EXSL <func:result> returning a node set

I've got a problem with EXSLT functions, I hope someone will be able
to help me,

I think I managed to get EXSLT's <func:result> to return a node set
but I don't seem able to use predicates on the returned set.

Here's my functions:

   <func:function name="pcpfunc:date">
       <xsl:param name="el"/>
       <func:result>
            <xsl:variable name="dateset" select="str:tokenize($el, ', ')"/>
            <mydate>
                <xsl:value-of select="$dateset[3]"/>
                <xsl:value-of select="$dateset[1]"/>
                <xsl:if test="$dateset[2] &lt; 10">0</xsl:if><xsl:value-of select="$dateset[2]"/>
            </mydate>
       </func:result>
   </func:function>

   <xsl:template match="*" mode="pcpdatefunc">
       <xsl:copy-of select="pcpfunc:date(.)"/>
   </xsl:template>

   <func:function name="pcpfunc:ordered">
       <xsl:param name="node-set"/>
       <func:result>
            <xsl:apply-templates select="$node-set" mode="pcpdatefunc">
                <xsl:sort select="pcpfunc:date(.)" order="descending"/>
            </xsl:apply-templates>
       </func:result>
   </func:function>


The function pcpfunc:ordered is supposed to return the transformed
node set that is passed in, the transformation causes date fields in a
specific format to be translated into a YYYYMMDD format

If one uses it like this:

   <xsl:value-of select="pcpfunc:ordered(/el1/el2/date)"/>

it works correctly, but if you use it like this:

   <xsl:value-of select="pcpfunc:ordered(/el1/el2/date)[1]"/>

Clearly, that should pull off the most recent date. But (with libxml2)
it fails.

I've fixed my immediate problem by having another function, like this:

   <func:function name="pcpfunc:newest">
        <xsl:param name="node-set"/>
        <func:result>
             <xsl:apply-templates select="$node-set[1]" mode="pcpdatefunc">
                 <xsl:sort select="pcpfunc:date(.)" order="descending"/>
             </xsl:apply-templates>
        </func:result>
   </func:function>


But it seems a pity to not be able to compose these functions when
dealing with node-sets.

Am I being over-optimistic? Or is it possible? If so: how?



Nic Ferrier
http://www.tapsellferrier.co.uk


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