CODEWITHSUNDEEP
iosswiftuikitpresentviewcontroller
Ian Warburton
Ian Warburton

Reputation: 15666

View controller added in app delegate not appearing

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {

    let storyBoard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)

    let auth: UIViewController =
        storyBoard.instantiateViewController(withIdentifier: "Auth") as UIViewController

    window?.rootViewController?.present(auth, animated: true, completion: nil)

    return true
}

I get the error...

Warning: Attempt to present on whose view is not in the window hierarchy!

I presume the root controller has not been properly configured at this point in the app life cycle.

How do I do this? I want to avoid having the root controller having to check whether it needs to show the login screen.

Upvotes: 0

Views: 491

Answers (2)

Taras Chernyshenko
Taras Chernyshenko

Reputation: 2829

You can do it like that:

func application(_ application: UIApplication,
    didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
    if Settings.appSettings.authToken != nil {
        self.showMainController()
    }
    NotificationCenter.default.addObserver(forName: .authorizationOperationDidSuccess,
        object: nil, queue: nil) { (notification) in
        self.showMainController()
    }

    return true
}

private func showMainController() {
    let storyBoard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)

    let controller: UIViewController =
        storyBoard.instantiateViewController(withIdentifier: "Main") as UIViewController
    if self.window == nil {
        self.window = UIWindow(frame: UIScreen.main.bounds)
    }
    self.window?.backgroundColor = UIColor.white
    self.window?.rootViewController = controller
    self.window?.makeKeyAndVisible()
}

private func showAuthorizationController() {
        let storyBoard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)

    let controller: UIViewController =
        storyBoard.instantiateViewController(withIdentifier: "Auth") as UIViewController
    if self.window == nil {
        self.window = UIWindow(frame: UIScreen.main.bounds)
    }
    self.window?.backgroundColor = UIColor.white
    self.window?.rootViewController = controller
    self.window?.makeKeyAndVisible()
}

On successful login make

NotificationCenter.default.post(name: .authorizationOperationDidSuccess,
                    object: nil)

Upvotes: 1

dahiya_boy
dahiya_boy

Reputation: 9503

Make change here,

let auth: AuthVC =  storyBoard.instantiateViewController(withIdentifier: "Auth") as AuthVC

// AuthVC is your_VC_name

Still facing issue, you can ask.

Upvotes: 0

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