The str:split function creates a temporary tree, and when you iterate over
the nodes in that tree, "." will refer to a node in that tree, and "/" (and
path expressions beginning with "/") will refer to the root of that tree. If
you want to refer to the root of the principal input document, the remedy is
the same as for any other stylesheet using multiple documents: declare a
global variable
<xsl:variable name="root" select="/"/>
Michael Kay
http://www.saxonica.com/
-----Original Message-----
From: Michael Ludwig [mailto:mlu(_at_)as-guides(_dot_)com]
Sent: 15 February 2008 11:57
To: xsl-list(_at_)lists(_dot_)mulberrytech(_dot_)com
Subject: [xsl] Accessing input document from extension
function loop (XSL 1.0)
This question is related to content generated by extension
functions and the context I'm in when using this content in a
loop. The example requires EXSLT support, particularly
support for the str:split function from "http://exslt.org/strings";.
Here's my input document, "ef.xml":
<Channels>
<Ch ID="ard">ARD</Ch>
<Ch ID="zdf">ZDF</Ch>
</Channels>
Here's my XSL program, "ef.xsl":
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0"
xmlns:php="http://php.net/xsl"; exclude-result-prefixes="php"
xmlns:str="http://exslt.org/strings";
extension-element-prefixes="str"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform";>
<xsl:output method="xml" indent="yes"/>
<xsl:template match="Channels">
<Urmel>
<U1>
<xsl:for-each select="/Channels/Ch/@ID">
<xsl:call-template name="tests"/>
</xsl:for-each>
</U1>
<!-- PHP example <U2>
<xsl:for-each select="php:function('gen_nodes', 'ard zdf')/*">
<xsl:call-template name="tests"/>
</xsl:for-each>
</U2> -->
<U3>
<xsl:for-each select="str:split('ard zdf')">
<xsl:call-template name="tests"/>
</xsl:for-each>
</U3>
</Urmel>
</xsl:template>
<xsl:template name="tests">
<T1><xsl:copy-of select="."/></T1><!-- works as expected -->
<T2><xsl:value-of select="."/></T2><!-- ditto -->
<!-- T3 doesn't work for U2 and U3. -->
<Cur><xsl:value-of select="current()"/></Cur>
<T3><xsl:value-of select="/Channels/Ch[ @ID = current() ]"/></T3>
<!-- Trying to use a variable in T4 doesn't work either. -->
<xsl:variable name="current" select="."/>
<Var><xsl:value-of select="$current"/></Var>
<T4><xsl:value-of select="/Channels/Ch[ @ID = $current ]"/></T4>
</xsl:template>
</xsl:stylesheet>
My command line:
xsltproc ef.xsl ef.xml
What am I trying to do here? I am doing a lookup using a
string value, which is either 'ard' or 'zdf'. Of course, this
lookup is trivial, but triviality here is for the sake of the example.
The interesting part is where I get this string value from.
There are three cases: U1, U2 (requiring PHP, commented out)
and U3 (requiring EXSLT).
In U1, I get the string from the input document itself. No
problem here.
In U2 (commented out) and U3, I get the string from an
extension function, either EXSLT or PHP. And here's the
problem, showing up in T3 and T4. (T1 and T2 work as expected
and are there to show what's going
on.) From inside the xsl:for-each loop using the content
generated by the extension function, I don't seem to be able
to access my original input document. Am I mistaken here or
is this assumption correct?
If it is correct, why is this so?
And is there a remedy? What do I have to do to profit from
extension functions in the way I'm trying to do while
maintaining my ability to access the input document?
For completion's sake, here's the version of libxslt I am using.
libxslt Version => 1.1.20
libxslt compiled against libxml Version => 2.6.27
libexslt Version => 1.1.20
This is XSLT version 1.0, and it has to be: libxslt is 1.0 only.
Optionally, you may comment in the <U2> example and observe
the same thing as in <U3> when processing the stylesheet
using the following PHP program, "ef.php":
<?php
function gen_nodes($str) {
$doc = new DOMDocument;
$root = $doc->appendChild($doc->createElement('Moin'));
foreach (explode(' ', $str) as $s)
$root->appendChild($doc->createElement('Tach'))
->appendChild($doc->createTextNode($s));
return $doc->documentElement;
}
$docstr = <<<EOS
<Channels>
<Ch ID="ard">ARD</Ch>
<Ch ID="zdf">ZDF</Ch>
</Channels>
EOS;
$Xsl = new XSLTProcessor();
$Xsl->registerPHPFunctions();
$Doc = new DOMDocument();
$Doc->loadXML($docstr);
$xsldoc = new DOMDocument();
$xsldoc->load('extension-function.xsl');
$Xsl->importStyleSheet($xsldoc);
echo $Xsl->transformToXML($Doc);
I have asked this question on the very low-traffic EXSLT list
before but the answer hasn't clarified things for me.
[exslt] EXSLT str:split() and evaluation context
http://lists.fourthought.com/pipermail/exslt/2007-September/00
1597.html
http://lists.fourthought.com/pipermail/exslt/2007-October/001600.html
Michael Ludwig
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