Core Location & Geofencing

Info.plist Keys

Add usage descriptions:

• NSLocationWhenInUseUsageDescription
• NSLocationAlwaysAndWhenInUseUsageDescription

Requesting Permission

import CoreLocation

class LocationManager: NSObject, ObservableObject, CLLocationManagerDelegate {
    private let manager = CLLocationManager()
    @Published var location: CLLocation?
    
    override init() {
        super.init()
        manager.delegate = self
    }
    
    func requestPermission() {
        manager.requestWhenInUseAuthorization()
    }
    
    func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
        location = locations.last
    }
    
    func locationManagerDidChangeAuthorization(_ manager: CLLocationManager) {
        if manager.authorizationStatus == .authorizedWhenInUse {
            manager.startUpdatingLocation()
        }
    }
}

Authorization Status

• .notDetermined — Not yet requested
• .restricted — Restricted by parental controls
• .denied — User denied
• .authorizedWhenInUse — Foreground access
• .authorizedAlways — Background access

Start Location Updates

manager.requestLocation()  // One-time
manager.startUpdatingLocation()  // Continuous

Location Accuracy

manager.desiredAccuracy = kCLLocationAccuracyBest  // Highest accuracy
manager.desiredAccuracy = kCLLocationAccuracyHundredMeters  // Battery efficient
manager.distanceFilter = 100  // Update every 100 meters

Reverse Geocoding

let geocoder = CLGeocoder()
geocoder.reverseGeocodeLocation(location) { placemarks, error in
    if let placemark = placemarks?.first {
        print(placemark.name, placemark.locality, placemark.country)
    }
}

Location Value

if let location = location {
    print("Lat: \(location.coordinate.latitude)")
    print("Lon: \(location.coordinate.longitude)")
    print("Alt: \(location.altitude)")
    print("Speed: \(location.speed)")
}

Define a Region

let region = CLCircularRegion(
    center: CLLocationCoordinate2D(latitude: 37.7749, longitude: -122.4194),
    radius: 100,
    identifier: "Office"
)
region.notifyOnEntry = true
region.notifyOnExit = true

Monitor Region

manager.startMonitoring(for: region)

func locationManager(_ manager: CLLocationManager, didEnterRegion region: CLRegion) {
    print("Entered \(region.identifier)")
}

func locationManager(_ manager: CLLocationManager, didExitRegion region: CLRegion) {
    print("Exited \(region.identifier)")
}

Background Location

For always-on monitoring, use requestAlwaysAuthorization() and configure background modes in Info.plist.

Significant Location Changes

manager.startMonitoringSignificantLocationChanges()