RE: [xsl] Sort problem

["Michael Kay" <mhk@xxxxxxxxx>]

A NullPointerException occurring within the code of your XSLT processor is a
bug, and should be notified to the vendor. 

The free-standing version of Xalan is reputed to be more reliable than the
one bundled with JDK 1.4.

Michael Kay 

> -----Original Message-----
> From: Paolo Noya [mailto:paolo.noya@xxxxxxxxxxx] 
> Sent: 10 September 2004 16:20
> To: xsl-list@xxxxxxxxxxxxxxxxxxxxxx
> Subject: [xsl] Sort problem
> 
> Hi,
> I've a problem during sort node with xalan-j version 
> 2.4.1(bundle with jdk 1.4.2_05). 
> I have an XML like this:
> =======================
> <?xml version="1.0"?>
> <Peoples>
>     <Person>
>         <Name>Johnson</Name>
>         <Level>foo</Level>
>     </Person>
>     <Person>
>         <Name>Smith</Name>
>         <Level>baz</Level>
>     </Person>
>     <Person>
>         <Name>White</Name>
>         <Level>foo</Level>
>     </Person>
>     <Person>
>         <Name>Brown</Name>
>     </Person>
>     <Person>
>         <Name>Black</Name>
>         <Level>bar</Level>
>     </Person>
> </Peoples>
> =======================
> and I want sort by level and then by name giving a rule for 
> mapping level with an arbitrary number.
> I wrote an xml like this:
> =======================
> <?xml version="1.0"?>
> <xsl:stylesheet  
> xmlns:xsl="http://www.w3.org/1999/XSL/Transform"; version="1.0"
>   xmlns:this="http://localhost/"; exclude-result-prefixes="this"
> >
>  
> <this:Levels>
>     <Level pos="0"/><!--dummy level-->
>     <Level pos="1">foo</Level>
>     <Level pos="2">bar</Level>
>     <Level pos="3">baz</Level>
> </this:Levels>
>  
> <xsl:variable name="levels" 
> select="document('')/xsl:stylesheet/this:Levels"/>
>  
> <xsl:template match="/Peoples">
>     <xsl:apply-templates select="Person">
>         <xsl:sort data-type="number" 
> select="number($levels/Level[.=current()/Level]/@pos)"/>
>         <xsl:sort select="Name"/>
>     </xsl:apply-templates>
> </xsl:template>
>  
> <xsl:template match="Person">
>     <xsl:value-of select="Name"/><br/>
> </xsl:template>
>  
> </xsl:stylesheet>
> =======================
>  
> during transfom, the element  <xsl:sort data-type="number" 
> select="number($levels/Level[.=current()/Level]/@pos)"/> 
> produce an excepiton 
> javax.xml.transform.TransformerException: 
> java.lang.NullPointerException
> 
> but if i print the <xsl:value-of 
> select="number($levels/Level[.=current()/Level]/@pos)"/> in 
> "Person" template I got the correct value.
> If apply the same transform directly with my IE6.0 (so using 
> msxml transformer) i obtain the correct result.
>  
> What's wrong?
> It is my error suppose that the current() function inside 
> sort element refer to selected node in apply-templates?
>  
> regards,
> Paolo