Wsrtjtyk

I'm trying to create a flow, that takes the URI params it got called with and uses them to call another flow (the number of times the other flow is called depends on the number of URI params).

    <flow name="get:/test-config">



    <set-variable value="#[message.inboundProperties['http.query.params']]" variableName="params" doc:name="Variable"/>



    <!-- Iterate over the keys to retrieve each params list -->

    <foreach collection="#[flowVars['params'].keySet()]" doc:name="For Each">



        <!-- Iterate over the params list for each key -->

        <foreach collection="#[params.getAll(payload)]" doc:name="For Each">



            <logger level="WARN" message="Parameter - key: #[rootMessage], value: #[payload]" doc:name="Logger"/>



            <set-variable variableName=„Id“ value="#[payload]" doc:name="Variable"/>



            <logger message="Id: #[payload]" level="INFO" doc:name="Logger"/>



            <http:request config-ref="HTTP_REQUEST" path=„/test1/foo“ method="GET" doc:name="HTTP">

                <http:request-builder>

                    <http:query-param paramName=„Id" value="#[flowVars.Id]"/>

                </http:request-builder>

            </http:request>



            <dw:transform-message doc:name="Transform Message">

                <dw:set-payload><![CDATA[%dw 1.0

                    %output application/json

                    ---

                    {

                        "Id" : flowVars.Id,

                        "color" : payload.*color

                    } ]]>

                </dw:set-payload>

             </dw:transform-message>



             <logger message="#[payload]" level="INFO" doc:name="Logger"/>



         </foreach>



    </foreach>



    </flow>

The flow that gets called via the HTTP Request delivers data in JSON format:

   "Id": "1",

       "color": [

           "blue",

           "green"

       ]



   "Id": "2",

       "color": [

           "yellow",

           "blue"

       ]



   "Id": "3"

   ...



   "Id" : "4"

   ...

 
I'd like to filter and aggregate these outputs so the overall result looks like this:

     "Ids": [

         "1",

         "2"

      ]

      "commonColor": [

           "blue"

      ]

And at this point I'm kinda stuck as the number of data sets to merge varies and I also don't quite know how to access and compare the fields of the payload to find items with matching colors, as the payload changes with every iteration. One idea I came across was to save / append the current payload in a variable to save it for further processing, but all examples just worked with 2 or a maximum of three payloads, whereas I'm confronted with an arbitrary amount of possible payloads (and the position / number of colors also varies...).

Any ideas / help on how this problem could be solved would be very appreciated!

PS: I also came across Scatter / Gather, but I'm not quite sure if it's suitable in this case, as I don't know the number of calls / intermediary results beforehand...