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:

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

Expected Output:

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

Datawave 2.0

%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.

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