Get total step count for every date in HealthKit - objective-c

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 start and end date for the query using NSPredicate, but the method returns an array with many HKQuantitySamples per day.
- (instancetype)initWithSampleType:(HKSampleType *)sampleType
predicate:(NSPredicate *)predicate
limit:(NSUInteger)limit
sortDescriptors:(NSArray *)sortDescriptors
resultsHandler:(void (^)(HKSampleQuery *query,
NSArray *results,
NSError *error))resultsHandler
I guess I can query all recorded step counts and go through the array and calculate the total step count for each day, but I'm hoping for an easier solution as there will be thousands of HKSampleQuery objects. Is there a way to have initWithSampleType return a total step count per day?

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];

Answer 2

Port to Swift with no dependency to SwiftDate library
let calendar = NSCalendar.current
let interval = NSDateComponents()
interval.day = 1
var anchorComponents = calendar.dateComponents([.day, .month, .year], from: NSDate() as Date)
anchorComponents.hour = 0
let anchorDate = calendar.date(from: anchorComponents)
// Define 1-day intervals starting from 0:00
let stepsQuery = HKStatisticsCollectionQuery(quantityType: stepsCount!, quantitySamplePredicate: nil, options: .cumulativeSum, anchorDate: anchorDate!, intervalComponents: interval as DateComponents)
// Set the results handler
stepsQuery.initialResultsHandler = {query, results, error in
let endDate = NSDate()
let startDate = calendar.date(byAdding: .day, value: -7, to: endDate as Date, wrappingComponents: false)
if let myResults = results{
myResults.enumerateStatistics(from: startDate!, to: endDate as Date) { statistics, stop in
if let quantity = statistics.sumQuantity(){
let date = statistics.startDate
let steps = quantity.doubleValue(for: HKUnit.count())
print("\(date): steps = \(steps)")
//NOTE: If you are going to update the UI do it in the main thread
DispatchQueue.main.async {
//update UI components
}
}
} //end block
} //end if let
}
healthStore?.execute(stepsQuery)

Answer 3

Modified #sebastianr's answer using core Swift classes, for just for testing I am returning only steps for just one day, once you have more days you can create a dictionary of Dates and step count and return it
func getStepCountPerDay(completion:#escaping (_ count: Double)-> Void){
guard let sampleType = HKObjectType.quantityType(forIdentifier: .stepCount)
else {
return
}
let calendar = Calendar.current
var dateComponents = DateComponents()
dateComponents.day = 1
var anchorComponents = calendar.dateComponents([.day, .month, .year], from: Date())
anchorComponents.hour = 0
let anchorDate = calendar.date(from: anchorComponents)
let stepsCumulativeQuery = HKStatisticsCollectionQuery(quantityType: sampleType, quantitySamplePredicate: nil, options: .cumulativeSum, anchorDate: anchorDate!, intervalComponents: dateComponents
)
// Set the results handler
stepsCumulativeQuery.initialResultsHandler = {query, results, error in
let endDate = Date()
let startDate = calendar.date(byAdding: .day, value: 0, to: endDate, wrappingComponents: false)
if let myResults = results{
myResults.enumerateStatistics(from: startDate!, to: endDate as Date) { statistics, stop in
if let quantity = statistics.sumQuantity(){
let date = statistics.startDate
let steps = quantity.doubleValue(for: HKUnit.count())
print("\(date): steps = \(steps)")
completion(steps)
//NOTE: If you are going to update the UI do it in the main thread
DispatchQueue.main.async {
//update UI components
}
}
} //end block
} //end if let
}
HKHealthStore().execute(stepsCumulativeQuery)
}

