Heart Rate data on apple Watch

Question

Can we access the heart rate directly from the apple watch? I know this is a duplicate question, but no one has asked this in like 5 months. I know you can access it from th

Answer 1

You can get heart rate data by starting a workout and query heart rate data from healthkit.

1. Ask for premission for reading workout data.

   HKHealthStore *healthStore = [[HKHealthStore alloc] init];
   HKQuantityType *type = [HKQuantityType quantityTypeForIdentifier:HKQuantityTypeIdentifierHeartRate];
   HKQuantityType *type2 = [HKQuantityType quantityTypeForIdentifier:HKQuantityTypeIdentifierDistanceWalkingRunning];
   HKQuantityType *type3 = [HKQuantityType quantityTypeForIdentifier:HKQuantityTypeIdentifierActiveEnergyBurned];
   
   [healthStore requestAuthorizationToShareTypes:nil readTypes:[NSSet setWithObjects:type, type2, type3, nil] completion:^(BOOL success, NSError * _Nullable error) {
   
   if (success) {
       NSLog(@"health data request success");
   
   }else{
       NSLog(@"error %@", error);
   }
   }];
   

2. In AppDelegate on iPhone, respond this this request

   -(void)applicationShouldRequestHealthAuthorization:(UIApplication *)application{
   
   [healthStore handleAuthorizationForExtensionWithCompletion:^(BOOL success, NSError * _Nullable error) {
           if (success) {
               NSLog(@"phone recieved health kit request");
           }
       }];
   }
   

3. Then implement Healthkit Delegate:

   -(void)workoutSession:(HKWorkoutSession *)workoutSession didFailWithError:(NSError *)error{
   
   NSLog(@"session error %@", error);
   }
   
   -(void)workoutSession:(HKWorkoutSession *)workoutSession didChangeToState:(HKWorkoutSessionState)toState fromState:(HKWorkoutSessionState)fromState date:(NSDate *)date{
   
   dispatch_async(dispatch_get_main_queue(), ^{
       switch (toState) {
           case HKWorkoutSessionStateRunning:
   
               //When workout state is running, we will excute updateHeartbeat
               [self updateHeartbeat:date];
               NSLog(@"started workout");
           break;
   
           default:
           break;
       }
       });
   }
   

4. Now it's time to write **[self updateHeartbeat:date]**

   -(void)updateHeartbeat:(NSDate *)startDate{
   
       //first, create a predicate and set the endDate and option to nil/none 
       NSPredicate *Predicate = [HKQuery predicateForSamplesWithStartDate:startDate endDate:nil options:HKQueryOptionNone];
   
       //Then we create a sample type which is HKQuantityTypeIdentifierHeartRate
       HKSampleType *object = [HKSampleType quantityTypeForIdentifier:HKQuantityTypeIdentifierHeartRate];
   
       //ok, now, create a HKAnchoredObjectQuery with all the mess that we just created.
       heartQuery = [[HKAnchoredObjectQuery alloc] initWithType:object predicate:Predicate anchor:0 limit:0 resultsHandler:^(HKAnchoredObjectQuery *query, NSArray *sampleObjects, NSArray *deletedObjects, HKQueryAnchor *newAnchor, NSError *error) {
   
       if (!error && sampleObjects.count > 0) {
           HKQuantitySample *sample = (HKQuantitySample *)[sampleObjects objectAtIndex:0];
           HKQuantity *quantity = sample.quantity;
           NSLog(@"%f", [quantity doubleValueForUnit:[HKUnit unitFromString:@"count/min"]]);
       }else{
           NSLog(@"query %@", error);
       }
   
       }];
   
       //wait, it's not over yet, this is the update handler
       [heartQuery setUpdateHandler:^(HKAnchoredObjectQuery *query, NSArray *SampleArray, NSArray *deletedObjects, HKQueryAnchor *Anchor, NSError *error) {
   
        if (!error && SampleArray.count > 0) {
           HKQuantitySample *sample = (HKQuantitySample *)[SampleArray objectAtIndex:0];
           HKQuantity *quantity = sample.quantity;
           NSLog(@"%f", [quantity doubleValueForUnit:[HKUnit unitFromString:@"count/min"]]);
        }else{
           NSLog(@"query %@", error);
        }
   }];
   
       //now excute query and wait for the result showing up in the log. Yeah!
       [healthStore executeQuery:heartQuery];
   }
   

You also have a turn on Healthkit in capbilities. Leave a comment below if you have any questions.