Question

I have an XSLT in which I create (from the input data) intermediary variables like the following (hard-coded example, but dynamic in nature):

<xsl:variable name="variableX">
    <ValidCode CodePart="CP1" Code="C1"/>
    <ValidCode CodePart="CP2" Code="C2"/>
    <ValidCode CodePart="CP1" Code="C3"/>
    <ValidCode CodePart="CP2" Code="C4"/>
    <ValidCode CodePart="CP2" Code="C5"/>
</xsl:variable>

I wish to loop over the distinct occurrences of CodePart values. In XSLT 2.0 it’s easy:

<xsl:for-each select="distinct-values($variableX/ValidCode/@CodePart)">...</xsl:for-each>

But how best do this in XSLT 1.0?
Note that I can’t use a key, as it’s a dynamically determined variable and not part of the input file.

My input file does contain a list of all possible code parts as follows:

<root>
    <CodePart><value>CP1</value></CodePart>
    <CodePart><value>CP2</value></CodePart>
    <CodePart><value>CP3</value></CodePart>
</root>

So I thought of looping over //CodePart/value instead, ensuring uniqueness for starters. But then I need some Xpath expression that includes the condition

“value occurs in the node-set of all $variableX/ValidCode/@CodePart values”

and use something like

<xsl:for-each select="//CodePart[..condition..]/value">...</xsl:for-each>

Is there a simple form of the Xpath expression I am looking for?
Or is another approach preferable?

Answer 1

I don’t think you can use directly an XPath – but you should be able to check for only the valid values like this:

<xsl:for-each select="//CodePart/value">
  <xsl:variable name="CodePart" select="."/>
  <xsl:if test="$variableX/ValidCode[@CodePart=$CodePart]">
    . . .
  </xsl:if>
</xsl:for-each> 

or more simply (thanks to the comments):

<xsl:for-each select="//CodePart/value">
  <xsl:if test="$variableX/ValidCode[@CodePart=current()]">
    . . .
  </xsl:if>
</xsl:for-each> 

If $variableX is not a node set but an XML fragment it needs to be converted to a node set – this is implementation-dependent, using Microsoft processors:

<xsl:for-each select="//CodePart/value" xmlns:msxsl="urn:schemas-microsoft-com:xslt">
  <xsl:if test="msxsl:node-set($variableX)/ValidCode[@CodePart=current()]">
    . . .
  </xsl:if>
</xsl:for-each>