Using substring in xsl - xslt

Question

Following on from an earlier question, and this is more about xsl syntax. I want to split part of a URL variable into a new variable in xsl.
This code works when the variable is sitting part way along a URL. EG:
http://www.mysite.com/test.aspx?aVar=something&bVar=somethingMore&cVar=yetMoreStill
<xsl:variable name="testVar" select="substring-after($url, 'bVar=')"/>
<xsl:value-of select="substring-before($testVar, '&')" />
The problem is the variable can sometime sit at the end of the URL (I have no control over this) EG:
http://www.mysite.com/test.aspx?aVar=something&bVar=somethingMore
So the above code fails. Is there away I can allow for both occurrences? The end game is I'm just trying to get the value of bVar no matter where it sits within the URL. Thanks.

Answer 1

How about the following workaround?
<xsl:variable name="testVar" select="substring-after($url, 'bVar=')"/>
<xsl:value-of select="substring-before(concat($testVar, '&'), '&')" />

Answer 2

Try this. This is XSLT 1.0:
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:fo="http://www.w3.org/1999/XSL/Format" xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xsl:template match="/">
<xsl:call-template name="urlResolver">
<xsl:with-param name="input" select="'http://www.mysite.com/test.aspx?aVar=something&bVar=somethingMore'" />
</xsl:call-template>
<xsl:call-template name="urlResolver">
<xsl:with-param name="input" select="'http://www.mysite.com/test.aspx?aVar=something&bVar=somethingMore&cVar=yetMoreStill'" />
</xsl:call-template>
</xsl:template>
<xsl:template name="urlResolver">
<xsl:param name="input" />
<xsl:variable name="testVar" select="substring-after($input, 'bVar=')"/>
<xsl:choose>
<xsl:when test="contains($testVar, '&')"><xsl:value-of select="substring-before($testVar, '&')" /></xsl:when>
<xsl:otherwise><xsl:value-of select="$testVar" /></xsl:otherwise>
</xsl:choose>
</xsl:template>
</xsl:stylesheet>

Answer 3

Try to make use of tokenize (available in XSLT 2.0) like the following:
<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output indent="yes" omit-xml-declaration="yes" method="xml" version="1.0"/>
<xsl:template match="/">
<xsl:variable name="test"><![CDATA[http://www.mysite.com/test.aspx?aVar=something&bVar=somethingMore&cVar=yetMoreStill]]></xsl:variable>
<xsl:variable name="splitURL" select="tokenize($test,'&')"/>
<xsl:variable name="bvar" select="$splitURL[starts-with(.,'bVar')]"/>
<out><xsl:value-of select="substring-after($bvar, 'bVar=')"/></out>
</xsl:template>
</xsl:stylesheet>

Answer 4

The currently accepted answer is generally wrong.
Try it with this URL:
http://www.mysite.com/test.aspx?subVar=something&bVar=somethingMore
and you get the wrong result: something
This question was already answered... In case you read the answer you would just reuse it and get your QString from the produced result:
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:ext="http://exslt.org/common" exclude-result-prefixes="ext">
<xsl:output omit-xml-declaration="yes" indent="yes"/>
<xsl:strip-space elements="*"/>
<xsl:param name="pUrl" select=
"'http://www.mysite.com/test.aspx?subVar=something&bVar=somethingMore'"/>
<xsl:template match="/">
<xsl:variable name="vrtfQStrings">
<xsl:call-template name="GetQueryStringParams"/>
</xsl:variable>
bVar = "<xsl:value-of select="ext:node-set($vrtfQStrings)/bVar"/>"
</xsl:template>
<xsl:template name="GetQueryStringParams">
<xsl:param name="pUrl" select="$pUrl"/>
<xsl:variable name="vQueryPart" select=
"substring-before(substring-after(concat($pUrl,'?'),
'?'),
'?')"/>
<xsl:variable name="vHeadVar" select=
"substring-before(concat($vQueryPart,'&'), '&')"/>
<xsl:element name="{substring-before($vHeadVar, '=')}">
<xsl:value-of select="substring-after($vHeadVar, '=')"/>
</xsl:element>
<xsl:variable name="vRest" select="substring-after($vQueryPart, '&')"/>
<xsl:if test="string-length($vRest) > 0">
<xsl:call-template name="GetQueryStringParams">
<xsl:with-param name="pUrl" select=
"concat('?', substring(substring-after($vQueryPart, $vHeadVar), 2))"/>
</xsl:call-template>
</xsl:if>
</xsl:template>
</xsl:stylesheet>
When applied on any XML document (not used), this transformation produces the wanted, correct result:
bVar = "somethingMore"