How to check if user's current location is inside a location circle - ios

Question

i want to check if user if inside a vicinity. For example i have specified a radius of 50 meters around current of location of user. Let's say if user is moving, now i want to check if user in inside 50 meter radius or not. Here is my code
override func viewDidLoad() {
super.viewDidLoad()
locationManager.startMonitoringVisits()
locationManager.delegate = self
locationManager.distanceFilter = 1
locationManager.allowsBackgroundLocationUpdates = true
locationManager.startUpdatingLocation()
}
Here is code for checking distance
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
guard let location = locations.first else {
return
}
let officeLocation = CLLocationCoordinate2D.init(latitude: 31.471303736482234, longitude: 74.27275174139386)
let circle = MKCircle(center: officeLocation, radius: 50 as CLLocationDistance)
if location.distance(from: officeLocation) > circle.radius {
self.newVisitReceived(des: "YOU ARE OUT OF OFFICE")
}
else{
self.newVisitReceived(des: "YOU ARE IN OFFICE")
}
}
Even if i don't move this code sends notification "YOU ARE OUT".

Answer 1

I would solve this with Geofences...
You have to specify a coordinate center & radius where you want to listen to the user when he goes inside/outside from your geofence.
override func viewDidLoad() {
super.viewDidLoad()
let locationManager = CLLocationManager()
locationManager.delegate = self
locationManager.desiredAccuracy = kCLLocationAccuracyBestForNavigation
locationManager.allowsBackgroundLocationUpdates = true
locationManager.requestAlwaysAuthorization()
}
func locationManager(_ manager: CLLocationManager, didChangeAuthorization status: CLAuthorizationStatus) {
if status == .authorizedAlways || status == .authorizedWhenInUse {
// CLLocationCoordinate2D; You have to put the coordinate that you want to listen
let region = CLCircularRegion(center: CLLocationCoordinate2D(latitude: 324234, longitude: 23423), radius: 50, identifier: "Ur ID")
region.notifyOnExit = true
region.notifyOnEntry = true
manager.startMonitoring(for: region)
}
}
func locationManager(_ manager: CLLocationManager, didExitRegion region: CLRegion) {
// User has exited from ur regiom
}
func locationManager(_ manager: CLLocationManager, didEnterRegion region: CLRegion) {
// User has exited from ur region
}
I hope this will be useful

Answer 2

The general problem with location services is that the measurements vary in accuracy, depending on a lot of factors. How would your like your code to behave if the user is standing right on the 50 meter boundary? Your current code would then flip back and forth randomly between 'in office' and 'out of office', if the accuracy is bad.
I think accuracy of a GPS is actually more than 4 meters under the best conditions, so a distanceFilter of 1 might not be appropriate.
I guess you would need some state in your app that tracks when the user was last seen inside the 50 meter radius, and also some grace period before updating that variable again, to avoid 'flickering'.