Mule 4: Dataweave 2 In Action - Using Filter

Use Cases

The requirement is to update overall status to PARTIAL if there is any failure record in the payload, i. e. item.status = "Failed"

Input:

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{     "status": "SUCCESS",     "items": [         {             "accountId": "10101xyzabc",             "status": "Success"         },         {             "accountId": "10102aaabbb",             "status": "Failed"         }     ] }

Expected Output:

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{     "status": "PARTIAL",     "items": [         {             "accountId": "10101xyzabc",             "status": "Success"         },         {             "accountId": "10102aaabbb",             "status": "Failed"         }     ] }

Datawave 2.0

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%dw 2.0 output application/json --- {  status: if (sizeOf(payload.items map($) filter ($.status == "Failed")) > 0) "PARTIAL" else "SUCCESS",  items: payload.items }

Complete Flow

The following is the complete flow. Please note that I have commented out the transformation payload to java. This is a big improvement of Mule 4 over mule 3.

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<flow name="use-filterFlow" doc:id="ddae1e7c-0e9c-424c-842a-5ac4ae018b21">   <http:listener doc:name="Listener" doc:id="f0a9f441-4585-4e81-969a-a2d10ad480d1" config-ref="HTTP_Listener_config" path="/mule4/poc/filter">    <ee:repeatable-file-store-stream>   </ee:repeatable-file-store-stream></http:listener> <!--     <ee:transform doc:name="Transform Message" doc:id="f471f35a-3050-43d8-99fe-dfd1fbb07292" >    <ee:message >     <ee:set-payload resource="dataweave/toJava.dwl" />    </ee:message>   </ee:transform>  -->    <ee:transform doc:name="Transform Message" doc:id="c9ef1500-033f-48f6-92f0-a760c75188d3">    <ee:message>     <ee:set-payload resource="dataweave/useFilter.dwl">    </ee:set-payload></ee:message>    <ee:variables>    </ee:variables>   </ee:transform>   <logger level="INFO" doc:name="Logger" doc:id="9958ba07-b13b-4bea-82ea-a28696437345" message="#[payload]">  </logger></flow>

Key Learnings

1. sizeOf function
2. filter function
3. if else, in Dataweave 1.0, this will be when else

if else is a very good syntax improvement over Dataweave 1.0