iOS HealthKit how to save Heart Rate (bpm) values? Swift

Swift : Heart Rate (bpm) save into healthkit store

 private func saveHeartRateIntoHealthStore(height:Double) -> Void    {        // Save the user's heart rate into HealthKit.        let heartRateUnit: HKUnit = HKUnit.countUnit().unitDividedByUnit(HKUnit.minuteUnit())        let heartRateQuantity: HKQuantity = HKQuantity(unit: heartRateUnit, doubleValue: height)        var heartRate : HKQuantityType = HKQuantityType.quantityTypeForIdentifier(HKQuantityTypeIdentifierHeartRate)        let nowDate: NSDate = NSDate()        let heartRateSample: HKQuantitySample = HKQuantitySample(type: heartRate            , quantity: heartRateQuantity, startDate: nowDate, endDate: nowDate)        let completion: ((Bool, NSError!) -> Void) = {            (success, error) -> Void in            if !success {                println("An error occured saving the Heart Rate sample \(heartRateSample). In your app, try to handle this gracefully. The error was: \(error).")                abort()            }        }        self.healthStore!.saveObject(heartRateSample, withCompletion: completion)    }// end saveHeartRateIntoHealthStore

In Swift 3:

func saveHeartRate(date: Date = Date(), heartRate heartRateValue: Double, completion completionBlock: @escaping (Bool, Error?) -> Void) {    let unit = HKUnit.count().unitDivided(by: HKUnit.minute())    let quantity = HKQuantity(unit: unit, doubleValue: heartRateValue)    let type = HKQuantityType.quantityType(forIdentifier: .heartRate)!    let heartRateSample = HKQuantitySample(type: type, quantity: quantity, start: date, end: date)    self.healthKitStore.save(heartRateSample) { (success, error) -> Void in        if !success {            print("An error occured saving the HR sample \(heartRateSample). In your app, try to handle this gracefully. The error was: \(error).")        }        completionBlock(success, error)    }}

In ObjectiveC (for those not using Swift, expanded for easy reading):

#define nilable __nullable#define kCountPerMinUnitStr @"count/min"typedef void (^VoidBoolErrorBlock) (BOOL        success,                                    NSError *   nilable error);enum {    // Memory Constants    kNil       = 0,    kNilUPP    = 0,    kNilRefCon = 0};/** writes a weight sample to HealthKit @param weight as HKQuantityTypeIdentifierBodyMass */- (void) writeCDAHeartRateSample: ( NSStringPtr ) valueStr                        cdaUnits: ( NSStringPtr ) cdaUnits                            date: ( NSDate * ) date {      // was (CGFloat)    double  theValue = kNil;    // Each quantity consists of a value and a unit.    HKUnit *            theMeasurementUnit = nil;    HKQuantity *        theQuantity        = nil;    HKQuantityType *    theHeartRateType   = nil;    NSDate *            theDate            = nil;    // For every sample, we need a sample type, quantity and a date.    HKQuantitySample *  theSample = nil;    VoidBoolErrorBlock  theBlock  = nil;    theValue           = [ valueStr integerValue ];//    theMeasurementUnit = [ HKUnit unitFromCDAString: cdaUnits ];    theMeasurementUnit = [ HKUnit unitFromString: kCountPerMinUnitStr ];    /// FIXME: temp code StackOverflow example    theQuantity        = [ HKQuantity quantityWithUnit: theMeasurementUnit                                           doubleValue: theValue ];    theHeartRateType = [ HKQuantityType quantityTypeForIdentifier: HKQuantityTypeIdentifierHeartRate ];    theDate          = ( date != nil ) ? date : [ NSDate date ];///???: default to today's date?    theBlock = [ self saveCDAHeartRateObjectBlock: theValue ];    // For every sample, we need a sample type, quantity and a date.    theSample = [HKQuantitySample quantitySampleWithType: theHeartRateType                                                      quantity: theQuantity                                                     startDate: theDate                                                       endDate: theDate];    [ self.healthStore saveObject: theSample                   withCompletion: theBlock ];}/** companion block encapsulation for writeCDAHeartRateSample{} @return  completion block for saveObject: withCompletion in writeCDAHeartRateSample{} */- ( VoidBoolErrorBlock ) saveCDAHeartRateObjectBlock: ( double ) value {    VoidBoolErrorBlock theResult = nil;    theResult = ^(BOOL success, NSError *error) {        if (!success) {            ///NSLog(@"Error while saving Heart Rate (%f) to Health Store: %@.", value, error);        }    };    return theResult;}