CLRegionState is coming Unknown while requesting a state from the location manager? - ios

Question

I am building a feature related to region monitoring while starting region monitoring I am requesting the state as shown below in code. On some of the devices, I am getting region state Unknown all the time. If I switch Wifi On or Off or plug the charger into it. It starts working fine.
How can I make it more reliable on a cellular network?
Please, note I took all location permissions from the user before making any region monitoring or state request calls.
private func initiateLocationManager() {
locationManager = CLLocationManager()
locationManager.delegate = self
locationManager.distanceFilter = kCLLocationAccuracyBest
locationManager.requestAlwaysAuthorization()
}
func startMonitoring(alarm: StationAlarm) {
if LocationManager.sharedInstance.isRegionMonitoringAvailable() {
let coordinate = CLLocationCoordinate2D(latitude: stationLatitude, longitude: stationLongitude)
// 1
let region = CLCircularRegion(center: coordinate, radius: CLLocationDistance(radius * 1000), identifier: alarm.alarmId)
// 2
region.notifyOnEntry = true
region.notifyOnExit = false
// 4
locationManager.startMonitoring(for: region)
Utility.delay(0.1) { [weak self] in
self?.locationManager.requestState(for: region)
}
}
}
func locationManager(_: CLLocationManager, didDetermineState state: CLRegionState, for region: CLRegion) {
Log.event("Region State is \(state.rawValue)")
}

Answer 1

The issue is, you are calling the requestState using a hard-coded delay - (0.1). How do you make sure the Location Manager started monitoring your region within 0.1 seconds? You will get the exact region state of a region, only if started monitoring it.
The better method for overcoming this problem is, implement the didStartMonitoringForRegion delegate and call requestStateForRegion
locationManager.startMonitoring(for: region)
func locationManager(_ manager: CLLocationManager, didStartMonitoringFor region: CLRegion) {
manager.requestState(for: region)
}
func locationManager(_ manager: CLLocationManager, didDetermineState state: CLRegionState, for region: CLRegion) {
if (region is CLBeaconRegion) && state == .inside {
locationManager(manager, didEnterRegion: region)
}
}

Answer 2

From the CLLocationManager requestState(for:) docs:
region: The region whose state you want to know. This object must be an instance of one of the standard region subclasses provided by Map Kit. You cannot use this method to determine the state of custom regions you define yourself.
You defined the region yourself so you can't use requestState(for:) to get its state. You use that function with regions that you get back from Core Location (via the delegate methods).
If you want to know whether the device is currently inside a region, start a standard location update request (startUpdatingLocation() etc) and when you get back a recent and accurate coordinate, use the CLCircularRegion contains() function to check the coordinate.
// In the locationManager(_:didUpdateLocations:) delegate method
if myCircularRegion.contains(myCoordinate) {
// ...
}