Swift - Is this code wrong or should I use UserDefaults? - ios

Question

I have an app which is connected to Firebase and you can login using Google and Facebook. The app has a home screen which is loaded when the user is signed in. I don't want to show the login screen if the user has already signed in before. So I use this code in the home screen to check if the user is signed in. Home screen is the initial view controller in the app
override func viewDidAppear(_ animated: Bool) {
if Auth.auth().currentUser != nil{
// user is signed in
}else{
// No user is signed in.
performSegue(withIdentifier: "login", sender: nil)
}
}
This code works very well. I know, that I could use UserDefaults too, but this seems to be an easier way. Is it wrong or should I use UserDefaults?
But the only problem with that is, for a quick moment the home screen is shown and then the segue is performed to the login screen, and I guess it's because it's in the viewdidApepar method, so the code gets executed after the viewcontroller appeared. Do you know a solution to it?

Answer 1

This is what I do personally, didFinishLaunchingWithOptions in AppDelegate.
if UserManager.sharedManager.currentUser != nil {
let appDelegate = UIApplication.shared.delegate as! AppDelegate
let storyboard = UIStoryboard(name: "Main", bundle: Bundle.main)
let viewController = storyboard.instantiateInitialViewController()
appDelegate.window?.rootViewController = viewController
} else {
let appDelegate = UIApplication.shared.delegate as! AppDelegate
let storyboard = UIStoryboard(name: "Login", bundle: Bundle.main)
let viewController = storyboard.instantiateInitialViewController()
appDelegate.window?.rootViewController = viewController
}
Of course I have a UserManager which handles if the user is logged in or not.(UserManager:NSObject)
var currentUser: User? {
return User.unarchiveStoredUser()
}
User is stored with decoder into UserDefautls then unarchived to verify if a user is logged in or not (User :NSObject)
func archiveUser() {
let data = NSKeyedArchiver.archivedData(withRootObject: self)
UserDefaults.standard.set(data, forKey: "userIdentifier")
UserDefaults.standard.synchronize()
}
class func unarchiveStoredUser() -> User? {
if let data = UserDefaults.standard.object(forKey: "userIdentifier") as? Data {
let user = NSKeyedUnarchiver.unarchiveObject(with: data) as! User
return user
}
return nil
}
Hope it helps you.