Split JSON Array to an Object

Question

I have a payload like below:

{
  "data": [
    {
      "id": "f251f05f-038c-4c26-bf7c-3b2fc47210e6",
      "specialtyIds": [
        "20c5f3f0-54c9-4779-b1a3-19baeee91b4a"
      ]
    },
    {
      "id": "61d34a84-940d-4556-9c4b-ef7bede9caca",
      "specialtyIds": [
        "20c5f3f0-54c9-4779-b1a3-19baeee91b4a",
        "9834e1cf-94c4-4188-83e6-867ac1d60017",
        "30d6g4d3-54c9-4779-b1a3-19baeee92cdc"
      ]
    }
  ]
}

and want to return an array like:

[
  {
    id: "20c5f3f0-54c9-4779-b1a3-19baeee91b4a"
  }, 
  {
    id: "9834e1cf-94c4-4188-83e6-867ac1d60017"
  },
  {
    id: "30d6g4d3-54c9-4779-b1a3-19baeee92cdc"
  }
]

I've used the following dataweave which works fine when specialtyIds is only one element. But the second there's more than one element it breaks:

payload.data map {
    id: $.specialtyIds joinBy(",")
} distinctBy $

if the array has more than two elements the script returns:

[
  {
    id: "20c5f3f0-54c9-4779-b1a3-19baeee91b4a"
  }, 
  {
    id: "20c5f3f0-54c9-4779-b1a3-19baeee91b4a,9834e1cf-94c4-4188-83e6-867ac1d60017"
  }
]

I am relatively new to dataweave, but have explored pluck and reduce to iterate over the arrays but haven't had much luck. I feel like there is probably a simpler way to tackle this structure.

Answer 1

This script gets the last element of each specialityIds arrays and returns the exact output that the question shows as the expected output.

%dw 2.0
output application/json
---
flatten(payload.data.*specialtyIds) map {id: $}