Using XSLT elements for header variables

Google Cloud Apigee
1

I will be performing XSLT transformations. I would like to use elements from the transformed XML to add to the headers. I would like to pull the ServiceHeader/ServiceName and the TrackingInfo/RequestId to accomplish this. The XML follows. I have not be able to figure that out. Any help would be great.

<Service> 
  <ServiceHeader> 
    <ServiceName>GetInfo</ServiceName>
    <Operation>GetCustInfo</Operation> 
  </ServiceHeader> 
  <TrackingInfo>
    <RequestId>1234567890</RequestId> 
    <RequestTs>01/02/2018 01:00:00.000</RequestTs> 
  </TrackingInfo> 
  <RequestInfo> 
    <Name>Any Name</Name> 
  </RequestInfo> 
</Service>
1 Like
2

You said “I would like to pull the ServiceHeader/ServiceName and the TrackingInfo/RequestId”. I think your use of XSLT before or after “pulling” is irrelevant. Correct me if that is mistaken.

To do what you want in Apigee Edge - to extract information from an XML payload - you can use the ExtractVariables policy. For the XML document you have above, it would look something like this:

<ExtractVariables name='EV-1'>
  <Source>contrivedMessage</Source>
  <VariablePrefix>extracted</VariablePrefix>
  <IgnoreUnresolvedVariables>false</IgnoreUnresolvedVariables>
  <XMLPayload>
    <Variable name='svcname' type='string'>
      <XPath>/Service/ServiceHeader/ServiceName/text()</XPath>
    </Variable>
    <Variable name='requestid' type='string'>
      <XPath>/Service/TrackingInfo/RequestId/text()</XPath>
    </Variable>
  </XMLPayload>
</ExtractVariables>

After you extract this data you can use AssignMessage to set headers with those values. Like this:

<AssignMessage name='AM-Response'>
  <Set>
    <Headers>
      <Header name='ServiceName'>{extracted.svcname}</Header>
      <Header name='RequestId'>{extracted.requestid}</Header>
    </Headers>
    <Payload contentType='application/json'>{
    "status" : "ok"
}</Payload>
  </Set>
  <IgnoreUnresolvedVariables>true</IgnoreUnresolvedVariables>
  <AssignTo createNew='false' transport='http' type='response'/>
</AssignMessage>

The result I see (note the response headers) :

$ curl -i [https://${ORG}-${ENV}.apigee.net/extractvariables-1/t1](https://${ORG}-${ENV}.apigee.net/extractvariables-1/t1) 
HTTP/1.1 200 OK
Date: Thu, 29 Mar 2018 00:57:42 GMT
Content-Type: application/json
Content-Length: 23
Connection: keep-alive
ServiceName: GetInfo
RequestId: 1234567890

{
    "status" : "ok"
}

See attached for a working API Proxy.

apiproxy-extractvariables-1-20180328-1804.zip

3

Thank you very much.