How do I dismiss a rootViewController before presenting a new UITabBarController?

Question

I\'ve set up a UIViewController as my rootViewController in AppDelegate, however, when a user logs in or skips it I am presenting a UITabBarController over the top.

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Answer 1

It's too easy to maintain condition for user logged in or not, and then based on that status. You can navigate to your view.

You can try this way :

1.In AppDelegate you can these methods.

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
    // Override point for customization after application launch.

    let isLogin = UserDefaults.standard.bool(forKey: "IS_LOGIN")
    if isLogin == true {
        self.goToDashboardView()
    } else {
        self.goToLoginView()
    }
    return true
}

//MARK:- ------- Global Methods -------

class func sharedInstance() -> AppDelegate {
    return UIApplication.shared.delegate as! AppDelegate
}

func goToLoginView() {

    let sb = UIStoryboard.init(name: "Main", bundle: nil)
    let loginVC = sb.instantiateViewController(withIdentifier: "LoginViewController") as! LoginViewController
    let navVC = UINavigationController(rootViewController: loginVC) // You can skip this if you do not want to add navigation bar
    self.window?.rootViewController = navVC // if you skipped above line, then you have to assign 'loginVC' here.
    self.window?.makeKeyAndVisible()
}

func goToDashboardView() {

    let sb = UIStoryboard.init(name: "Main", bundle: nil)
    let tabbarVC = sb.instantiateViewController(withIdentifier: "MyTabBarController") as! MyTabBarController
    self).window?.rootViewController = tabbarVC // if you skipped above line, then you have to assign 'loginVC' here.
    self.window?.makeKeyAndVisible()
}

2.In LoginViewController, when user logged in successfully.

@IBAction func btnLoginClicked(_ sender: UIButton) {

    // Your API call or other code
    // If all things goes well, then login and go to dashboard

    UserDefaults.standard.set(true, forKey: "IS_LOGIN")
    AppDelegate.sharedInstance().goToDashboardView()
}

3.And finally, whenever and from wherever you want to log out from app, just call below code.

@IBAction func btnLogOutClicked(_ sender: UIButton) {

    // Your API call or other code
    // If all things goes well, then logout and go to login view

    UserDefaults.standard.set(false, forKey: "IS_LOGIN")
    AppDelegate.sharedInstance().goToLoginView()
}

4.And Main.storyboard should have design something like :

Answer 2

you do not need to present the UITabBarViewController and then dismiss the LoginViewController, you just need to reset the UITabBarViewController as a rootViewController for you app after login or skip as the following:

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
self.window = UIWindow(frame: UIScreen.mainScreen().bounds)

// Override point for customization after application launch.

let yourTabBar = UIStoryboard(name: "YOUR_STORYBOARD_NAME", bundle: nil).instantiateViewController(withIdentifier: "YOUR_UITABBARCONTROLLER_ID")
self.window!.rootViewController = yourTabBar
self.window!.makeKeyAndVisible()
return true
}

Answer 3

you can design your code like this.

This one