How contruct in xslt a tree in a variable - xslt

Question

I want to create a variable like that :
<xsl:variable name="mytree" >
<foos>
<foo>bar</foo>
<foo>bar</foo>
<foo>bar</foo>
<foo>bar</foo>
<foos>
</xsl:variable>
to use it like in :
<xsl:call-template name="myTemplate">
<xsl:with-param name='aTree' select='$mytree' />
</xsl:call-template>
<xsltemplate name="myTemplate">
<xsl:param name="aTree" />
[My code that treat $aTree like a Tree]
</xsl:template>
My question is : is it possible to create a Tree variable and How?

Answer 1

To achieve this, you probably need to make use of an extension function, namely the node-set function, which returns a set of nodes from a result tree fragment.
First you would need to define the namespace for the extension functions like so
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:msxsl="urn:schemas-microsoft-com:xslt">
In this case, I am using the Microsoft extension functions, but others are available depending on which platform you are using. (http://exslt.org/common is another common one for non-Microsoft platforms).
Then, you can access the elements in your variable like so (as an example)
<xsl:apply-templates select="msxsl:node-set($aTree)/foos/foo"/>
Putting this altogether in a simple example gives you this
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:msxsl="urn:schemas-microsoft-com:xslt" exclude-result-prefixes="msxsl">
<xsl:variable name="mytree">
<foos>
<foo>bar1</foo>
<foo>bar2</foo>
<foo>bar3</foo>
<foo>bar4</foo>
</foos>
</xsl:variable>
<xsl:template match="/">
<xsl:call-template name="myTemplate">
<xsl:with-param name="aTree" select="$mytree"/>
</xsl:call-template>
</xsl:template>
<xsl:template name="myTemplate">
<xsl:param name="aTree"/>
<newfoos>
<xsl:apply-templates select="msxsl:node-set($aTree)/foos/foo"/>
</newfoos>
</xsl:template>
<xsl:template match="foo">
<newfoo>
<xsl:value-of select="text()"/>
</newfoo>
</xsl:template>
</xsl:stylesheet>
When run, this simply outputs the following result:
<newfoos>
<newfoo>bar1</newfoo>
<newfoo>bar2</newfoo>
<newfoo>bar3</newfoo>
<newfoo>bar4</newfoo>
</newfoos>
Given this example, there is no reason why you can't dynamically create your myTree variable first.