How to iterator over a JSON Array in Mule 3 - json

Question

Mule 3.8.3 Studio 6.4.4
I am receiving a XML payload that is a collection of customer numbers. I need to end up pulling each number out and sending it to a messaging queue.
Sample Incoming Data:
<request func="">
<data>
<transactions time='1539262470'>
<transaction set='customers' notifyid='WMS_NADC_CUSTOMERS' type='update'>
<customers>
<customer id="CIT_1113-11" t="1539257721" y="U" w="WebUser"></customer>
<customer id="C42998-2" t="1539261561" y="N" w="WebUser"></customer>
<customer id="C42998" t="1539262040" y="U" w="WebUser"> </customer>
</customers>
</transaction>
</transactions>
</data>
</request>
After receiving this I use weave to transform into json in an attempt to more easily access the id's.
%dw 1.0
%output application/json
---
{
customers: payload.request.data.transactions.transaction.customers.*customer map (cust, indexOfCustomer) ->{
customer: cust.#id as :string
}
}
The transformed payload now looks like
{
"customers": [
{
"customer": "CIT_1113-11"
},
{
"customer": "C42998-2"
},
{
"customer": "C42998"
}
]
}
At this point, I am trying to loop through the payload. Setting the for each to payload.get('customers') takes me into a jackson.node.ArrayNode.
I haven't been able to figure out how to access each individual object inside the list. Can one of you please tell me how to do that?
I want to end up placing a payload onto a message queue that looks like
{
"customer": "C42998"
}

Answer 1

The simplest way would be to use a combination of DataWeave to get a Java Iteratable, and a for-each scope. Check out this example (assuming the incoming payload is your XML).
<dw:transform-message doc:name="Transform Message">
<dw:set-payload><![CDATA[%dw 1.0
%output application/java
%var customers = payload.request.data.transactions.transaction.customers.*customer
---
customers map (customer) ->{
customer: customer.#id as :string
}]]></dw:set-payload>
</dw:transform-message>
<foreach doc:name="For Each">
<json:object-to-json-transformer doc:name="Object to JSON"/>
<logger message="#[payload]" level="INFO" doc:name="Logger"/>
</foreach>
In Mule 3, the for-each won't accept JSON or XML, even if they obviously represent a structure that could be iterated over (like a JSON array, for example). This is why we need %output application/java in the DataWeave transformer. Later, within the for-each scope, we can transform this back to JSON. In your case, just replace the logger with your queue connector to send the messages where needed.