Question

Is it possible in XSLT to sort in alphabetical order, with 5 items as “preferred”.

i.e. given

<teams>
<team id="142" name="Scotland" />
<team id="110" name="Liverpool" />
<team id="13" name="Manchester United" />
<team id="123" name="England" />
<team id="84" name="Chelsea" />
<team id="295" name="Wales" />
<team id="49" name="Arsenal" />
<team id="126" name="Northern Ireland" />
<team id="121" name="Republic of Ireland" />
<team id="42" name="Manchester City" />
<team id="298" name="Tottenham Hotspur" />
<team id="299" name="Bolton" />
</teams>

I require the national teams to be sorted first in a certain order, followed by the rest in alphabetical order:

<teams>
<team id="123" name="England" />
<team id="126" name="Northern Ireland" />
<team id="121" name="Republic of Ireland" />
<team id="142" name="Scotland" />
<team id="295" name="Wales" />
<team id="49" name="Arsenal" />
<team id="299" name="Bolton" />
<team id="84" name="Chelsea" />
<team id="110" name="Liverpool" />
<team id="42" name="Manchester City" />
<team id="13" name="Manchester United" />
<team id="298" name="Tottenham Hotspur" />
</teams>

I have been trying, but failing.

Is there a neat way to do this, or do you have to sort the national teams individually, followed by a sort which excludes all the national teams?

Answer 1

You could do this:

<xsl:stylesheet
  version="1.0"
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
  xmlns:my="http://tempuri.org"
  exclude-result-prefixes="my"
>

  <xsl:output method="xml" indent="yes" /> 

  <my:data>
    <my:nationalteams>
      <my:team id="121" /><!-- Republic of Ireland -->
      <my:team id="123" /><!-- England -->
      <my:team id="126" /><!-- Northern Ireland -->
      <my:team id="142" /><!-- Scotland -->
      <my:team id="295" /><!-- Wales -->
    </my:nationalteams>
  </my:data>

  <xsl:template match="teams">
    <xsl:copy>
      <xsl:variable name="national" select="
        document('')/*/my:data/my:nationalteams/my:team
      " />
      <!-- national teams preferred -->
      <xsl:apply-templates select="team[@id = $national/@id]">
        <xsl:sort select="@name" />
      </xsl:apply-templates>
      <!-- other teams after them -->
      <xsl:apply-templates select="team[not(@id = $national/@id)]">
        <xsl:sort select="@name" />
      </xsl:apply-templates>
    </xsl:copy>
  </xsl:template>

  <xsl:template match="team">
    <xsl:copy-of select="." />
  </xsl:template>

</xsl:stylesheet>

The whole <my:data> could be moved to a secondary XML/config file, where you can also leave off the “my” namespace.

After that, one line would need a small change:

<xsl:variable name="national" select="
  document('config.xml')/data/nationalteams/team
" />

The output of the above is somewhat unsurprising 🙂

<teams>
  <team id="123" name="England" />
  <team id="126" name="Northern Ireland" />
  <team id="121" name="Republic of Ireland" />
  <team id="142" name="Scotland" />
  <team id="295" name="Wales" />
  <team id="49" name="Arsenal" />
  <team id="299" name="Bolton" />
  <team id="84" name="Chelsea" />
  <team id="110" name="Liverpool" />
  <team id="42" name="Manchester City" />
  <team id="13" name="Manchester United" />
  <team id="298" name="Tottenham Hotspur" />
</teams>