Display "Cannot find iBeacon" message - ios

Question

My question is very simple. I would like to display an error message i.e. "Cannot find iBeacon" if iBeacon monitoring fails, after calling startSearchingForSessions via a button press after being called in viewDidLoad
override func viewDidLoad() {
super.viewDidLoad()
self.locationManager = CLLocationManager()
if self.locationManager.responds(to: #selector(CLLocationManager.requestWhenInUseAuthorization)) {
self.locationManager.requestWhenInUseAuthorization()
}
self.locationManager.delegate = self
self.locationManager.pausesLocationUpdatesAutomatically = false
let uuid = UUID(uuidString: "869A6E2E-AE14-4CF5-8313-8D6976058A7A")
self.beaconRegion = CLBeaconRegion(proximityUUID: uuid!, identifier: "com.dejordan.myapp"
startSearchingForSessions()
}
func startSearchingForSessions() {
// Start looking for the beacons with that UUID and Identifier.
self.locationManager.startMonitoring(for: self.beaconRegion)
self.locationManager.startRangingBeacons(in: self.beaconRegion)
self.locationManager.startUpdatingLocation()
}
And handling the found beacons thusly:
// Required by the Location Manager.
func locationManager(_ manager: CLLocationManager, didEnterRegion region: CLRegion) {
self.locationManager.startRangingBeacons(in: self.beaconRegion)
}
func locationManager(_ manager: CLLocationManager, didDetermineState state: CLRegionState, for region: CLRegion) {
if state == CLRegionState.outside {
print("Cannot Find Beacon")
}
}
// Required by the Location Manager.
func locationManager(_ manager: CLLocationManager, didExitRegion region: CLRegion) {
self.locationManager.stopRangingBeacons(in: self.beaconRegion)
}
// This is called if any beacons are found.
func locationManager(_ manager: CLLocationManager, didRangeBeacons beacons: [CLBeacon], in region: CLBeaconRegion) {
var result = Array<CLBeacon>()
for beacon in beacons {
result.append(beacon)
}
foundBeacons = result
// If we found any, we need to see
// what class they belong to based on information
// from Parse.
self.identifyFoundBeacons()
// We can stop looking for beacons now.
self.locationManager.stopMonitoring(for: self.beaconRegion)
self.locationManager.stopRangingBeacons(in: self.beaconRegion)
self.locationManager.stopUpdatingLocation()
}
I have implemented the delegate error methods in an attempt to find where this occurs but thus far in navigating the mounds of documentation on iBeacon I have come up fruitless.
func locationManager(_ manager: CLLocationManager, didFailWithError error: Error) {
print("Location manager failed: \(error.localizedDescription)")
}
func locationManager(_ manager: CLLocationManager, monitoringDidFailFor region: CLRegion?, withError error: Error) {
print("Failed monitoring region: \(error.localizedDescription)")
}
Thank you!

Answer 1

If you simply want to know when beacons are not detected (vs. when there was a low-level failure to look for beacons), then simply use the following delegate method:
public func locationManager(_ manager: CLLocationManager, didDetermineState state: CLRegionState, for region: CLRegion) {
if state == CLRegionState.outside {
print("Cannot find beacon")
}
}

Answer 2

Interestingly enough, didRangeBeacons in the delegate method
func locationManager(_ manager: CLLocationManager, didRangeBeacons beacons: [CLBeacon], in region: CLBeaconRegion)
gets called with an empty array of [CLBeacon]s, wherein I can use the beacons array size to determine whether or not any beacons were found.
Not what I expected, but this has solved my problem!