Passing data from Scene Delegate to ViewController when opening app with URL - swift

Question

I need to Show a View on my initial controller and set a UILabel when the app launches through URL Dynamic Link during Firebase Email Verification.
Problem I'm having is the label is not initialised so app crashes during the process. I have tried many approaches but can't get it to show my view and set the label when opening a Dynamic Link, even when the App is already open.
Scene Delegate
func scene(_ scene: UIScene, continue userActivity: NSUserActivity) {
if let link = userActivity.webpageURL?.absoluteString
{
if Auth.auth().isSignIn(withEmailLink: link) {
Config().verifyEmail(link: link)
}
}
}
AppDelegate
#main
class AppDelegate: UIResponder, UIApplicationDelegate {
var errorText: String?
var errorType: Bool?
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
FirebaseApp.configure()
return true
}
ViewController
func loadErrorInfo()
{
let appDelegate = UIApplication.shared.delegate as! AppDelegate
if let eText = appDelegate.errorText, let eType = appDelegate.errorType {
errorCall(message: eText, error: eType)
} else {
errorBox.isHidden = true
}
}
func errorCall(message: String, error: Bool)
{
if error {
self.errorLabel.textColor = UIColor.yellow
self.errorLabel.text = message
self.errorBox.isHidden = false
self.errorBox.shake()
} else {
self.errorLabel.textColor = UIColor.white
self.errorLabel.text = message
self.errorBox.isHidden = false
self.errorBox.shakeL()
}
}
Custom Config NSObject Class
import UIKit
import FirebaseAuth
open class Config: NSObject {
public func verifyEmail(link: String)
{
var email = ""; var password = ""
if let x = UserDefaults.standard.object(forKey: "Email") as? String { email = x }
if let y = UserDefaults.standard.object(forKey: "Password-\(email)") as? String { password = y }
if password != "" && email != ""
{
Auth.auth().signIn(withEmail: email, link: link) { (user, error) in
if let use = user, error == nil
{
Auth.auth().currentUser?.updatePassword(to: password) { (error) in
if let error = error
{
print(error)
let appDelegate = UIApplication.shared.delegate as! AppDelegate
appDelegate.errorText = error.localizedDescription
appDelegate.errorType = true
ViewController().loadErrorInfo()
}
else
{
print(use, "Logged In")
let appDelegate = UIApplication.shared.delegate as! AppDelegate
appDelegate.errorText = "\(use) Logged In"
appDelegate.errorType = false
ViewController().loadErrorInfo()
}
}
}
}
}
}
}
Not sure what other method will work. To summarise, after clicking a Dynamic Link in an Email, I want to Change my UILabel on main ViewController which is an initial controller. At the moment every approach causes it to crash as the UILabel is not Set, even if the controller is already initialised.

Answer 1

Managed to fix it by initialising the controller again and updating the root controller.
// SceneDelegate
func changeRootViewController(_ vc: UIViewController, animated: Bool = true)
{
guard let window = self.window else {
return
}
window.rootViewController = vc
}
//Reinitialise
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let destinationNavigationController = storyboard.instantiateViewController(withIdentifier: "ViewController2")
(UIApplication.shared.connectedScenes.first?.delegate as? SceneDelegate)?.changeRootViewController(destinationNavigationController)