XSLT 2.0 transformations in BPEL?

Question

I'm using BPEL 10.1.3.1.0, and I want to execute a simple xslt 2.0 stylesheet, that takes two dateTime variables from the inputVariable payload, subtracts them to get a duration, and put this duration back into the outputVariable payload...
Stylesheet:
<xsl:stylesheet version="2.0"
                xmlns:ns1="http://xmlns.oracle.com/durationTest"
                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"
                xmlns:fn="http://www.w3.org/2005/xpath-functions"
                exclude-result-prefixes="xsl ns1 xs fn fo">
  <xsl:template match="/">
    <ns1:durationTestProcessResponse>
      <ns1:result>
        <xsl:value-of select="/ns1:durationTestProcessRequest/ns1:date2 - /ns1:durationTestProcessRequest/ns1:date1"/>
      </ns1:result>
    </ns1:durationTestProcessResponse>
  </xsl:template>
</xsl:stylesheet>This is a snippet from our BPEL process (transform activity):
<assign name="subtractDates">
            <bpelx:annotation>
                <bpelx:pattern>transformation</bpelx:pattern>
            </bpelx:annotation>
            <copy>
                <from expression="ora:processXSLT('Transformation_1.xsl',bpws:getVariableData('inputVariable','payload'))"/>
                <to variable="outputVariable" part="payload"/>
            </copy>
        </assign>My input variable XSD is:
<schema attributeFormDefault="unqualified"
           elementFormDefault="qualified"
           targetNamespace="http://xmlns.oracle.com/durationTest"
           xmlns="http://www.w3.org/2001/XMLSchema">
<element name="durationTestProcessRequest">
     <complexType>
          <sequence>
               <element name="date1" type="dateTime"/>
               <element name="date2" type="dateTime"/>
          </sequence>
     </complexType>
</element>
<element name="durationTestProcessResponse">
     <complexType>
          <sequence>
               <element name="result" type="duration"/>
          </sequence>
     </complexType>
</element>
</schema>This stylesheet works without any problems if I try it in XMLSpy. However, when I execute my BPEL process, the payload of the outputVariable is empty. I do not get any errors... Anyone know why my stylesheet isn't properly executed? If I change the xslt version to 1.0 the result gets filled with 'NaN', which is logical...
TIA,
Bas

Answer 1

For anyone that's interested, I got it to work... The solution was to add dateTime() around the XPath locations to the variables:
<xsl:value-of select="dateTime(/ns1:durationTestProcessRequest/ns1:date2) - dateTime(/ns1:durationTestProcessRequest/ns1:date1)"/>