Error while invoking wso2 data service from wso2 esb sequence - wso2-esb

Question

I am trying to get some data from wso2 data service via wso2 esb sequence as below
<sequence xmlns="http://ws.apache.org/ns/synapse" name="ConcurGetSAEExtractFlow">
<log level="custom">
<property name="Debugging" value="ConcurGetSAEExtractFlow" />
</log>
<xslt key="GetConcurSAE_Extract_Transformation" />
<property name="post-data-service-sequence" value="ConcurTransformSAEExtractFlow" />
<property name="OUT_ONLY" value="false" />
<send receive="DataServiceInvocationErrorFlow">
<endpoint key="ConcurDataServiceEndpoint" />
</send>
<description />
</sequence>
The xslt transformation GetConcurSAE_Extract_Transformation is as below
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:dat="http://ws.wso2.org/dataservice" xmlns:fn="http://www.w3.org/2005/02/xpath-functions" version="1.0">
<xsl:template match="/">
<xsl:element name="dat:GetConcurSAEExtract">
</xsl:element>
</xsl:template>
</xsl:stylesheet>
As seen there is no input mappings for the service and output mappings are provided. I have already tested the service in the wso2 dss "try this service" and it runs well.
But whereas when I am trying to run this through the wso2 esb through a proxy I receive the below error block
TID: [] [WSO2 ESB] [2013-01-25 01:26:24,244] INFO {org.apache.synapse.mediators.builtin.LogMediator} - Debugging = ConcurGetSAEExtractFlow {org.apache.synapse.mediators.builtin.LogMediator}
TID: [] [WSO2 ESB] [2013-01-25 01:26:24,252] WARN {org.apache.synapse.transport.nhttp.ClientHandler} - Received an internal server error : Internal Server Error For : 10.12.46.5:9764 For Request : Axis2Request [Message ID : urn:uuid:2b34a4c3-796e-410b-aa62-47f28f88f8b7] [Status Completed : true] [Status SendingCompleted : true] {org.apache.synapse.transport.nhttp.ClientHandler}
TID: [] [WSO2 ESB] [2013-01-25 01:26:24,253] INFO {org.apache.axis2.builder.BuilderUtil} - OMException in getSOAPBuilder {org.apache.axis2.builder.BuilderUtil}
org.apache.axiom.soap.SOAPProcessingException: First Element must contain the local name, Envelope , but found html
at org.apache.axiom.soap.impl.builder.StAXSOAPModelBuilder.constructNode(StAXSOAPModelBuilder.java:305)
at org.apache.axiom.soap.impl.builder.StAXSOAPModelBuilder.createOMElement(StAXSOAPModelBuilder.java:252)
at org.apache.axiom.soap.impl.builder.StAXSOAPModelBuilder.createNextOMElement(StAXSOAPModelBuilder.java:234)
at org.apache.axiom.om.impl.builder.StAXOMBuilder.next(StAXOMBuilder.java:249)
at org.apache.axiom.soap.impl.builder.StAXSOAPModelBuilder.getSOAPEnvelope(StAXSOAPModelBuilder.java:204)
at org.apache.axiom.soap.impl.builder.StAXSOAPModelBuilder.<init>(StAXSOAPModelBuilder.java:154)
at org.apache.axiom.soap.impl.builder.StAXSOAPModelBuilder.<init>(StAXSOAPModelBuilder.java:140)
at org.apache.axis2.builder.BuilderUtil.getSOAPBuilder(BuilderUtil.java:728)
at org.apache.axis2.transport.TransportUtils.createDocumentElement(TransportUtils.java:197)
at org.apache.axis2.transport.TransportUtils.createSOAPMessage(TransportUtils.java:145)
at org.apache.synapse.transport.nhttp.ClientWorker.run(ClientWorker.java:223)
at org.apache.axis2.transport.base.threads.NativeWorkerPool$1.run(NativeWorkerPool.java:172)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:662)
TID: [] [WSO2 ESB] [2013-01-25 01:26:24,254] INFO {org.apache.axis2.builder.BuilderUtil} - Remaining input stream :[] {org.apache.axis2.builder.BuilderUtil}
TID: [] [WSO2 ESB] [2013-01-25 01:26:24,254] WARN {org.apache.synapse.transport.nhttp.ClientWorker} - Unexpected response received. HTTP response code : 500 HTTP status : Internal Server Error exception : First Element must contain the local name, Envelope , but found html {org.apache.synapse.transport.nhttp.ClientWorker}
TID: [] [WSO2 ESB] [2013-01-25 01:26:24,273] INFO {org.apache.synapse.mediators.builtin.LogMediator} - status = success response from DSS {org.apache.synapse.mediators.builtin.LogMediator}
I am not able to find out what's going wrong which results in this kind of error.Please if anybody have an idea on this.

Answer 1

You're not copying the soap envelope and header with your XSLT. Make once a <log level="full"/> before and after your <xslt> call, then you'll see that your XSLT will also get a <soap:envelope><soap:body>...
So you'll have to put that in the output as well.
Pseudo code:
<xsl:template match="envelope|body">
<xsl:copy>
<xsl:apply-templates/>
</xsl:copy/>
</xsl:template>