set a context for relative XPath-expressions

d2t_nk · March 8th, 2011, 04:19 PM

Hi,
to generate XSLT-Stylesheets i need a generic solution to set a context for relative XPath-expressions (or not relative). I've used:

Code:

<xsl:variable name="context" select="//context"/>
<xsl:value-of select="$context/(relativeXPath)"/>

Almost every time it works very fine. But now i have a problem, if the relativeXPath includes some for-loops. For example:
XML:

Code:

<context>
	<node a="1"/>
	<node a="2"/>
</context>
<difContext/>

both templates below should do the same thing, but they don't.
this (not "generic" variant) works, like it should:

Code:

<xsl:template match="context">
	<xsl:copy-of select="for $i in 0 to 1 return node[@a>$i]"/>
</xsl:template>

it returns:

Code:

<node a="1"/><node a="2"/><node a="2"/>

But this "generic" variant copies just both <node>-elements:

Code:

<xsl:template match="difContext">
	<xsl:variable name="context" select="//context"/>
	<xsl:copy-of select="$context/(for $i in 0 to 1 return node[@a>$i])"/>
</xsl:template>

output:

Code:

<node a="1"/><node a="2"/>

i dont understand why!? is there a reason for this difference? is there a workaround?
(i use oXygen 12.0 with Saxon-PE 9.2.1.2 on Win 7)
thanks for help!

mhkay · March 8th, 2011, 08:22 PM

The "/" operator causes nodes to be sorted into document order with duplicates eliminated. It does more than just setting the context for evaluation of the rhs. You might be better off using xsl:for-each to do that.