XSLT <xsl:key> fails when indexing 2 identical nodesets -

hello first question on stackoverflow :-)

i've experienced strange behaviour xsl:key function in xslt, wich bit hard explain, easy demonstrate.

when i'm indexing 2 different identical nodesets xsl:key element, fails index them properly.

in test example want know how many cells have been indexed each table. here first input 2 identical tables (exept @id):

<?xml version="1.0" encoding="utf-8"?> <test>     <table id="table1">         <cell>cell 1</cell>         <cell>cell 2</cell>         <cell>cell 3</cell>     </table>     <table id="table2">         <cell>cell 1</cell>         <cell>cell 2</cell>         <cell>cell 3</cell>     </table> </test> 

then second input different content second table (first cell contains "cell_1" underscore):

<?xml version="1.0" encoding="utf-8"?> <test>     <table id="table1">         <cell>cell 1</cell>         <cell>cell 2</cell>         <cell>cell 3</cell>     </table>     <table id="table2">         <cell>cell_1</cell>         <cell>cell 2</cell>         <cell>cell 3</cell>     </table> </test> 

here xslt. i'm counting each table element, number of cells sharing same current parent::table.

<?xml version="1.0" encoding="utf-8"?> <xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/xsl/transform" version="1.0">      <xsl:key name="cell" match="//cell" use="parent::table"/>      <xsl:template match="//test">         <xsl:copy>             <xsl:apply-templates/>         </xsl:copy>     </xsl:template>      <xsl:template match="table">         <numcells id_table="{@id}">             <xsl:value-of select="count(key('cell', .))"/>         </numcells>     </xsl:template>  </xsl:stylesheet> 

and here first output 2 identical tables. shows 6 cells in each table instead of 3.

<?xml version="1.0" encoding="utf-8"?> <test>     <numcells id_table="table1">6</numcells>     <numcells id_table="table2">6</numcells> </test> 

and second output 2 different tables. shows right number of 3 cells each table.

<?xml version="1.0" encoding="utf-8"?> <test>     <numcells id_table="table1">3</numcells>     <numcells id_table="table2">3</numcells> </test> 

it may related xslt processor, i've tested saxon, xalan , xsltproc same result.

i've seen around problem using @id:

<xsl:key name="cell" match="//cell" use="parent::table/@id"/> 

and then:

<xsl:value-of select="count(key('cell', @id))"/> 

but i'm still wondering causing behaviour. explanations!

a key value primitive value string or number, not node itself. if want key on node identity use use="generate-id(parent::table)".

your current key string value of table element , concatenation of text descendant nodes first sample key values like

cell 1 cell 2 cell 3 

you want group or key based on identity of node, not based on string contents. use generate-id or use id attribute present on table elements, have found out.