How to copy a set of nodes stored in a variable in xslt 2.0

Question

I am trying to do something like this:
XSL
<xsl:variable name="setOfNodes" select="foo[@attr = 'bar']" />
<result>
<xsl:copy-of select="$setOfNodes/*" />
</result>XML
<test>
<foo attr="bar" />
<foo attr="bar" />
<foo attr="different" />
<foo attr="bar" />
</test>I want the result to look like this:
<result>
<foo attr="bar" />
<foo attr="bar" />
<foo attr="bar" />
</result>But when I run the above xsl I get:
<result />This seems like it should be pretty simple, I am probably just mixing something up. Does anyone have any ideas or suggestions for how to do this type of thing?

Answer 1

Whether it is XSLT 1.0 or 2.0 does not really matter for your question. As you bind a value to your variable 'setOfNodes' with the XPath expression in the 'select' attribute selecting some 'foo' element nodes the value of that variable is a node-set (in XSLT 1.0) or a sequence (in XSLT 2.0) of those 'foo' element nodes. And if you want to copy those nodes to the result tree then you simply do <xsl:copy-of select="$setOfNodes"/>. Your attempt with select="$setOfNodes/*" would copy the child elements of those 'foo' elements to the result tree, only all those 'foo' elements are empty, they don't have any child nodes at all, thus nothing is copied to the result tree with your xsl:copy-of attempt.