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$spread

$spread(value?) -> value
Compact type signature<x-:a<o>>

If value is omitted, the current context value is used.

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Objects And StructureArrays And Sequences

Source: JSONata

Documentation​

Turns an object into an array of single-key objects.

If the input is an array, $spread() recursively spreads each item and concatenates the results. Non-object scalar values pass through unchanged, so $spread("Hello World") returns the original string rather than wrapping it in an array.

This is useful when you need to transform object members as a sequence before merging or re-projecting them.

Examples​

Turn an object into an array of single-key objects​

Input

This example uses the patient-summary example input. The expression selects the nested identifiers object and spreads it into single-key objects.

Example input

JSON
{
  "patientId": "pat-0001",
  "name": {
    "given": "Avery",
    "family": "Reed",
    "display": "Avery Reed"
  },
  "birthDate": "1990-06-12",
  "sex": "female",
  "primaryCareTeam": {
    "organization": "ExampleCare",
    "facility": "ExampleCare Clinic",
    "practitioner": {
      "practitionerId": "prac-4001",
      "display": "Jordan Kim"
    }
  },
  "identifiers": {
    "memberId": "mbr-3001",
    "recordNumber": "rec-5001"
  },
  "tags": [
    "demo",
    "fictional"
  ],
  "_xmlTagName": "patientSummary"
}

Expression

$spread(identifiers)

Result

[
  { "memberId": "mbr-3001" },
  { "recordNumber": "rec-5001" }
]