authorizeHealthKit.swift

func authorizeHealthKit(completion: @escaping ((_ success: Bool, _ error: MWError?) -> Void)) {
  // If the store is not available (for instance, iPad) return an error and don't go on.
  if !HKHealthStore.isHealthDataAvailable() {
    completion(false, MWError.custom(title: "HealthKit is not available in this Device"))
    return;
  }
  
  // Request HealthKit authorization
  healthKitStore.requestAuthorization(toShare: nil, read: getHealthTypesToRead()) { (success, error) in
    DispatchQueue.main.async { // I'm executing this on mainthread because sometimes 'authorizeHealthKit' called on background thread and I need the completion block on main thread as the destination classes have some UI operations.
      completion(success, error == nil ? nil : MWError.custom(default: error)) // On this completion block on the other classes, I will start fetching the HealthKit data.
    }
  }
}