Extracting Operation name from SOAP document via XPath in Extract Variables policy

[tsuni_ohsaki]

I have a payload in this format:

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:sch="http://www...com/api/schemas/">
   <soapenv:Header/>
   <soapenv:Body>
      <sch:GetAppointment>

From Apigee policy, I want to assign the method name "GetAppointment". For example I tried these:

        <Variable name="methodname" type="string">
            <XPath>//*[name(/soapenv:Body/*[1])]</XPath>
        </Variable>

        <Variable name="methodname" type="string">
            <XPath>//*[name(/soapenv:Body/*[1])]</XPath>
        </Variable>

I got a compilation error in both cases. I removed "soapenv:", but I could not get the child element name.

What is the XPath value I should use to extract "GetAppointment" in the above example. Or extract "sch:GetAppointment" so that I can parse it and get GetAppointment" eventually?

[dchiesa1]

Usually when people use ExtractVariables on a SOAP document, it's the namespaces that trip them up. The key thing is: you've got to declare your namespaces explicitly in the EV policy. This works for me.

<ExtractVariables name='EV-SOAP-Operation'>
  <Source>request</Source>
  <VariablePrefix>soap</VariablePrefix>
  <IgnoreUnresolvedVariables>false</IgnoreUnresolvedVariables>
  <XMLPayload>
    <Namespaces>
      <Namespace prefix='soap'>http://schemas.xmlsoap.org/soap/envelope/</Namespace>
    </Namespaces>
    <Variable name='topLevelRequestElement' type='string'>
      <XPath>local-name(/soap:Envelope/soap:Body/*[1])</XPath>
    </Variable>
  </XMLPayload>
</ExtractVariables>

Remember: the namespace prefix you use in the XPath expression need not match the namespace prefix used in the document. It's the namespace string that matters; the thing the prefix refers to.  The following is equivalent to the above.

<ExtractVariables name='EV-SOAP-Operation'>
  <Source>request</Source>
  <VariablePrefix>soap</VariablePrefix>
  <IgnoreUnresolvedVariables>false</IgnoreUnresolvedVariables>
  <XMLPayload>
    <Namespaces>
      <Namespace prefix='s'>http://schemas.xmlsoap.org/soap/envelope/</Namespace>
    </Namespaces>
    <Variable name='topLevelRequestElement' type='string'>
      <XPath>local-name(/s:Envelopr/s:Body/*[1])</XPath>
    </Variable>
  </XMLPayload>
</ExtractVariables>

[tsuni_ohsaki · Accepted solution]

It works fine! I became able to assign the entity name. Thanks!