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$isEmpty

$isEmpty(value?) -> boolean
Compact type signature<x-:b>

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

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Logical Checks

Source: FUME

Documentation​

Returns true when a value is empty by FUME's recursive rules.

The function treats undefined values, null, empty or whitespace-only strings, empty arrays, empty objects, and arrays or objects whose nested members are all empty as empty. Numbers, booleans, functions, and any structure containing a non-empty nested value return false.

Examples​

Treat a missing field as empty​

Input

This example uses the patient-summary example input. The expression checks a field that is not present in the canonical example data.

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

$isEmpty(name.middle)

Result

true