Getting updated heart rate data from Health Kit

Question

I wrote this code to get heart rate I am using NSArray and getting average of heart rate. Now the question is the Apple Watch is updating data in Health Kit and I want the updated average heart beats being refreshed at every 1 minutes. I am stuck at this point, please help?

-(double)get_heartRates
{

//code to get the updated heart beats
NSDate *startDate1 = [NSDate distantPast];
NSPredicate *Predicate = [HKQuery predicateForSamplesWithStartDate:startDate1 endDate:[NSDate date] options:HKQueryOptionStrictEndDate];
HKSampleType *object = [HKSampleType quantityTypeForIdentifier:HKQuantityTypeIdentifierHeartRate];

sum_Of_HeartRates=0.0;

HKAnchoredObjectQuery  *heartQuery = [[HKAnchoredObjectQuery alloc] initWithType:object predicate:Predicate anchor:self.lastAnchor limit:0 resultsHandler:^(HKAnchoredObjectQuery *query, NSArray<HKSample *> *sampleObjects, NSArray<HKDeletedObject *> *deletedObjects, HKQueryAnchor *newAnchor, NSError *error) {

    NSLog(@"Sample counts:%ld",sampleObjects.count);
    for(int i=0;i<(int)sampleObjects.count;i++)
    {

        HKQuantitySample *sample = (HKQuantitySample *)[sampleObjects objectAtIndex:i];
        HKQuantity *quantity = sample.quantity;
        double bpm_Values= [quantity doubleValueForUnit:[HKUnit unitFromString:@"count/min"]];
        sum_Of_HeartRates=sum_Of_HeartRates+bpm_Values;

    }
    avg_heartBeats=sum_Of_HeartRates/(int)sampleObjects.count;
}];

[heartQuery setUpdateHandler:^(HKAnchoredObjectQuery *query, NSArray<HKSample *> *SampleArray, NSArray<HKDeletedObject *> *deletedObjects, HKQueryAnchor *Anchor, NSError *error) {

    HKQuantitySample *sample = (HKQuantitySample *)[SampleArray objectAtIndex:0];
    HKQuantity *quantity = sample.quantity;
    new_Updated_Data =[quantity doubleValueForUnit:[HKUnit unitFromString:@"count/min"]];
    NSLog(@"new quantity:%f",new_Updated_Data);
}];

[self.healthStore executeQuery:heartQuery];
NSLog(@"updated data %f",new_Updated_Data);


return avg_heartBeats;


//todo:- to get background update fast and easy

}

@DEEP PRADHAN Is this working for you now? I have the same problem. Can you please help me with the full code? — Vidhya Sri, Jul 10 '18 at 13:39

Gerd Castan · Accepted Answer · 2016-03-27T20:02:54.793

0

Use HKObserverQuery to get a long running query that is updated in background:

https://developer.apple.com/library/ios/documentation/HealthKit/Reference/HKObserverQuery_Class/index.html

As long as no HKWorkoutSessionis running, your watch measures the heart rate every 10 minutes, so you don't get more values. When a HKWorkoutSession is running on your watch, you get values more frequently.

If you want to dive into HKWorkoutSession, Allan has a detailed tutorial: https://developer.apple.com/videos/play/wwdc2015/203/

edited Mar 27 '16 at 20:02

answered Mar 26 '16 at 09:57

Gerd Castan

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What is the problem in HKAnchoredQuery? As I used update Handler? Can I use the same without WorkoutSession? – DEEP PRADHAN 12BIT0052 Mar 29 '16 at 07:28
No problem with `HKAnchoredQuery`. You can use it without `HKWorkoutSession` (`HKWorkoutSession` is only available on the watch). – Gerd Castan Mar 29 '16 at 11:03
Hey Gerd Thanks, now I am facing this issue. I am getting updated data but I need to multitask it and I want to get proper live data without multitasking and touching Health Kit.http://stackoverflow.com/questions/36277821/hkanchoredquery-update-handler-not-working-properly/36279850?noredirect=1#comment60186455_36279850 please help in this? – DEEP PRADHAN 12BIT0052 Mar 29 '16 at 11:50
I am using HKAnchoredQuery but I want to get all data on foreground of app without doing any multitask and re-opening of app? – DEEP PRADHAN 12BIT0052 Mar 29 '16 at 13:02
`HKAnchoredQuery` is a way to go. But no way without multitasking. Get accustomed to it :-) – Gerd Castan Mar 29 '16 at 16:17
So that means multitasking is necessary for getting updated value in HKAnchoredQuery? So according to my aim what will be good? so that I can get data on app without multitasking it? – DEEP PRADHAN 12BIT0052 Mar 30 '16 at 04:45
With irrelevant exceptions everything you get from HealthKit you get called back asynchronously. – Gerd Castan Mar 30 '16 at 07:02
Did not get you, can you tell w.r.t my code written in HKAnchoredQuery. – DEEP PRADHAN 12BIT0052 Mar 30 '16 at 07:06
I just do not want to do multitask and get the value. I want to get data updated data without refreshing it. – DEEP PRADHAN 12BIT0052 Mar 30 '16 at 09:28

Getting updated heart rate data from Health Kit

1 Answers1