HealthKit Swift getting today's steps

Question

I am making a swift iOS app that integrates with a user\'s step count as reported by the Health app. I can easily find the user\'s step count in the last hour, using this as

Answer 1

Here is the right way using HKStatisticsCollectionQuery courtesy of the direction from the code above.

This is written in Swift 3 so you may have to convert some of the code back to 2.3 or 2 if not on 3 yet.

Swift 3

 func retrieveStepCount(completion: (stepRetrieved: Double) -> Void) {

        //   Define the Step Quantity Type
        let stepsCount = HKQuantityType.quantityType(forIdentifier: HKQuantityTypeIdentifier.stepCount)

        //   Get the start of the day         
        let date = Date()
        let cal = Calendar(identifier: Calendar.Identifier.gregorian)
        let newDate = cal.startOfDay(for: date)

        //  Set the Predicates & Interval
        let predicate = HKQuery.predicateForSamples(withStart: newDate, end: Date(), options: .strictStartDate)
        var interval = DateComponents()
        interval.day = 1

        //  Perform the Query
        let query = HKStatisticsCollectionQuery(quantityType: stepsCount!, quantitySamplePredicate: predicate, options: [.cumulativeSum], anchorDate: newDate as Date, intervalComponents:interval)

        query.initialResultsHandler = { query, results, error in

            if error != nil {

                //  Something went Wrong
                return
            }

            if let myResults = results{
                myResults.enumerateStatistics(from: self.yesterday, to: self.today) {
                    statistics, stop in

                    if let quantity = statistics.sumQuantity() {

                        let steps = quantity.doubleValue(for: HKUnit.count())

                        print("Steps = \(steps)")
                        completion(stepRetrieved: steps)

                    }
                }
            }


        }

        storage.execute(query)
    }

Objective-C

HKQuantityType *type = [HKSampleType quantityTypeForIdentifier:HKQuantityTypeIdentifierStepCount];

NSDate *today = [NSDate date];
NSDate *startOfDay = [[NSCalendar calendarWithIdentifier:NSCalendarIdentifierGregorian] startOfDayForDate:today];

NSPredicate *predicate = [HKQuery predicateForSamplesWithStartDate:startOfDay endDate:today options:HKQueryOptionStrictStartDate];
NSDateComponents *interval = [[NSDateComponents alloc] init];
interval.day = 1;

HKStatisticsCollectionQuery *query = [[HKStatisticsCollectionQuery alloc] initWithQuantityType:type quantitySamplePredicate:predicate options:HKStatisticsOptionCumulativeSum anchorDate:startOfDay intervalComponents:interval];

query.initialResultsHandler = ^(HKStatisticsCollectionQuery * _Nonnull query, HKStatisticsCollection * _Nullable result, NSError * _Nullable error) {
  if (error != nil) {
    // TODO
  } else {
    [result enumerateStatisticsFromDate:startOfDay toDate:today withBlock:^(HKStatistics * _Nonnull result, BOOL * _Nonnull stop) {
      HKQuantity *quantity = [result sumQuantity];
      double steps = [quantity doubleValueForUnit:[HKUnit countUnit]];
      NSLog(@"Steps : %f", steps);
    }];
  }
};

[self.storage executeQuery:query];