Re: [xsl] Re: [xslt transform & grouping] Using the Muenchian Method?

[David Carlisle <davidc@xxxxxxxxx>]

You get
$ saxon filter.xml filter.xsl
<?xml version="1.0" encoding="UTF-8"?>
<Documents>
   <Document name="sub">
      <Article title="1.1" info="sub" filter="food"/>
   </Document>
   <Document name="main">
      <Article title="1.2" info="main" filter="food"/>
      <Article title="2.2" info="main" filter="food"/>
   </Document>
   <Document name="child"/>
</Documents>

because of the different ways you filter.
on document you allow "" but in
<xsl:copy-of select="key('by-info',@info)[@filter=$filter]"/>
you don't.

I think that _is_ what you want, so in your for-each, 

<xsl:for-each select="Document[@filter='' or 
@filter=$filter]/Article[generate-id()=generate-id(key('by-info',@info)[@filter='' 
or @filter=$filter])]">

you want to make sure that you always have at least one eleemnt in the
key that really has the filter value and not just "" so that
<xsl:copy-of select="key('by-info',@info)[@filter=$filter]"/>
always produces something.

you can do that by making the filters on the key() match,
delete     @filter='' or 

<xsl:for-each select="Document[@filter='' or 
@filter=$filter]/Article[generate-id()=generate-id(key('by-info',@info)[@filter=$filter])]">

and you get

$ saxon filter.xml filter.xsl
<?xml version="1.0" encoding="UTF-8"?>
<Documents>
   <Document name="sub">
      <Article title="1.1" info="sub" filter="food"/>
   </Document>
   <Document name="main">
      <Article title="1.2" info="main" filter="food"/>
      <Article title="2.2" info="main" filter="food"/>
   </Document>
</Documents>

David

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