Is there a way to conditionally sort in xslt? - xpath

Question

I need to sort some content but only when an attribute is equal to CAT. I think I should be able to pass a property from my ant build file to the use-when attribute but it is not working. Any help would be appreciated
Here is the xslt that I have:
<xsl:for-each select="document(#fileRef)/foo/bar">
<xsl:sort select="translate(child::Title/text(), '>', '')" order="ascending" use-when="system-property('customerCode')='CAT'"
collation="http://www.w3.org/2005/xpath-functions/collation/html-ascii-case-insensitive"/>
<!-- do some stuff here -->
</xsl:for-each>

Answer 1

Using oXygen I got the following to work in an Ant file:
<xslt in="sample1.xml" out="sample1-transformed.xml" force="true" style="sheet1.xsl">
<factory name="net.sf.saxon.TransformerFactoryImpl"/>
<sysproperty key="cat" value="bar"/>
</xslt>
XML sample1.xml is e.g.
<?xml version="1.0" encoding="UTF-8"?>
<root>
<item>c</item>
<item>a</item>
</root>
XSLT is
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
exclude-result-prefixes="#all"
version="3.0">
<xsl:mode on-no-match="shallow-copy"/>
<xsl:output method="xml" indent="yes"/>
<xsl:template match="/">
<xsl:comment select="system-property('cat')"/>
<xsl:next-match/>
</xsl:template>
<xsl:template match="root">
<xsl:copy>
<xsl:apply-templates select="item">
<xsl:sort select="." use-when="system-property('cat') = 'foo'"/>
</xsl:apply-templates>
</xsl:copy>
</xsl:template>
</xsl:stylesheet>
and then the output items are sorted only if the Ant sets e.g. <sysproperty key="cat" value="foo"/>.