With Jolt json transformation, is it possible to copy a value into two different attributes?

Question

Am trying something very simple with Jolt transformation but struggling to get it to work.

If I have an input like:

{
  "id": "54436001"
}

I want output to be:

{
  "mediaId" : "54436001",
  "events" : {
    "mediaId" : "54436001"
  }
}

Which is copying a value to two different attributes. I would be tempted to try spec like this to work, but obviously it doesn't because of duplicate key.

[
  {
    "operation": "shift",
    "spec": {
      "id": "mediaId",
      "id": "events.mediaId"
    }
  }
]

Is this possible with Jolt transformation ?

Sherbet

Answer 1

Yes

Spec

[
  {
    "operation": "shift",
    "spec": {
      "id": ["mediaId", "events.mediaId"]
    }
  }
]

The idea is if you want shift to write a value to two locations in the output, use an array on the right hand side of the spec.

Brashear

Is there any good jolt transformation tutorial you know? Most of the tutorial I found seems bit complex for a quick read. I using it along with Apache Nifi, which comes very handy, but am using a very light form of it. – Sherbet

Answer 2

Yet, there are some other alternatives such as

[
  {
    "operation": "shift",
    "spec": {
      "id": "mediaId",
      "@id": "events.mediaId"
    }
  }
]

[
  {
    "operation": "shift",
    "spec": {
      "id": "events.mediaId",
      "@0,id": "mediaId"
    }
  }
]

[
  {
    "operation": "shift",
    "spec": {
      "*": {
        "@": "mediaId",
        "@0": "events.mediaId"
      }
    }
  }
]

[
  {
    "operation": "shift",
    "spec": {
      "*": {
        "*": {
          "$": "mediaId",
          "@1": "events.mediaId"
        }
      }
    }
  }
]

all of them will return the same desired result

Rota