Re: AW: [xsl] XPATH restricting preceding nodes

["G. Ken Holman" <gkholman@xxxxxxxxxxxxxxxxxxxx>]

At 2003-09-10 14:45 +0200, Kloeck, Erwin wrote:
> your solution works. This was what I needed. Now I have to read a little 
> about what xls:key does to also understand this. :-)

Actually, when doing subgrouping on a tree you don't *always* have to use keys.

When I teach grouping in XSLT 1.0 I go through three different methods: by 
axes, by variables and by keys.  I find that multi-level grouping or 
subgrouping can be a lot easier by variables when you don't need to act on 
node sets.

But I also go over keys as a standalone concept, not just in grouping ... a 
week from Monday we have a public European delivery of our courses that you 
might be interested in where we go over every element, attribute and 
function of both XSLT and XPath, and in a separate course that week, every 
formatting object of XSL-FO.

I hope the example below helps.

.................... Ken

T:\ftemp>type erwin.xml
<?xml version="1.0" encoding="iso-8859-1"?>
<top>
        <page>
                <entry text='aaa'/>
                <entry text='bbb'/>
                <entry text='aaa'/>
        </page>
        <page>
                <entry text='ccc'/>
                <entry text='bbb'/>
                <entry text='ccc'/>
        </page>
</top>

T:\ftemp>type erwin.xsl
<?xml version="1.0" encoding="iso-8859-1"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform";
                version="1.0">

<xsl:output method="text"/>

<xsl:template match="top">
 <xsl:for-each select="page">
    Page <xsl:value-of select="position()"/>:
  <xsl:variable name="entries" select="entry"/>
  <xsl:for-each select="$entries">
    <xsl:if 
test="generate-id(.)=generate-id($entries[@text=current()/@text])">
      Entry: <xsl:value-of select="@text"/>
    </xsl:if>
  </xsl:for-each>
 </xsl:for-each>
</xsl:template>

</xsl:stylesheet>
T:\ftemp>saxon erwin.xml erwin.xsl

    Page 1:

      Entry: aaa
      Entry: bbb
    Page 2:

      Entry: ccc
      Entry: bbb
T:\ftemp>


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G. Ken Holman                 mailto:gkholman@xxxxxxxxxxxxxxxxxxxx
Crane Softwrights Ltd.          http://www.CraneSoftwrights.com/s/
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