Googlemaps not allowing me to locate the users location? - swift

Question

I am trying to create a view controller on swift that shows where the user is located. I have already implemented google maps, so now all I have to do is plug in the correct code. When doing so, I keep getting these two error messages then the app crashes. Can someone help me with figuring out a solution> any and all help is appreciated.
import UIKit
import Foundation
import Firebase
import MapKit
import GoogleMaps
import CoreLocation
class mainViewController: UIViewController, MKMapViewDelegate, CLLocationManagerDelegate {
let defaults = UserDefaults.standard
let locationManager = CLLocationManager()
var mapView = GMSMapView()
var camera = GMSCameraPosition()
override func viewDidLoad() {
super.viewDidLoad()
self.locationManager.delegate = self
self.locationManager.desiredAccuracy = kCLLocationAccuracyBest
self.locationManager.requestWhenInUseAuthorization()
self.locationManager.startUpdatingLocation()
GMSServices.provideAPIKey("AIzaSyBDOLisA3c-wDTbkbSssAxEb3iLw7Y5vHo")
let camera = GMSCameraPosition.camera(withLatitude: (self.locationManager.location?.coordinate.latitude)!, longitude: (self.locationManager.location?.coordinate.latitude)!, zoom: 17)
let mapView = GMSMapView.map(withFrame: CGRect.zero, camera: camera)
view = mapView
let marker = GMSMarker()
marker.position = CLLocationCoordinate2D(latitude: (self.locationManager.location?.coordinate.latitude)!, longitude: (self.locationManager.location?.coordinate.latitude)!)
marker.snippet = "Current Location"
marker.map = mapView
self.mapView.addSubview(mapView)
view.backgroundColor = GREEN_Theme
navigationController?.navigationBar.prefersLargeTitles = true
navigationItem.title = "Welcome"
navigationItem.rightBarButtonItem = UIBarButtonItem(title: "Logout", style: .plain, target: self, action: #selector(Logout))
}
#objc func Logout() {
print("Logged Out")
do {
// I am receiving this error message on the auth.auth().signOut() "Use of unresolved identifier 'Auth'"
try Auth.auth().signOut()
defaults.set(false, forKey: "user is logged in")
let loginController = UINavigationController(rootViewController: LoginController())
present(loginController, animated: true, completion: nil)
} catch let err {
print(err.localizedDescription)
}
}
}

Answer 1

Your issue is that the CLLocationManager does not have enough time to fetch the info and in the meantime other functions ask for that info which its still nil.
The below will take care the issue, it also stops updating the locations all the time which can be battery draining especially considering that you have set AccuracyBest.
func getLocation(){
locationManager=CLLocationManager()
locationManager.delegate = self
locationManager.desiredAccuracy = kCLLocationAccuracyBest
locationManager.requestWhenInUseAuthorization()
locationManager.startUpdatingLocation()
}
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]){
let lastLocation=locations[locations.count-1]
if lastLocation.horizontalAccuracy>0{
locationManager.stopUpdatingLocation()
let latitude = lastLocation.coordinate.latitude
let longitude = lastLocation.coordinate.longitude
GMSServices.provideAPIKey("AIzaSyBDOLisA3c-wDTbkbSssAxEb3iLw7Y5vHo")
// everything that is going to require the latitude and longitude from the location manager goes here
let camera = GMSCameraPosition.camera(withLatitude: (self.locationManager.location?.coordinate.latitude)!, longitude: (self.locationManager.location?.coordinate.latitude)!, zoom: 17)
let mapView = GMSMapView.map(withFrame: CGRect.zero, camera: camera)
self.view = mapView
let marker = GMSMarker()
marker.position = CLLocationCoordinate2D(latitude: (self.locationManager.location?.coordinate.latitude)!, longitude: (self.locationManager.location?.coordinate.latitude)!)
marker.snippet = "Current Location"
marker.map = mapView
self.mapView.addSubview(mapView)
}
}
Your viewDidLoad should have:
override func viewDidLoad() {
super.viewDidLoad()
getLocation()
view.backgroundColor = GREEN_Theme
navigationController?.navigationBar.prefersLargeTitles = true
navigationItem.title = "Welcome"
navigationItem.rightBarButtonItem = UIBarButtonItem(title: "Logout", style: .plain, target: self, action: #selector(Logout))
}

Answer 2

You are using Google Map as your map view, which means that you create an instance of the GMSMapView class. That's an object. You have one. And I assume that it's IBOutlet-wired. It comes with several delegate methods. So you may want to set its delegate. And you want your view controller to receive data from GMSMapView. So you set the delegate of that class to self (your view controller).
import UIKit
import Foundation
import Firebase
import GoogleMaps
import CoreLocation
class mainViewController: UIViewController, CLLocationManagerDelegate, GMSMapViewDelegate {
// MARK: - Instance variables
private let locationManager = CLLocationManager()
// MARK: - IBOutlets
#IBOutlet weak var mapView: GMSMapView!
// MARK: - IBActions
// MARK: - Life cycle
override func viewDidLoad() {
super.viewDidLoad()
mapView.delegate = self
mapView.isMyLocationEnabled = true
}
// MARK: - Life cycle
// MARK: - GMSMapView delegate methods
func mapView(_ mapView: GMSMapView, idleAt position: GMSCameraPosition) {
reverseGeocodeCoordinate(position.target) // sending data when the mapView is not moved or pinched by the finger //
}
func reverseGeocodeCoordinate(_ coordinate: CLLocationCoordinate2D) {
let geocoder = GMSGeocoder()
geocoder.reverseGeocodeCoordinate(coordinate) { response, error in
guard let address = response?.firstResult(), let lines = address.lines else {
return
}
...
...
}
}
}