Answer 4

Here is a translation that currently works for Swift 2.0, using the SwiftDate library.
let type = HKSampleType.quantityTypeForIdentifier(HKQuantityTypeIdentifierStepCount)
let startDate = NSDate().beginningOfDay().oneWeekAgo()
let interval = NSDateComponents()
interval.day = 1
let predicate = HKQuery.predicateForSamplesWithStartDate(startDate, endDate: NSDate(), options: .StrictStartDate)
let query = HKStatisticsCollectionQuery(quantityType: type!, quantitySamplePredicate: predicate, options: [.CumulativeSum], anchorDate: NSDate().begginingOfDay(), intervalComponents:interval)
query.initialResultsHandler = { query, results, error in
let endDate = NSDate()
let startDate = NSDate().beginningOfDay().oneWeekAgo()
if let myResults = results{
myResults.enumerateStatisticsFromDate(startDate, toDate: endDate) {
statistics, stop in
if let quantity = statistics.sumQuantity() {
let date = statistics.startDate
let steps = quantity.doubleValueForUnit(HKUnit.countUnit())
print("\(date): steps = \(steps)")
}
}
}
}
healthKitStore.executeQuery(query)

Answer 5

I wrapped mine in a completion block (objective -c). I found what was best was to set the startDate for the query to todays date at midnight. Hope this helps, feel free to copy/paste to get started
-(void)fetchHourlyStepsWithCompletionHandler:(void (^)(NSMutableArray *, NSError *))completionHandler {
NSMutableArray *mutArray = [NSMutableArray new];
NSCalendar *calendar = [NSCalendar autoupdatingCurrentCalendar];
NSDate *startDate = [calendar dateBySettingHour:0 minute:0 second:0 ofDate:[NSDate date] options:0];
NSDate *endDate = [NSDate date]; // Whatever you need in your case
HKQuantityType *type = [HKObjectType quantityTypeForIdentifier:HKQuantityTypeIdentifierStepCount];
// Your interval: sum by hour
NSDateComponents *intervalComponents = [[NSDateComponents alloc] init];
intervalComponents.hour = 1;
// Example predicate
NSPredicate *predicate = [HKQuery predicateForSamplesWithStartDate:startDate endDate:endDate options:HKQueryOptionStrictStartDate];
HKStatisticsCollectionQuery *query = [[HKStatisticsCollectionQuery alloc] initWithQuantityType:type quantitySamplePredicate:predicate options:HKStatisticsOptionCumulativeSum anchorDate:startDate intervalComponents:intervalComponents];
query.initialResultsHandler = ^(HKStatisticsCollectionQuery *query, HKStatisticsCollection *results, NSError *error) {
[results enumerateStatisticsFromDate:startDate toDate:endDate
withBlock:^(HKStatistics *result, BOOL *stop) {
if (!result) {
if (completionHandler) {
completionHandler(nil, error);
}
return;
}
HKQuantity *quantity = result.sumQuantity;
NSDate *startDate = result.startDate;
NSDateFormatter *formatter = [[NSDateFormatter alloc]init];
formatter.dateFormat = #"h a";
NSString *dateString = [formatter stringFromDate:startDate];
double steps = [quantity doubleValueForUnit:[HKUnit countUnit]];
NSDictionary *dict = #{#"steps" : #(steps),
#"hour" : dateString
};
[mutArray addObject:dict];
}];
if (completionHandler) {
completionHandler(mutArray, error);
}
};
[self.healthStore executeQuery:query];
}

Answer 6

With Updated Swift 2.0 & SwiftDate library.
let type = HKSampleType.quantityTypeForIdentifier(HKQuantityTypeIdentifierStepCount)
let startDate = NSDate().beginningOfDay
let interval = NSDateComponents()
interval.day = 1
let predicate = HKQuery.predicateForSamplesWithStartDate(startDate, endDate: NSDate(), options: .StrictStartDate)
let query = HKStatisticsCollectionQuery(quantityType: type!, quantitySamplePredicate: predicate, options: [.CumulativeSum], anchorDate: NSDate().beginningOfDay, intervalComponents:interval)
query.initialResultsHandler = { query, results, error in
let endDate = NSDate()
let startDate = NSDate().beginningOfDay
if let myResults = results{
myResults.enumerateStatisticsFromDate(startDate, toDate: endDate) {
statistics, stop in
if let quantity = statistics.sumQuantity() {
let date = statistics.startDate
let steps = quantity.doubleValueForUnit(HKUnit.countUnit())
print("\(date): steps = \(steps)")
}
}
}
}
healthKitStore.executeQuery(query)