iOS run async method on background task? - ios

Question

Stack Overflow. Here is what I´m dealing with.
I´m developing an iOS 8 app that starts monitoring significant location changes when app is terminated using startMonitoringSignificantLocationChanges(). Until here everything works fine. The app relaunches when it get a location change with the application:didFinishLaunchingWithOptions:. I configure a CLLocationManager object and get the CLLocation like it says in Apple reference:
If you start this service and your app is subsequently terminated, the
system automatically relaunches the app into the background if a new
event arrives. In such a case, the options dictionary passed to the
application:willFinishLaunchingWithOptions: and
application:didFinishLaunchingWithOptions: methods of your app
delegate contains the key UIApplicationLaunchOptionsLocationKey to
indicate that your app was launched because of a location event. Upon
relaunch, you must still configure a location manager object and call
this method to continue receiving location events. When you restart
location services, the current event is delivered to your delegate
immediately. In addition, the location property of your location
manager object is populated with the most recent location object even
before you start location services.
Like I said, this works pretty well. My problem is when I try to fetch data from a web service (like Twitter API with TwitterKit) with a asynchronous method; I just not get onto the completion handler. I was researching a lot about this subject and I read that apparently the method I use is running in its own thread.
Here is how I listen to the location change launch and create the background task:
var locationManager: CLLocationManager!
var bgTaskId: UIBackgroundTaskIdentifier!
func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
// API keys configuration
if let options = launchOptions {
if options[UIApplicationLaunchOptionsLocationKey] != nil {
self.bgTaskId = UIApplication.sharedApplication().beginBackgroundTaskWithExpirationHandler({ () -> Void in
UIApplication.sharedApplication().endBackgroundTask(self.bgTaskId)
self.bgTaskId = UIBackgroundTaskInvalid
})
// Location manager configuration
// Async func
theAsyncRequest(){ (response) -> Void in
//
// NEVER GETS HERE
//
UIApplication.sharedApplication().endBackgroundTask(self.bgTaskId)
self.bgTaskId = UIBackgroundTaskInvalid
}
}
return true
}
// Some code when app launches the normal way
return true
}
I tried the same with a synchronous method like in Parse Framework eg. let objects = someQuery.findObjects() and it worked. But it doesn´t with an asynchronous method.
What do I´m missing in here? Is it possible what I´m trying to accomplish? I know this would be an easy task if I´d use a synchronous method.
Thanks in advance.