iOS - Transition between different Storyboard view controllers - ios

Question

I have divided my project into two storyboards:
Main.storyboard - For authenticated user. Also this is the default storyboard.
Login.storyboard - For non-authenticated user.
App delegate file:
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
if(user is authenticated)
{
[self presentLoginScreen:YES];
return YES;
}
Login Screen in app delegate file:
-(void)presentLoginScreen:(BOOL)animated{
UIStoryboard *storyboard = [UIStoryboard storyboardWithName:#"Login" bundle:[NSBundle mainBundle]];
UIViewController *vc =[storyboard instantiateInitialViewController];
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
self.window.rootViewController = vc;
}
On logout, login Screen is presented. I defined this in app delegate file:
-(void)logOut{
//clear data
UIStoryboard *storyboard = [UIStoryboard storyboardWithName:#"Login" bundle:[NSBundle mainBundle]];
UIViewController *vc =[storyboard instantiateInitialViewController];
self.window.rootViewController = vc;
//Show login Screen
[self presentLoginScreen:NO];
}
From viewcontroller of MainStoryBoard(letsay mainstoryboardVc.m), logOut is called as:
-(void)didTouchLogOut{
NSLog(#"GoodBye");
AppDelegate *appDelegateTemp = [[UIApplication sharedApplication]delegate];
[appDelegateTemp logOut];
}
This is causing a lot of issue:
Firstly, when I log out, and move to login screen, I can still see mainstoryboardVc.m in the background which looks very clumsy.
I log out, re-log in and again trying to log out, I see following message:
Presenting view controllers on detached view controllers is discouraged
and login screen is not presented.
I tried many answers on the web on view controller presentations between two storyboards without keeping history, nothing seems to work...

Answer 1

To swap out UIViewControllers there are a few other methods that need to be called when transitioning the root view controller:
Objective-c:
- (void)setRootViewController:(UIViewController *) newRootViewController {
UIViewController* currentViewController = self.window.rootViewController;
if (newRootViewController != currentViewController) {
[currentViewController willMoveToParentViewController:nil];
[currentViewController.view removeFromSuperview];
[currentViewController removeFromParentViewController];
self.window.rootViewController = newRootViewController;
}
}
Swift:
func setRootViewController(newRootViewController: UIViewController) {
if let currentViewController = self.window?.rootViewController {
if currentViewController != newRootViewController {
currentViewController.willMoveToParentViewController(nil)
currentViewController.view.removeFromSuperview()
currentViewController.removeFromParentViewController()
self.window?.rootViewController = currentViewController
}
}
}

Answer 2

Two UIViewController objects are duplicated because you set self.window.rootViewController for both of them. Try that;
Login
-(void)presentLoginScreen:(BOOL)animated{
UIStoryboard *storyboard = [UIStoryboard storyboardWithName:#"Login" bundle:[NSBundle mainBundle]];
UIViewController *vc =[storyboard instantiateInitialViewController];
self.window.rootViewController = vc;
[self.window makeKeyAndVisible];
}
Logout
-(void)logOut{
UIStoryboard *storyboard = [UIStoryboard storyboardWithName:#"Login" bundle:[NSBundle mainBundle]];
UIViewController *vc =[storyboard instantiateInitialViewController];
[self presentViewController:vc animated:YES completion:nil];
}