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$sift

$sift(object?, function?) -> object
Compact type signature<o-f?:o>

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

Browse categories
Objects And StructureFunctions That Use Other Functions

Source: JSONata

Documentation​

Filters an object by applying a predicate to each key-value pair and returning a new object with only the matching members.

The callback receives the value, key, and source object. Predicate results are interpreted with JSONata boolean rules. If nothing matches, $sift() returns undefined rather than an empty object.

Use $sift() for object members and $filter() for arrays or sequences.

Examples​

Keep selected object members​

Input

This example uses the patient-summary example input. The expression removes the organization entry from the nested primaryCareTeam object while keeping the other members unchanged.

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

$sift(primaryCareTeam, function($v, $k) { $k != "organization" })

Result

{
  "facility": "ExampleCare Clinic",
  "practitioner": {
    "practitionerId": "prac-4001",
    "display": "Jordan Kim"
  }
}