Difficulty formulating conditions for XSL choose or if - xslt

Question

I am trying to use XSL choose condition. here I am trying to acheive is, when client sends below xml to Dp System. My XSLT should look for values matching Pv(a) or Pv(b) or Pv(c), if any of these are mactched then send to the backend url which is mentioned in the xsl
else
invoke another rule which is called "Do not call rule" (which is nothing but, picks the local file called error.xml
Thanks for the help
Input xml
<DownloadProfileChannels>
<DownloadProfileChannel>
<IntervalLength>60</IntervalLength>
<PulseMultiplier>0.025</PulseMultiplier>
<Category>Pv(a)</Category> <!-- for every Pv(a) or Pv(b) or Pv(c) -->
<TimeDataEnd>2014-02-20T08:00:00Z</TimeDataEnd>
<MedianValues>
<MedianValue>
<ChannelValue>9112</ChannelValue>
<ProfileStatuses i:nil="true" />
</MedianValue>
<MedianValue>
<ChannelValue>9096</ChannelValue>
<ProfileStatuses i:nil="true" />
</MedianValue>
<MedianValue>
<ChannelValue>9188</ChannelValue>
<ProfileStatuses i:nil="true" />
</MedianValue>
</MedianValue>
</MedianValues>
</DownloadProfileChannel>
</DownloadProfileChannels>
My XSL
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:dp="http://www.w3.org/1999/XSL/Format">
<xsl:template match="/">
<xsl:message dp:priority="debug"> Entered the XSL File </xsl:message>
</xsl:message>
<xsl:choose>
<xsl:when test="contains($Quantity,'Pv(a) or Pv(b)')">
<xsl:variable name="destURL"
select="http://backendurl.com"/>
<dp:set-variable name="'var://service/routing-url'"
value="$destURL"/>
</xsl:when>
<xsl:otherwise>
<xsl:variable name="destURL"
select="local:///clienterror.xml"/>
</xsl:otherwise>
</xsl:choose>
</xsl:template>
</xsl:stylesheet>

Answer 1

This line:
<xsl:when test="contains($Quantity,'Pv(a) or Pv(b)')">
Is checking if $Quantity contains the literal string 'Pv(a) or Pv(b)'. You need to separate these out into two check like so:
<xsl:when test="contains($Quantity,'Pv(a)') or contains($Quantity,'Pv(b)')">

Answer 2

Firstly, as #Lego Stormtroopr says, you need to separate out the two conditions. But also, I don't think you really want a "contains" test here, you want an "=" test. The contains function would match Pv(a)(b)(c) - anything that has Pv(a) as a substring, whereas I think you want to match the whole node. So it becomes
<xsl:when test="$Quantity = 'Pv(a)' or $Quantity ='Pv(b)'">
which, if you are using XSLT 2.0, can be further abbreviated to
<xsl:when test="$Quantity = ('Pv(a)', 'Pv(b)')">
Alternatively, in XSLT 2.0 you can use regular expression matching:
<xsl:when test="matches($Quantity, 'Pv([ab])')">