unable to combine two responses in xml payload in APIGEE mashup

[#1]

Hi All,

I'm facing issues in trying to combine 2 XML responses into using APIGEE mashup. Below is my configuration:

XML Payload 1:

<root>
<parent>
<fname>A</fname>
</parent>
<parent>
<fname>B</fname>
</parent>
<parent>
<fname>C</fname>
</parent>
</root>

Callout Service 1:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ServiceCallout async="false" continueOnError="false" enabled="true" name="callout_service_1">
    <DisplayName>callout_service_1</DisplayName>
    <Properties/>
    <Request clearPayload="true" variable="myRequest">
        <IgnoreUnresolvedVariables>false</IgnoreUnresolvedVariables>
    </Request>
    <Response>calloutResponse_1</Response>
    <HTTPTargetConnection>
        <Properties/>
        <URL>https://localhost:8080/getService1</URL>
    </HTTPTargetConnection>
</ServiceCallout>

Extract Variables 1:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ExtractVariables async="false" continueOnError="false" enabled="true" name="extract_service_1">
    <DisplayName>extract_service_1</DisplayName>
    <Properties/>
    <Source clearPayload="false">calloutResponse_1</Source>
    <VariablePrefix>detailResponse1</VariablePrefix>
    <XMLPayload stopPayloadProcessing="false">
        <Variable name="parent" type="nodeset">
            <XPath>//root/parent</XPath>
        </Variable>
    </XMLPayload>
</ExtractVariables>

XML Payload 2:

<root>
<parent>
<fname>D</fname>
</parent>
<parent>
<fname>E</fname>
</parent>
<parent>
<fname>F</fname>
</parent>
</root>

Callout Service 2:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ServiceCallout async="false" continueOnError="false" enabled="true" name="callout_service_2">
    <DisplayName>callout_service_2</DisplayName>
    <Properties/>
    <Request clearPayload="true" variable="myRequest">
        <IgnoreUnresolvedVariables>false</IgnoreUnresolvedVariables>
    </Request>
    <Response>calloutResponse_2</Response>
    <HTTPTargetConnection>
        <Properties/>
        <URL>https://localhost:8080/getService2</URL>
    </HTTPTargetConnection>
</ServiceCallout>

Extract Variables 2:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ExtractVariables async="false" continueOnError="false" enabled="true" name="extract_service_2">
    <DisplayName>extract_service_2</DisplayName>
    <Properties/>
    <Source clearPayload="false">calloutResponse_2</Source>
    <VariablePrefix>detailResponse1</VariablePrefix>
    <XMLPayload stopPayloadProcessing="false">
        <Variable name="parent" type="nodeset">
            <XPath>//root/parent</XPath>
        </Variable>
    </XMLPayload>
</ExtractVariables>

I'm trying to achieve the below output:

<root>
<parent>
<fname>A</fname>
</parent>
<parent>
<fname>B</fname>
</parent>
<parent>
<fname>C</fname>
</parent>
<parent>
<fname>D</fname>
</parent>
<parent>
<fname>E</fname>
</parent>
<parent>
<fname>F</fname>
</parent>
</root>

When I hit the URL and trace the request, the value of the variable parent from Extract Variables 1 is getting overridden by Extract Variables 2 as the key is same in both the cases.

I've tried using property <VariablePrefix> but unable to get the response assign to it. I've already raised a ticket on it ref: Facing problem in assigning response from xml payload to variablePrefix.

I tried combining the response using javascript using "+" operator but got an error as below:

This page contains the following errors:
error on line 7 at column 9: Extra content at the end of the document
Below is a rendering of the page up to the first error.

An invalid XML is formed.

Please help me out with this.

[DChiesa]

I've tried using property <VariablePrefix> but unable to get the response assign to it.

Be careful. It could be that the response is being assigned but the Trace does not reflect that. Check your assumption. I believe there is an outstanding bug on this - Trace does not display results of ExtractVariables when there is a VariablePrefix.

Also I noticed your VariablePrefix is the same in both ExtractVariables policies. So that's a problem. if you want to not stomp your variables, use different prefixes, or different names.

Even without the VariablePrefix, you can assign to a different variable name. Why use "parent" in both cases? Why not use "parent2" or anything OTHER than parent in the 2nd ExtractVariables?

    <!-- <VariablePrefix>detailResponse1</VariablePrefix> -->
    <XMLPayload stopPayloadProcessing="false">
        <Variable name="parent2" type="nodeset">
            <XPath>//root/parent</XPath>
        </Variable>
    </XMLPayload> 

But, if your real goal is to mashup 2 xml documents, you don't need ExtractVariables at all. You can use XSL. Here is a question and answer from last week on the topic.

You may be thinking: "XSL!!!?! I don't want XSL!" And I'm sorry about that. But you cannot effectively combine XML with "+" in Javascript. That won't work, without a lot of pain and anguish. XSL is the right tool for the job, here.

[#3]

@Dino: Thank you for your reply. I'll check the reference URL shared by you.