Core Location in MVP - ios

Question

In my project I have a LocationService class that conforms to CLLocationManagerDelegate protocol in order to detect current user's location.
class LocationService: NSObject, CLLocationManagerDelegate {
fileprivate let locationManager = CLLocationManager()
var location: Location? // Location(lat: Double, lon: Double)
override init() {
super.init()
locationManager.delegate = self
locationManager.desiredAccuracy = kCLLocationAccuracyHundredMeters
}
func getCurrentLocation() -> Location? {
locationManager.startUpdatingLocation()
// how can I catch a location?
return location
}
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
if let location = locations.last {
if location.horizontalAccuracy > 0 {
locationManager.stopUpdatingLocation()
self.location = Location(lat: location.coordinate.latitude, lon: location.coordinate.latitude)
}
}
}
func locationManager(_ manager: CLLocationManager, didFailWithError error: Error) {
print(error.localizedDescription)
}
}
I want my WeatherPresenter to trigger location updates in LocationService and get the result as soon as location is found. Is there any way to do this?
class WeatherPresenter {
unowned let delegate: WeatherViewDelegate
let weatherService = WeatherService()
let locationService = LocationService()
init(with delegate: WeatherViewDelegate) {
self.delegate = delegate
}
func getWeatherForCurrentLocation() {
if let location = locationService.getCurrentLocation() {
//...
}
}
}

Answer 1

You can use Delegate to notify WeatherPresenter on changes from LocationService
protocol LocationServiceDelegate: class { // Delegate protocol
func didUpdateLocation()
}
class LocationService: NSObject, CLLocationManagerDelegate {
weak var delegate: LocationServiceDelegate?
fileprivate let locationManager = CLLocationManager()
var location: Location? // Location(lat: Double, lon: Double)
override init() {
super.init()
locationManager.delegate = self
locationManager.desiredAccuracy = kCLLocationAccuracyHundredMeters
}
func startUpdatingLocation() { // Start updating called from presenter
locationManager.startUpdatingLocation()
}
func getCurrentLocation() -> Location? {
// how can I catch a location?
return location
}
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
if let location = locations.last {
if location.horizontalAccuracy > 0 {
locationManager.stopUpdatingLocation()
self.location = Location(lat: location.coordinate.latitude, lon: location.coordinate.latitude)
self.delegate?.didUpdateLocation() // Notify delegate on change
}
}
}
func locationManager(_ manager: CLLocationManager, didFailWithError error: Error) {
print(error.localizedDescription)
}
}
class WeatherPresenter: LocationServiceDelegate {
unowned let delegate: WeatherViewDelegate
let weatherService = WeatherService()
let locationService = LocationService()
init(with delegate: WeatherViewDelegate) {
self.delegate = delegate
self.locationService.delegate = self // Set self as delegate
self.locationService.startUpdatingLocation() // Requests start updating location
}
func didUpdateLocation() { // This will be called on location change
self.getWeatherForCurrentLocation()
}
func getWeatherForCurrentLocation() {
if let location = locationService.getCurrentLocation() {
//...
}
}
}