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(_at_)computer(_dot_)org
Founder, Atum Innovations
XSL-List info and archive: http://www.mulberrytech.com/xsl/xsl-list