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

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)
}