delay after requestAuthorizationToShareTypes - ios8

Question

I am setting up an iOS 8 app to request Heath Kit Store authorization to share types. The request Read/Write screen shows fine and on selecting Done, I see the completion callback immediately after. In this callback, I am pushing a new view controller. I set a breakpoint for the code that is programmatically pushing the next view controller and this is called immediately, but the transition doesn't occur until about 10 seconds later.
Some code:
#IBAction func enable(sender: AnyObject) {
let hkManager = HealthKitManager()
hkManager.setupHealthStoreIfPossible { (success, error) -> Void in
if let error = error {
println("error = \(error)")
} else {
println("enable HK success = \(success)")
self.nextStep()
}
}
}
func nextStep() {
self.nav!.pushViewController(nextController, animated: true)
}
class HealthKitManager: NSObject {
let healthStore: HKHealthStore!
override init() {
super.init()
healthStore = HKHealthStore()
}
class func isHealthKitAvailable() -> Bool {
return HKHealthStore.isHealthDataAvailable()
}
func setupHealthStoreIfPossible(completion: ((Bool, NSError!) -> Void)!) {
if HealthKitManager.isHealthKitAvailable()
{
healthStore.requestAuthorizationToShareTypes(dataTypesToWrite(), readTypes: dataTypesToRead(), completion: { (success, error) -> Void in
completion(success, error)
})
}
}
func dataTypesToWrite() -> NSSet {
let runningType = HKObjectType.quantityTypeForIdentifier(HKQuantityTypeIdentifierDistanceWalkingRunning)
let stepType = HKObjectType.quantityTypeForIdentifier(HKQuantityTypeIdentifierStepCount)
return NSSet(objects: runningType, stepType)
}
func dataTypesToRead() -> NSSet {
let runningType = HKObjectType.quantityTypeForIdentifier(HKQuantityTypeIdentifierDistanceWalkingRunning)
let stepType = HKObjectType.quantityTypeForIdentifier(HKQuantityTypeIdentifierStepCount)
let climbedType = HKObjectType.quantityTypeForIdentifier(HKQuantityTypeIdentifierFlightsClimbed)
return NSSet(objects: runningType, stepType, climbedType)
}
}
Any thoughts on what is causing the time delay for the transition?

Answer 1

The problem was that the completion block is returned in the background queue. I just put the transition call back onto the main queue as follows:
hkManager.setupHealthStoreIfPossible { (success, error) -> Void in
if let error = error {
println("error = \(error)")
} else {
dispatch_async(dispatch_get_main_queue(), {
println("enable HK success = \(success)")
self.nextStep()
});
}
}
}