I need to be able to count the number of items that appear in the xml somewhere else. I'm traversing each item want to check if its in the lookup as below

<root>
  <lookup>
     <id>
  <item>
     <id2>

<xsl:for-each select="//item">

  <xsl:value-of select="count(?????)"/>
</xsl:for-each>

How would i do this without defining a variable (i'm using a simple example). I'm stuck I can do pretty much anything else with the XSLT but this logic doesn't seem to be clicking

Thanks
Ash

I can't see why on earth you would want a variable to do simple counting. You just have to count the items selected by some path expression. But I can't write that path expression for you, since you haven't explained clearly what your source data structure is and what the condition is for items to be counted.

Michael Kay
http://www.saxonica.com/
Author, XSLT Programmer's Reference and XPath 2.0 Programmer's Reference

Ok so say I want to do the following:

<xsl:value-of select="count(/root/lookup/id=<id2>)"/>

So essentially I want to go through each item and find how many entries there are in the lookup nodelist.

So if i was using a variable i'd do it like
<xsl:for-each select="//item">
  <xsl:param name="id2" select="id2"/>
  <xsl:value-of select="count(/root/lookup/id=$id2)"/>
</xsl:for-each>

however theres some cases when you can't define variables so the above wont work.

<root>
  <lookup>
     <id> (/root/lookup/id)
  <item>
     <id2> (/root/item/id2)

Please show me a specific example, don't just mumble that there are cases that don't work.

I've no idea what this notation is supposed to mean:

<root>
  <lookup>
     <id> (/root/lookup/id)
  <item>
     <id2> (/root/item/id2)

Michael Kay
http://www.saxonica.com/
Author, XSLT Programmer's Reference and XPath 2.0 Programmer's Reference

XML
===

<root>
  <lookup>
     <id>12345</id>
     <id>12345</id>
     <id>21345</id>
     <id>2345</id>
  </lookup>
  <item>
     <id2>12345</id2>
     <description>widget</description>
  </item>
  <item>
     <id2>31244</id2>
     <description>bolt</description>
  </item>
</root>


PSEUDO CODE
===========
if theres any matching ids in the lookup node to the items id then output the header.


<xsl:if test="count(/root/lookup/id = //item/id2) > 0">
   [header html]
</xsl:if>

You don't need to count nodes for that: you can just write

<xsl:if test="/root/lookup/id = //item/id2">
   [header html]
</xsl:if>

You could of course compute the count if you needed it, for example

count(//item/id2[. = /root/lookup/id])



Michael Kay
http://www.saxonica.com/
Author, XSLT Programmer's Reference and XPath 2.0 Programmer's Reference