XSLT conditionally write to two different files - xslt-2.0

Question

I need to extract log meesages from an XML file and write them out to plain text files. The log messages come in two flavors, and I want to write them to separate files.
I have written a style sheet that does exactly what I need except that it sometimes creates empty files because the XML file may not contain messages of one type or another.
I am wondering, 1) if what I ma doing is the best method to do this, and 2) if there is a way to suppress empty files.
My sample may contain errors because it has been retyped. (the original is on a closed network)
Note: I am using XSLT 2.0 features.
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="2.0">
<xsl:output method="text" encoding="iso-8859-1" />
<xsl:param name="break" select="string('
')" />
<xs:template match="/">
<xsl:result-document method="text" href="foo.txt">
<xsl:apply-templates select="Root/a/b/c[contains(., 'foo')]" />
</xsl:reult-document>
<xsl:result-document method="text" href="bar.txt">
<xsl:apply-templates select="Root/a/b/c[not(contains(., 'foo'))]" />
</xsl:reult-document>
</xsl:template>
<xsl:template match="*">
<xsl:value-of select=concat(normalize-space(.), $break)" />
</xsl:template>
</xsl:stylesheet>

Answer 1

You could use some XSLT 2.0 stylesheet like:
<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:param name="break" select="string('
')" />
<xsl:template match="/">
<xsl:apply-templates select="Root/a/b/c"/>
</xsl:template>
<xsl:template match="/Root/a/b/c[contains(., 'foo')]">
<xsl:result-document method="text" href="foo.txt">
<xsl:next-match/>
</xsl:result-document>
</xsl:template>
<xsl:template match="/Root/a/b/c[not(contains(., 'foo'))]">
<xsl:result-document method="text" href="bar.txt">
<xsl:next-match/>
</xsl:result-document>
</xsl:template>
<xsl:template match="*">
<xsl:value-of select="concat(normalize-space(.), $break)" />
</xsl:template>
</xsl:stylesheet>
Note: Pattern matching and xsl:next-match.