How to use an xsl variable in a javascript block - xslt

Question

I am trying to use an xsl variable in a javascript block in my xslt file and I am at my wit's end.
Here is the XSLT (edited for public consumption):
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">
<xsl:output method="html" indent="yes"/>
<xsl:template match="a">
<xsl:variable name="myVar" select="xpath to the node"/>
<script type='text/javascript'>
googletag.cmd.push(function() {
...
googletag.pubads().setTargeting('label', '<xsl:value-of select="$myVar"/>');
googletag.enableServices();
});
</script>
</xsl:template>
</xsl:stylesheet>
If I transform the XML in Oxygen, this code works fine. But when I run it through my servlet, which uses javax.xml.transform.Transformer.transform(Source xmlSource, Result outputTarget) throws TransformerException, I get this:
googletag.pubads().setTargeting('label', ' ');
Can anyone suggest a possible reason for this discrepancy between Oxygen and my servlet?

Answer 1

Try this instead as contents of your variable:
<xsl:variable name="myVar" select="'xpath to the node'"/>
This ensures the contents is seen as a literal string. Possibly Oxygen is forgiving enough to ignore it and your Java is (correctly) not -- it's an error, because inside the quoted string you should put an expression.
The outer double quotes do not take part in forming the expression, only what's inside. That way you can express either the string '1+2' or the sum 1+2 in a variable.