mapView: GMSMapView! nil causing the app to crash (swift) - ios

Question

I'm completely new when it comes to use Google Maps SKD for iOS and I have the following problem: My app uses Firebase and the MapVC is the first VC if the user is logged in. I set a UIVIew in the storyboard with the size I wanted and made its class GMSMapView. I also use the CLLocation Manager and the location comes ok, I pass it on to the camera variable and it's fine. But if add this code: mapView = GMSMapView.map(withFrame: CGRect.zero, camera: camera) or this code: self.mapView.camera = camera the app crashes because mapView is nil. If I don't add those lines of code, the map shown is just the default map (Europe). What I need is the map camera to show the location I'm getting from CLLocation and updates it on the map as the location changes as well.
My code for the MapVC is below:
import UIKit
import GoogleMaps
import GooglePlaces
import CoreLocation
import Alamofire
import Firebase
import FirebaseFirestore
class AlertaVC: UIViewController, CLLocationManagerDelegate {
#IBOutlet weak var alertaBtn: RoundButton!
var latitude: CLLocationSpeed?
var longitude: CLLocationDegrees?
var mapView: GoogleMaps.GMSMapView!
var db: Firestore!
var userID: String?
var nameUser: Any?
let locationManager = CLLocationManager()
#IBAction func dispararAlertaBtn(_ sender: UIButton) {
//changing the title and color after the alert is sent
alertaBtn.isSelected = !alertaBtn.isSelected
if alertaBtn.isSelected {
//setting up twilio to send the alert SMS
let headers: HTTPHeaders = [
"Content-Type": "application/x-www-form-urlencoded"
]
//add the phone numbers from the firebase document
let parameters: Parameters = [
"To": "phone-number",
"Body": "Ola, to enviando SMS!"
]
//change the SMS body to include the user's name and the link with live location
AF.request("https://url.twil.io/smsAlerta", method: .post, parameters: parameters, headers: headers).responseJSON { response in
print(response.response as Any, "response alamofire")
}
alertaBtn.setTitle("Encerrar alerta!", for: .normal)
alertaBtn.backgroundColor = UIColor(red: 0.83529, green: 0.4, blue: 0.5725490196, alpha: 1.0)
} else {
alertaBtn.setTitle("Disparar alerta!", for: .normal)
alertaBtn.backgroundColor = UIColor(red: 0.3254, green: 0.1921, blue: 0.2627, alpha: 1.0)
}
}
override func viewDidLoad() {
super.viewDidLoad()
locationManager.requestAlwaysAuthorization()
locationManager.requestWhenInUseAuthorization()
if CLLocationManager.locationServicesEnabled() {
locationManager.delegate = self
locationManager.desiredAccuracy = kCLLocationAccuracyNearestTenMeters
locationManager.startUpdatingLocation()
}
db = Firestore.firestore()
let user = Auth.auth().currentUser
if let user = user {
// The user's ID, unique to the Firebase project.
self.userID = user.uid
print(self.userID!, "user ID firebase")
}
}
override func viewWillAppear(_ animated: Bool) {
//showCurrentLocation() Tried calling the function #ViewWillAppear but it didn't work either
}
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
guard let locValue: CLLocationCoordinate2D = manager.location?.coordinate else { return }
latitude = locValue.latitude
longitude = locValue.longitude
let camera: GMSCameraPosition = GMSCameraPosition.camera(withLatitude: latitude ?? 19.741755, longitude: longitude ?? -155.844437, zoom: 7.0) //if doesnt load will show Hawaii
print(camera as Any, "camera") <-- WORKS FINE: GMSCameraPosition 0x600000f389f0: target:(37.332, -122.031) bearing:0.000 zoomLevel:7.000 viewingAngle:0.000 camera
self.mapView.camera = camera <<--- CRASHES HERE: Fatal error: Unexpectedly found nil while implicitly unwrapping an Optional value
self.mapView?.animate(to: camera) <<-- WITHOUT THE LINE ABOVE THIS ANIMATION DOESN`T HAPPEN, BECAUSE MAPVIEW IS NIL
print("locations = \(latitude ?? 56.56), \(longitude ?? 45.45)")
}
func showCurrentLocation() { <<- NOT BEING CALLED, BUT IF IT IS, CRASHES
//mapView.settings.myLocationButton = true
let locationObj = locationManager.location!
let coord = locationObj.coordinate
let lattitude = coord.latitude
let longitude = coord.longitude
print(" lat in updating \(lattitude) ")
print(" long in updating \(longitude)")
let center = CLLocationCoordinate2D(latitude: locationObj.coordinate.latitude, longitude: locationObj.coordinate.longitude)
let marker = GMSMarker()
marker.position = center
marker.title = "current location"
marker.map = mapView
let camera: GMSCameraPosition = GMSCameraPosition.camera(withLatitude: lattitude, longitude: longitude, zoom: 7.0)
mapView = GMSMapView.map(withFrame: CGRect.zero, camera: camera) <-- CRASHES HERE
self.mapView.animate(to: camera)
}
func fetchUserName(userId: String) {
db.collection("Usuarias").document(self.userID!).getDocument() {
(document, err) in
if let document = document, document.exists {
let dataDescription = document.data()!["Nome"] ?? "nil"
print("Document data: \(dataDescription)")
self.nameUser = dataDescription
print(self.nameUser as Any, "dentro do fetch")
} else {
print("Document does not exist")
}
}
}
}
I'd appreciate any help. Thanks =)

Answer 1

If you've created the 'View' in storyboard and assign as 'GMSMapView' you should add it as 'IBOutlet' in ViewController, you can do it by clicking 'Option' on keyboard and drag from map to ViewController like you've add 'alertaBtn', if you want to create map programmatically you need to initiate it in 'viewDidLoad' method then use it to set camera or to do other changes.