Getting error "XPath is invalid" for "hours-from-duration($duration)" - xslt

Question

I need help with one of my issues. I am new to XSLT. Right now I am trying to write an XSLT which will generate text output (example: "01:30").
In my XSLT 2.0, I am calling the XPath function hours-from-duration($duration) and this function is throwing the error
XPath is invalid
I can also see the above error in the following logs. Please help me with my issues. Thanks...
16:01:39,403 ERROR [main] JAXPSAXProcessorInvoker - Error checking type of the expression 'funcall(hours-from-duration, [variable-ref(duration/node-set)])'.
16:01:39,404 ERROR [main] JAXPSAXProcessorInvoker - Could not compile stylesheet
javax.xml.transform.TransformerConfigurationException: Could not compile stylesheet at com.sun.org.apache.xalan.internal.xsltc.trax.TransformerFactoryImpl.newTemplates(TransformerFactoryImpl.java:858) at com.sun.org.apache.xalan.internal.xsltc.trax.TransformerFactoryImpl.newTransformer(TransformerFactoryImpl.java:648)
My XSLT:
<?xml version="1.0"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:date="http://exslt.org/dates-and-times"
xmlns:str="http://exslt.org/strings"
xmlns:fn="http://www.w3.org/2005/xpath-functions"
version="1.0" xmlns:xalan="http://xml.apache.org/xslt">
<xsl:output method="text" />
<xsl:variable name="request" select="/*[local-name()='Payout']/*[local-name()='Request']" />
<xsl:variable name="duration" select="$request/Time" />
<xsl:template match="/">
<xsl:value-of select="(hours-from-duration($duration))"/>
<xsl:text>:</xsl:text>
<xsl:value-of select="(minutes-from-duration($duration))"/>
</xsl:template>
</xsl:stylesheet>
XML Input:
<Payout>
<Request Commit="true" Transaction="false">
<Month>JAN</Month>
<Time>P01H30M33S</Time>
</Request>
</Payout>

Answer 1

Your duration value is invalid. It is missing a "T". It should be PT01H30M33S.

Answer 2

hours-from-duration() is an XPath 2.0 function. You are using Xalan, which only supports XSLT 1.0 and XPath 1.0.
Furthermore, these functions expect an object of type xs:duration. You are passing it a node (a Time element). If you switch to an XSLT 2.0 processor, you will need either (a) to make sure the processor is schema-aware and Time is validated as an xs:duration, or (b) to convert it to type xs:duration explicitly, by calling xs:duration(Time).
And of course you will need to make sure it's a valid duration as pointed out by #MadsHansen