Jolt Transformation: Make the nested object field to be part of main Json Object and also convert the nested object to String

Question

I am new to JOLT transformation, can someone help me in transforming the Input JSON to the desired output?

Input JSON:

[
  {
    "product_id": 1,
    "product_description": "Product 1 details",
    "billing_details": {
      "product_id": 1,
      "billing_description": "Product 1 billing  Details"
    },
    "product_part_desc": {
      "id": 1,
      "part_description": "product 1 part description"
    }
  },
  {
    "product_id": 2,
    "product_description": "Product 2 details",
    "billing_details": {
      "product_id": 1,
      "billing_description": "Product 2 billing  Details"
    },
    "product_part_desc": {
      "id": 1,
      "part_description": "product 2 part description"
    }
  }
]

Tried Specification:

[
  {
    "operation": "shift",
    "spec": {
      "*": {
        "product_id": "[&1].id",
        "product_description": "[&1].description",
        "billing_details": {
          "billing_description": "[&2].bill_desc"
        },
        "*": "&"
      }
    }
  },
  {
    "operation": "modify-overwrite-beta",
    "spec": {
      "*": {
        "product_part_desc": "=toString(@(1,product_part_desc))"
      }
    }
  }
]

Expected output:

[
  {
    "id": 1,
    "product_description": "Product 1 details",
    "billing_description": "Product 1 billing  Details",
    "product_part_desc": "{id=1, part_description=product 1 part description}"
  },
  {
    "product_id": 2,
    "product_description": "Product 2 details",
    "billing_description": "Product 2 billing  Details",
    "product_part_desc": "{id=1, part_description=product 2 part description}"
  }
]

But the above spec is giving the below output

Answer 1

You can use:

• a concat function within a modify spec in order to get product_part_desc attribute
• a @billing_details.billing_description identifier along with a shift transformation spec to get billing_description attribute

as result:

[
  {
    "operation": "modify-overwrite-beta",
    "spec": {
      "*": {
        "product_part_desc": "=concat('',@0)"
      }
    }
  },
  {
    "operation": "shift",
    "spec": {
      "*": {
        "*id": "[&1].id",
        "p*": "[&1].&",
        "@billing_details.billing_description": "[&1].billing_description"
      }
    }
  },
  {// this spec is added only to sort the attributes as desired
    "operation": "shift",
    "spec": {
      "*": {
        "id": "[&1].&",
        "product_description": "[&1].&",
        "billing_description": "[&1].&",
        "product_part_desc": "[&1].&"
      }
    }
  }
]

Answer 2

You can use this spec:

[
  {
    "operation": "shift",
    "spec": {
      "*": {
        "product_id": "[&1].id",
        "product_description": "[&1].description",
        "billing_details": {
          "billing_description": "[&2].bill_desc"
        },
        "product_part_desc": {
          "*": "[&2].product_part_desc"
        }
      }
    }
  },
  {
    "operation": "modify-overwrite-beta",
    "spec": {
      "*": {
        "product_part_desc": "=join(', part_description=',@0)",
        "product_part_des*": "=concat('{id=',@0,'}')"
      }
    }
  }
]

You can change the keys as you want in the above code.