Re: question with using Muenchian/xsl:key (Re: sort/group/co

Xu, Xiaocun wrote:
>   Thanks to Jeni's suggestion, I started to apply Muenchian for grouping.
> It works well, but I have one problem: since xsl:key is top-level element, I
> can not seem to apply element scope with it.

This is *exactly* my problem with xsl:key. The only way to restrict your
key lookup to a certain node-set is to find the intersection of that
node-set and the result of a key lookup across the whole current node's
document.

The "Kaysian Method" of finding node-set intersections is:

	$set1[count(.|$set2)=count($set2)]

With your data, the indicated section will be $set1:
  <xsl:for-each select="item[count(. | key('items-by-itemid', @itemid)[1]) =1]">
                                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
And you'll need to prepare a variable for $set2 right before that:
  <xsl:variable name="this_lists_items" select="item"/>

So the for-each should look like (and I haven't tested this):
  <xsl:for-each select="item[count(.|key('items-by-itemid',@itemid)[count(.|$this_lists_items)=count($this_lists_items)][1])=1]">

Clear as mud, eh?

   - Mike
____________________________________________________________________
Mike J. Brown, software engineer at         My XML/XSL resources:
webb.net in Denver, Colorado, USA           http://www.skew.org/xml/


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