Azure APIM: XML Transformation Using Multiple XML Responses to Single XML Response

Question

Note: I am using azure apim

I have two api returning xml response show below: Response1:

<A>
  <B>10</B>
</A>

Response2:

<C>
  <D>10</D>
</C>

I want to transform XML response to get the below output , where the Response 2 is put inside the Response 1 Output:

<A>
  <B>10</B>
  <C>
    <D>10</D>
  </C>
</A>

Answer 1

Set inbound policy to achieve it.

My idea is combining using send-request，set-variable and return-response, that's calling 2 APIs first, and save specific value of the request and combine them into a new Xml document. Here's my policy, I used 2 azure function to play the role of API :

   <inbound>
        <base />
        <send-request mode="new" response-variable-name="reqone" timeout="20" ignore-error="true">
            <set-url>https://xxx.azurewebsites.net/api/HttpTrigger1</set-url>
            <set-method>GET</set-method>
        </send-request>
        <send-request mode="new" response-variable-name="reqtwo" timeout="20" ignore-error="true">
            <set-url>https://xxxx.azurewebsites.net/api/HttpTrigger2</set-url>
            <set-method>GET</set-method>
        </send-request>
        <set-variable name="valOne" value="@{
            string text = ((IResponse)context.Variables["reqone"]).Body.As<XDocument>().Root.Value;
            return text;
        }" />
        <set-variable name="valTwo" value="@{
            string text = ((IResponse)context.Variables["reqtwo"]).Body.As<XDocument>().Root.Value;
            return text;
        }" />
        <return-response>
            <set-status code="200" />
            <set-header name="Content-Type" exists-action="override">
                <value>text/xml</value>
            </set-header>
            <set-body>@{
                XDocument srcTree = new XDocument(  
                    new XElement("A",  
                        new XElement("B", context.Variables.GetValueOrDefault("valOne","")),  
                        new XElement("C", new XElement("D", context.Variables.GetValueOrDefault("valTwo","")))
                    )  
                );
                return srcTree.ToString();
            }</set-body>
        </return-response>
    </inbound>

This is my api response:

This is my test result: