XSLT : how to know I went inside any of several for-each ?

Question

I have several <xsl:for-each/> which run the one after the other. I would like, at the end, to do something if I did not pass in any of them. For only one for-each, I can manage to make a <xsl:choose/> with an appropriate test based on the selector in the for-each, but for a lot of them, it begins to be very ugly.

Has anyone a solution for keeping track of a passing through several for-each ?

Answer 1

Assuming you have something like:

<xsl:for-each select="foo[@bar]">
    <!-- do stuff for foo elements having a bar attribute -->
</xsl:for-each>

<xsl:for-each select="foo[@fap]">
    <!-- do stuff for foo elements having a fap attribute -->
</xsl:for-each>

then you can create the union of the nodesets selected in each for-each and, if that nodeset is empty, do something else:

<xsl:if test="not(foo[@bar] | foo[@fap])">
    <!-- there weren't any nodes matched above, so do something else -->
</xsl:if>

EDIT: In the case where your nodeset-selecting XPath expressions are very complex, you can make things easier to follow by using variables with meaningful names; for example:

<xsl:variable name="articles" select="stuff/that/is[3]/very[@deeply-nested and position() &lt; 5]"/>
<xsl:variable name="comments" select="stuff/that/is[1]/very[@deeply-nested and position() &gt; 27]"/>
<xsl:variable name="rants" select="stuff/that/is[17]/even/more[@deeply-nested and position() &lt; 5]/with/some/more/nesting"/>

<h1>Ramblings</h1>

<xsl:for-each select="$articles">
    <!-- do stuff with articles -->
    <h2>Article <xsl:value-of select-"position()"/></h2>
</xsl:for-each>

<xsl:for-each select="$comments">
    <!-- do stuff with comments -->
    <h2>Comment <xsl:value-of select-"position()"/></h2>
</xsl:for-each>

<xsl:for-each select="$rants">
    <!-- do stuff with rants -->
    <h2>Rant <xsl:value-of select-"position()"/></h2>
</xsl:for-each>

<xsl:if test="not($articles | $comments | $rants)">
    <!-- nobody had anything to say... -->
    <h2>Nothing to see here</h2>
</xsl:if>

Answer 2

You could use <xsl:variable> to set a local variable according to which for-each you did enter, and then test if with <xsl:if> at the end.