XSLT Node availability check - xslt

Question

I want to check a variable have any node or any attribute.
XSL:
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
version="1.0">
<xsl:template match="/">
<xsl:variable name="testvar">
<test><name first="Isaac" last="Sivakumar" middle="G"></name></test>
</xsl:variable>
<xsl:choose>
<xsl:when test="normalize-space($testvar)">
<xsl:value-of select="$testvar"></xsl:value-of>
</xsl:when>
<xsl:otherwise>
<xsl:value-of select="'NO XML DATA AVAILABLE'"></xsl:value-of>
</xsl:otherwise>
</xsl:choose>
</xsl:template>
</xsl:stylesheet>
When I try to run the above code I am getting "NO XML DATA AVIALABLE." I need to check weather a variable has any node / any attributes irrespective of it has data or not.
Can you please help me to fix this.

Answer 1

With XSLT 1.0 your variable has a value of type "result tree fragment", you need to use an extension function to convert it to a node set first to be able to address nodes e.g.
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:exsl="http://exslt.org/common" version="1.0">
<xsl:template match="/">
<xsl:variable name="testvar">
<test><name first="Isaac" last="Sivakumar" middle="G"></name></test>
</xsl:variable>
<xsl:choose>
<xsl:when test="exsl:node-set($testvar)/node()">
<xsl:copy-of select="$testvar"></xsl:value-of>
</xsl:when>
<xsl:otherwise>
<xsl:value-of select="'NO XML DATA AVAILABLE'"></xsl:value-of>
</xsl:otherwise>
</xsl:choose>
</xsl:template>
</xsl:stylesheet>
Using normalize-space or value-of does not make much sense given that your XML in the result tree fragment has all data in attributes and no text nodes with data.
And the test test="exsl:node-set($testvar)/node()" is just an example, it could of course use e.g. test="exsl:node-set($testvar)//name" to test for a specific element like a name element.
Given XSLT 1.0 but EXSLT common support it might be better to check with http://www.exslt.org/exsl/functions/object-type/index.html e.g.
<xsl:choose>
<xsl:when test="exsl:object-type($testvar) = 'string' and $testvar = ''">
<xsl:value-of select="'NO XML DATA AVAILABLE'"/>
</xsl:when>
<xsl:when test="exsl:object-type($testvar) = 'node-set'">
<xsl:copy-of select="$testvar"/>
</xsl:when>
</xsl:choose>
Given XSLT 2.0 I would simply check e.g if ($testvar instance of xs:string and $testvar = '') then 'NO XML DATA AVAILABLE' else $testvar.