Step Count Function skipping lines Swift - ios

Question

I have a function that takes the total number of steps recorded by the device, saves it to a variable, and then gets the step data from each day, adding them to another variable until the two have the same value. I need this in order to for the app to know when to stop when it is saving the all time step data to an array.
However, the second half of this function does not execute, and I have no idea why. Here is the function:
// allTimeStepTotal and allTimeStepSum are doubles that are defined with a value of 0.0
func stepsAllTime(completion: (Double, NSError?) -> () ) {
// The type of data we are requesting
let type = HKSampleType.quantityTypeForIdentifier(HKQuantityTypeIdentifierStepCount)
// Our search predicate which will fetch data from now until a day ago
let predicate = HKQuery.predicateForSamplesWithStartDate(NSDate.distantPast() as! NSDate, endDate: NSDate(), options: .None)
// The actual HealthKit Query which will fetch all of the steps and sub them up for us.
let query = HKSampleQuery(sampleType: type, predicate: predicate, limit: 0, sortDescriptors: nil) { query, results, error in
var steps: Double = 0
if results?.count > 0 {
for result in results as! [HKQuantitySample] {
steps += result.quantity.doubleValueForUnit(HKUnit.countUnit())
}
}
completion(steps, error)
self.allTimeStepsTotal += steps
println("Total:")
println(self.allTimeStepsTotal)
println("Sum:")
println(self.allTimeStepsSum)
}
self.healthKitStore.executeQuery(query)
println("Moving On")
var x = 1
while self.allTimeStepsTotal > self.allTimeStepsSum {
x += -1
// The type of data we are requesting
let sampleType = HKSampleType.quantityTypeForIdentifier(HKQuantityTypeIdentifierStepCount)
var daysAgo = -1 * x
var daysSince = (-1 * x) + 1
// Our search predicate which will fetch data from now until a day ago
let samplePredicate = HKQuery.predicateForSamplesWithStartDate(NSCalendar.currentCalendar().dateByAddingUnit(.CalendarUnitDay, value: daysAgo, toDate: NSDate(), options: nil), endDate: NSCalendar.currentCalendar().dateByAddingUnit(.CalendarUnitDay, value: daysSince, toDate: NSDate(), options: nil), options: .None)
// The actual HealthKit Query which will fetch all of the steps and sub them up for us.
let stepQuery = HKSampleQuery(sampleType: sampleType, predicate: samplePredicate, limit: 0, sortDescriptors: nil) { query, results, error in
var steps: Double = 0
if results?.count > 0 {
for result in results as! [HKQuantitySample] {
steps += result.quantity.doubleValueForUnit(HKUnit.countUnit())
}
}
completion(steps, error)
self.allTimeStepsSum += steps
println("New Sum:")
println(self.allTimeStepsSum)
}
self.healthKitStore.executeQuery(stepQuery)
}
And here is the call:
healthManager.stepsAllTime({Double, NSError in
println("All Done")
})
println("Finished executing stepsAllTime")
Can anyone tell me what I need to fix, or what went wrong?

Answer 1

Assuming that allTimeStepsTotal and allTimeStepsSum are initialized to 0.0, the second half of that function won't execute because the HKSampleQuery you've created executes asynchronously—that is, it calls the resultHandler at some time in the future after the the while loop in the second half of your function is evaluated. The condition self.allTimeStepsTotal > self.allTimeStepsSum will evaluate to false since both values are still 0.0, and the loop will not execute.