Get total step count for every date in HealthKit

Question

What\'s the best way to get a total step count for every day recorded in HealthKit. With HKSampleQuery\'s method initWithSampleType (see below) I can set a star

Answer 1

You should use HKStatisticsCollectionQuery:

NSCalendar *calendar = [NSCalendar currentCalendar];
NSDateComponents *interval = [[NSDateComponents alloc] init];
interval.day = 1;

NSDateComponents *anchorComponents = [calendar components:NSCalendarUnitDay | NSCalendarUnitMonth | NSCalendarUnitYear
                                                 fromDate:[NSDate date]];
anchorComponents.hour = 0;
NSDate *anchorDate = [calendar dateFromComponents:anchorComponents];
HKQuantityType *quantityType = [HKObjectType quantityTypeForIdentifier:HKQuantityTypeIdentifierStepCount];

// Create the query
HKStatisticsCollectionQuery *query = [[HKStatisticsCollectionQuery alloc] initWithQuantityType:quantityType
                                                                       quantitySamplePredicate:nil
                                                                                       options:HKStatisticsOptionCumulativeSum
                                                                                    anchorDate:anchorDate
                                                                            intervalComponents:interval];

// Set the results handler
query.initialResultsHandler = ^(HKStatisticsCollectionQuery *query, HKStatisticsCollection *results, NSError *error) {
    if (error) {
        // Perform proper error handling here
        NSLog(@"*** An error occurred while calculating the statistics: %@ ***",error.localizedDescription);
    }

    NSDate *endDate = [NSDate date];
    NSDate *startDate = [calendar dateByAddingUnit:NSCalendarUnitDay
                                             value:-7
                                            toDate:endDate
                                           options:0];

    // Plot the daily step counts over the past 7 days
    [results enumerateStatisticsFromDate:startDate
                                  toDate:endDate
                               withBlock:^(HKStatistics *result, BOOL *stop) {

                                   HKQuantity *quantity = result.sumQuantity;
                                   if (quantity) {
                                       NSDate *date = result.startDate;
                                       double value = [quantity doubleValueForUnit:[HKUnit countUnit]];
                                       NSLog(@"%@: %f", date, value);
                                   }

                               }];
};

[self.healthStore executeQuery:query];