Hi all,
Consider the following XML:
<?xml version="1.0" encoding="UTF-8"?>
<document>
<chapter name="a">
<section ref="1" />
<section ref="2" />
</chapter>
<chapter name="b">
<section ref="1" />
<section ref="2" />
</chapter>
</document>
I have implemented the following extension function, just to trace the
extension calls:
public static boolean dummy(final boolean flag) {
System.out.println(flag);
return flag;
}
and the following XSL:
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform";
xmlns:utils="my.XslUtils"
xmlns:xalan="http://xml.apache.org/xalan";
extension-element-prefixes="utils">
<xsl:output method="xml" indent="yes" encoding="UTF-8"
media-type="text/xml" xalan:indent-amount="2" />
<xsl:strip-space elements="*" />
<xsl:template match="/document">
<document-report>
<xsl:for-each select="descendant::section[utils:dummy(true())][1]">
<section-report ref="{...@ref}"
proc-ref="{ancestor::chapter/@name}" />
</xsl:for-each>
</document-report>
</xsl:template>
</xsl:stylesheet>
In this case the console will show that dummy() was called *once* and
the output report will be:
<?xml version="1.0" encoding="UTF-8"?>
<document-report xmlns:xalan="http://xml.apache.org/xalan";>
<section-report proc-ref="a" ref="1"/>
</document-report>
The problem is with the variants of
descendant::section[utils:dummy(true())][1]:
1. xsl variables:
<xsl:variable name="sections" select="descendant::section" />
and then use this XPath expression instead
xalan:nodeset($sections)[utils:dummy(true())][1]
then the dummy() function will be called 4 times (while the output xml
will remain the same) !
2. paths with more than one fragments:
(chapter/section[utils:dummy(true())])[1]
(chapter/section)[utils:dummy(true())][1]
((chapter/section)[utils:dummy(true())])[1]
in these cases the dummy() function is called 4 times too (while the
output xml still remains the same) !
What is the reason of this behavior?
Do I miss something?
Regards,
Adrian.
