HealthKit – How to get Running Activity in splits of distance (each kilometre)?

Question

Title says it all, I've been scratching my head for a couple of days trying to work it out. Basing off the already stored data from previous workouts from the  Watch:

Originally hoped to have used a HKStatisticsQuery with a combination of HKStatisticsOptions.CumulativeSum and the missing element being telling the query to get per kilometre data.

Now struggling with Workout events (pauses throwing my logic out)

So the output would be the distance 1km and the duration that km took. Any ideas for improvement, please help?

Thanks to Allan's direction below I've managed to get closer in two parts, one grabbing the workout:

 print("👣HealthKit Workout:")    
    let healthStore:HKHealthStore = HKHealthStore()
    let durationFormatter = NSDateComponentsFormatter()
    var workouts = [HKWorkout]()

    // Predicate to read only running workouts
    let predicate = HKQuery.predicateForWorkoutsWithWorkoutActivityType(HKWorkoutActivityType.Running)
    // Order the workouts by date
    let sortDescriptor = NSSortDescriptor(key:HKSampleSortIdentifierStartDate, ascending: false)
    // Create the query
    let sampleQuery = HKSampleQuery(sampleType: HKWorkoutType.workoutType(), predicate: predicate, limit: 0, sortDescriptors: [sortDescriptor])
    { (sampleQuery, results, error ) -> Void in
    if let queryError = error {
                    print( "There was an error while reading the samples: \(queryError.localizedDescription)")
                }

                workouts = results as! [HKWorkout]

                let target:Int = 0
                print(workouts[target].workoutEvents)
                print("Energy ", workouts[target].totalEnergyBurned)
                print(durationFormatter.stringFromTimeInterval(workouts[target].duration))
                print((workouts[target].totalDistance!.doubleValueForUnit(HKUnit.meterUnit())))

                self.coolMan(workouts[target])
                self.coolManStat(workouts[target])
        }

        // Execute the query
        healthStore.executeQuery(sampleQuery)

Second is processing the samples into splits:

  let distanceType =  HKObjectType.quantityTypeForIdentifier(HKQuantityTypeIdentifierDistanceWalkingRunning)
    let workoutPredicate = HKQuery.predicateForObjectsFromWorkout(workout)
    let startDateSort =  NSSortDescriptor(key: HKSampleSortIdentifierStartDate, ascending: true)

    let query = HKSampleQuery(sampleType: distanceType!, predicate: workoutPredicate,
        limit: 0, sortDescriptors: [startDateSort]) {
            (sampleQuery, results, error) -> Void in

            // Process the detailed samples...
            if let distanceSamples = results as? [HKQuantitySample] {

                var count = 0.00
                var firstStart = distanceSamples[0].startDate
                let durationFormatter = NSDateComponentsFormatter()

                for (index, element) in distanceSamples.enumerate() {
                    count +=  element.quantity.doubleValueForUnit(HKUnit.meterUnit())
                    //print("Item \(index): \(element.quantity)  -  \(count) - \(element.startDate) \(element.endDate)")
                    if count > 1000 {
                        print("We reached a kilometer")

                        /* Print The Split Time Taken */
                        print(durationFormatter.stringFromTimeInterval(round((distanceSamples[index+1].endDate.timeIntervalSinceDate(firstStart)))))
                        firstStart = distanceSamples[index+1].endDate;
                        count = 0.00
                    }
                }

Answer 1

You'll need to process the raw samples from the workout in order and sum them together yourself to figure out where the splits are, I think. There isn't any clever way I can think of to compose an HKStatisticsQuery or HKStatisticsCollectionQuery that would somehow do that work for you.