Mule Dev Tricks: DataWeave Using mapObject - Part II

Introduction

In the last part DataWeave Using mapObject - Part I. I presented a way to add new attribute to the payload. In this post, I am going to demonstrate the dataweave code for change keys of the JSON payload.

Input Data

[
  {
    "worker_id": "AMAGWK00002673",
    "position_id": "35119973",
    "requisition_id": "R-32353",
    "applicant_id": "199505",
    "staff_id": "199504"
  },
  {
    "worker_id": "AMAGWK00002674",
    "position_id": "35119943",
    "requisition_id": "R-32353",
    "applicant_id": "199505",
    "staff_id": "199506"
  },
  {
    "worker_id": "AMAGWK00002675",
    "position_id": "35119975",
    "requisition_id": "R-32354",
    "applicant_id": "199507",
    "staff_id": ""
  }
]

Desired Result

[
  {
    "ew_id": "AMAGWK00002673",
    "position_id": "35119973",
    "requisition_id": "R-32353",
    "applicant_id": "199505",
    "staff_id": "199504",
    "type": "re-hire"
  },
  {
    "ew_id": "AMAGWK00002674",
    "position_id": "35119943",
    "requisition_id": "R-32353",
    "applicant_id": "199505",
    "staff_id": "199506",
    "type": "re-hire"
  },
  {
    "ew_id": "AMAGWK00002675",
    "position_id": "35119975",
    "requisition_id": "R-32354",
    "applicant_id": "199507",
    "staff_id": "",
    "type": "new-hire"
  }
]

Solution

%dw 1.0
%output application/json
---
payload map ((worker) ->{
 (worker mapObject (value, key) -> {
  (ew_id : value) when key as :string == 'worker_id', 
  ((key) : value) when (key as :string != 'worker_id')
 }),
 type : "new-hire" when worker.staff_id == null or worker.staff_id == '' otherwise 're-hire'
})

Key learning Points

From the solution I provided, the key syntax is that if the key is worker_id, we will update the key with new key value which is ew_id.

  (ew_id : value) when key as :string == 'worker_id', 
  ((key) : value) when (key as :string != 'worker_id')