Filter object in an array and retain other fields in Mule4

Question

I have 2 objects in request payload which needs to be filtered based on a field value in Mule4. Request json:

{
"Fruits": {
 "Types": [
{
 "Field1": "value1",
 "Field2": "value2",
 "Color" : {
  "Types": [
   {
    "Order": "test",
    "Cost": "22"
    },
    {
    "Order": "test1",
    "Cost": ""
    }
    ]
    }
    }
    ]
    },
    "Color" : {
  "Types": [
   {
    "Order": "test",
    "Cost": "22"
    },
    {
    "Order": "test1",
    "Cost": ""
    }
    ]
    }
    } 

In the above payload, all the fields are required but for Color.Types array, we need to filter only the object where cost != null from both Color objects above.

Expected output json:

{
    "Fruits": {
     "Types": [
    {
     "Field1": "value1",
     "Field2": "value2",
     "Color" : {
      "Types": [
       {
        "Order": "test123",
        "Cost": "44"
        }
        ]
        }
        }
        ]
        },
        "Color" : {
      "Types": [
       {
        "Order": "test",
        "Cost": "22"
        }
        ]
        }
        } 

Answer 1

Your Input and Expected Output both are different.

Note -> There is a difference between "" (length is 0) and null (no value allocated)

DW

%dw 2.0
output application/json
import * from dw::util::Values
---
payload update ["Color","Types"] with ($ filter ($.Cost != null and $.Cost != "")) update ["Fruits","Types","Color","Types"] with ($ filter ($.Cost != null and $.Cost != ""))

Output

{
  "Fruits": {
    "Types": [
      {
        "Field1": "value1",
        "Field2": "value2",
        "Color": {
          "Types": [
            {
              "Order": "test",
              "Cost": "22"
            }
          ]
        }
      }
    ]
  },
  "Color": {
    "Types": [
      {
        "Order": "test",
        "Cost": "22"
      }
    ]
  }
}