correlationQuery static method

Future<List<Correlation>> correlationQuery(String identifier, Predicate predicate, { Map<String, Predicate>? typePredicates, })

Returns Correlation samples for the provided identifier, the time interval predicate predicate and optional typePredicates for Category and/or Quantity values.

Warning: In order to use the correlations, you must be sure, that you have provided reading permissions for relevant QuantityType.

For instance, if you want to get the data for CorrelationType.bloodPressure, you need to ask user to give read permissions for QuantityType.bloodPressureDiastolic and QuantityType.bloodPressureSystolic. Otherwise HealthKit will throw fatal error with message: "Authorization to read the following types is disallowed: HKCorrelationTypeIdentifierBloodPressure".

Implementation

static Future<List<Correlation>> correlationQuery(
    String identifier, Predicate predicate,
    {Map<String, Predicate>? typePredicates}) async {
  final arguments = {
    'identifier': identifier,
    'typePredicates': typePredicates,
  };
  arguments.addAll(predicate.map);
  final result =
      await _methodChannel.invokeMethod('correlationQuery', arguments);
  final List<dynamic> list = jsonDecode(result);
  final correlations = <Correlation>[];
  for (final Map<String, dynamic> map in list) {
    final correlation = Correlation.fromJson(map);
    correlations.add(correlation);
  }
  return correlations;
}