How to recursively parse a single Json field that is defined multiple times, in Play Json

Question

Take the following JSON string as an example:

val document = """{
    "id": "12345",
    "createdTime": "13332517",
    "data": {
        "status": "active",
        "createdTime": "13345178"
    }"""

The field createdTime is defined twice in the document. To return the createdTime at the top layer is done by:

val createdTime = Json.parse(document \ "createdTime")

Take the following JSON string; it is the same as the first example, but it is now an array:

val document1 = """[{
    "id": "12345",
    "createdTime": "13332517",
    "data": {
        "status": "active",
        "createdTime": "13345178"
    }
}, {
    "id": "67890",
    "createdTime": "13332565",
    "data": {
        "status": "active",
        "createdTime": "13345173"
    }
}]"""

To recursively return "createdTime" is defined as:

val createdTime1 = Json.parse(document1) \\ "createdTime"

However this also returns the nested createdTime fields. Is there a way to recursively return only the top layer createdTime?

Answer 1

When you parse the document1 and cast it to JsArray, you should have an array. Then you can iterate on the value with map to get the top layer createdTime's.

val createdTimes = Json.parse(document1).as[JsArray].value.map(_ \ "createdTime")