Re: [xsl] Distinct list problem

["G. Ken Holman" <gkholman at CraneSoftwrights dot com>]

At 2002-01-18 14:53 +0100, Henk Meulekamp wrote:
>I'm trying to get a list of id's where each id is represented once out of
>the xml below. Is it possible?

Yes, and there are a few ways you can do it.

>The ouput I want is:
>
>20
>21
>22

This is a classic "grouping" problem.  Two of the ways you can do it are 
with key tables or variables, both illustrated below using *only* XSLT 1.0 
functionality and no vendor extensions.

In each case one is relying on the generate-id() function to uniquely 
identify nodes from a set.  One can use a key table for the set, or if you 
are using XT one can use a variable for the set.  When doing grouping of 
subsets of the tree, using a variable for the set is often more convenient 
than using the key table.

I hope this helps.

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


T:\ftemp>type henk.xml
<CONTRACT IDCONTRACT="2" CCONTRACTNUMBER="1.1" CPRODUCT="JORISTEST"
DECQUANTITY="1000.000" CUNIT="MT">
<DELIVERY IDDELIVERY="1" NUMLOADINGASSIGNMENT="1" IDTESTREPORT="2">
   <ATTRIBUTEQUALITY IDTESTTYPE="20" />
   <ATTRIBUTEQUALITY IDTESTTYPE="21" />
   </DELIVERY>
<DELIVERY IDDELIVERY="2" NUMLOADINGASSIGNMENT="1234" IDTESTREPORT="1">
   <ATTRIBUTEQUALITY IDTESTTYPE="21" />
   <ATTRIBUTEQUALITY IDTESTTYPE="20" />
   <ATTRIBUTEQUALITY IDTESTTYPE="21" />
   <ATTRIBUTEQUALITY IDTESTTYPE="21" />
   <ATTRIBUTEQUALITY IDTESTTYPE="20" />
   </DELIVERY>
<DELIVERY IDDELIVERY="4" NUMLOADINGASSIGNMENT="4" IDTESTREPORT="20">
   <ATTRIBUTEQUALITY IDTESTTYPE="22" />
   <ATTRIBUTEQUALITY IDTESTTYPE="21" />
   <ATTRIBUTEQUALITY IDTESTTYPE="20" />
   </DELIVERY>
<DELIVERY IDDELIVERY="6" NUMLOADINGASSIGNMENT="6" IDTESTREPORT="23">
   <ATTRIBUTEQUALITY IDTESTTYPE="21" />
   <ATTRIBUTEQUALITY IDTESTTYPE="20" />
   </DELIVERY>
</CONTRACT>

T:\ftemp>type henk.xsl
<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform";
                 version="1.0">

<xsl:output method="text"/>

<xsl:key name="ids" match="ATTRIBUTEQUALITY" use="@IDTESTTYPE"/>

<xsl:template match="/">

   <xsl:text>using keys:
</xsl:text>
   <xsl:for-each select="//ATTRIBUTEQUALITY
                         [generate-id(.)=
                          generate-id(key('ids',@IDTESTTYPE))]">
     <xsl:value-of select="@IDTESTTYPE"/>
     <xsl:text>
</xsl:text>
   </xsl:for-each>

   <xsl:text>

using variables:
</xsl:text>
   <xsl:variable name="ids" select="//ATTRIBUTEQUALITY"/>
   <xsl:for-each select="$ids">
     <xsl:if test="generate-id(.)=
                   generate-id($ids[@IDTESTTYPE=current()/@IDTESTTYPE])">

       <xsl:value-of select="@IDTESTTYPE"/>
       <xsl:text>
</xsl:text>
     </xsl:if>
   </xsl:for-each>

</xsl:template>

</xsl:stylesheet>

T:\ftemp>saxon henk.xml henk.xsl
using keys:
20
21
22


using variables:
20
21
22


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