Repost:  Sorry, I posted the first message as a reply...

I know that this error has been addressed on this list before, but I don't
think it has been answered in this context.

I have been working on a set of svg graphing (xslt) utilities that I'd like
to make publicly available once my senior design project is complete, but
I've run into a slight snag.  I wanted to be able to customize different
parameters in multiple ways.  Below is listed a small segment of my xml and
xslt.

---- graph.xml ----
<?xml version="1.0" encoding="UTF-8"?> 
<graph type="pie"> 
 <!-- Graph data goes here --> 
</graph> 

---- graph.xslt ----
<?xml version="1.0" encoding="UTF-8"?> 
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"> 
 <xsl:output method="xml" version="1.0" encoding="UTF-8" indent="yes"/> 

 <xsl:template match="graph"> 
  <xsl:call-template name="drawGraph"> 
   <!-- Optional parameters to alter graph --> 
   <xsl:with-param name="type" select="'bar'"/> 
  </xsl:call-template> 
 </xsl:template> 

 <xsl:template name="drawGraph"> 
  <xsl:variable name="graph" select="." /> 
  <xsl:param name="type"> 
   <xsl:choose> 
    <xsl:when test="not(string-length($graph/@type) = 0)"> 
     <xsl:value-of select="$graph/@type" /> 
    </xsl:when> 
    <xsl:otherwise> x-y</xsl:otherwise>
   </xsl:choose> 
  </xsl:param> 
  <type> 
   <xsl:value-of select="$type"/> 
  </type> 
 </xsl:template> 

</xsl:stylesheet> 

---- output.xml ----
<?xml version="1.0" encoding="UTF-8"?> 
<type> bar</type>

Although you would probably never include a parameter in both the calling
template and the xml data, I have included both to demonstrate the use.  The
passed template param should win however.  When evaluating this with XML
Spy, in debug mode, it works exactly as I want it too.  I can change the
value of @type either while calling the template, or directly from the xml
data.  If neither parameter was provided, the template assumes a default.

Xalan and MSXML fail completely.  If I place my params inside the choose,
then they aren't recognized, as should be, but it doesn't seem to like my
nested choose for the param either.  I suspect that this structure is the
source of my error: xsl:param may not be used here.

If anyone has suggestions as to how I can make this work, I'm always eager
to learn.  I believe I could use a variable to make this work, but then I
wouldn't be able to change it from the template, right?

Ryan Beesley
Rbeesley@[...].org
Founder, Atum Innovations



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