl:stylesheet>

My problem is that it is not stopping processing fixture nodes when it gets to the next timeline

Answer 1

This is easy to do when the following is true (which I assume it is):

• all <timeline>s within a <competition> are unique
• only the <fixture>s right after a given <timeline> belong to it
• there is no <fixture> without a <timeline> element before it

This XSLT 1.0 solution:

<xsl:stylesheet
  version="1.0"
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
>

  <xsl:key name="kFixture" 
           match="fixture" 
           use="generate-id(preceding-sibling::timeline[1])" 
  />

  <xsl:template match="data">
    <xsl:copy>
      <xsl:apply-templates select="competition" />
    </xsl:copy>
  </xsl:template>

  <xsl:template match="competition">
    <xsl:copy>
      <xsl:apply-templates select="timeline" />
    </xsl:copy>
  </xsl:template>

  <xsl:template match="timeline">
    <xsl:copy>
      <xsl:attribute name="time">
        <xsl:value-of select="." />
      </xsl:attribute>
      <xsl:copy-of select="key('kFixture', generate-id())" />
    </xsl:copy>
  </xsl:template>

</xsl:stylesheet>

produces:

<data>
  <competition>
    <timeline time="10:00">
      <fixture>team a v team b</fixture>
      <fixture>team c v team d</fixture>
    </timeline>
    <timeline time="12:00">
      <fixture>team e v team f</fixture>
    </timeline>
    <timeline time="16:00">
      <fixture>team g v team h</fixture>
      <fixture>team i v team j</fixture>
      <fixture>team k v team l</fixture>
    </timeline>
    </competition>
</data>

Note the use of an <xsl:key> to match all <fixture>s that belong to ("are preceded by") a given <timeline>.

A slightly shorter but less obvious solution would be a modified identity transform:

<xsl:stylesheet
  version="1.0"
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
>

  <xsl:key name="kFixture" 
           match="fixture" 
           use="generate-id(preceding-sibling::timeline[1])" 
  />

  <xsl:template match="* | @*">
    <xsl:copy>
      <xsl:apply-templates select="*[not(self::fixture)] | @*" />
    </xsl:copy>
  </xsl:template>

  <xsl:template match="timeline">
    <xsl:copy>
      <xsl:attribute name="time">
        <xsl:value-of select="." />
      </xsl:attribute>
      <xsl:copy-of select="key('kFixture', generate-id())" />
    </xsl:copy>
  </xsl:template>

</xsl:stylesheet>

Answer 2

Here is my attempt. One assumption I have made which simplifies things is that timeline elements with a specific text value are already unique.

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

  <xsl:template match="/data">
    <data>
      <xsl:apply-templates select="competition" />
    </data>
  </xsl:template>

  <xsl:template match="competition">
    <xsl:for-each select="timeline">
      <timeline time="{text()}">
        <xsl:copy-of
          select="./following-sibling::fixture[count(preceding-sibling::timeline[1] | current()) = 1]" />
      </timeline>
    </xsl:for-each>
  </xsl:template>

</xsl:stylesheet>

The above is edited to use current() instead of a variable as per Tomalak's suggestion.