How to make HKworkoutsession always an active workout session

Question

I'm working on apple watch app and I'm using HKworkoutsession to access heart rate data sample.

In the newest watchos2 beta3 release bug "During an active workout session, new heart rate samples are not generated when the screen is off." is fixed.

My question is how could I set my HKworkoutsession always as an "active work out session" thus I could keep getting heart rate sample as I need.

Thanks Ryan

Answer 1

Code following is how to start or stop workout session.

let healthStore = HKHealthStore()
healthStore.startWorkoutSession(workoutSession) {
  (result: Bool, error: NSError?) -> Void in
}

healthStore.stopWorkoutSession(workoutSession) {
  (result: Bool, error: NSError?) -> Void in
}

There is HKWorkoutSessionDelegate which notifies its session state.

protocol HKWorkoutSessionDelegate : NSObjectProtocol {

func workoutSession(workoutSession: HKWorkoutSession,
  didChangeToState toState: HKWorkoutSessionState,
  fromState: HKWorkoutSessionState, date: NSDate)

func workoutSession(workoutSession: HKWorkoutSession,
  didFailWithError error: NSError)
}

[Edited] 2015/08/31

ObjC version

HKWorkoutSession *workoutSession = [[HKWorkoutSession alloc] initWithActivityType:HKWorkoutActivityTypeRunning locationType:HKWorkoutSessionLocationTypeOutdoor];
workoutSession.delegate = self;

HKHealthStore *healthStore = [HKHealthStore new];
[healthStore startWorkoutSession:workoutSession];

[healthStore stopWorkoutSession:workoutSession];

HKWrokoutSessionDelegate

- (void)workoutSession:(HKWorkoutSession *)workoutSession
  didChangeToState:(HKWorkoutSessionState)toState
         fromState:(HKWorkoutSessionState)fromState
              date:(NSDate *)date;

- (void)workoutSession:(HKWorkoutSession *)workoutSession didFailWithError:(NSError *)error;

Caution: There is a change of method name with the latest version, watch OS 2 beta 5.

stopWorkoutSession has changed to endWorkoutSession.