Redirect to RootViewController ios

Question

Im modifying an older ios app which has the mainscreen setup through :

self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
rootViewController = [UITabBarController new];
self.window.rootViewController = rootViewController;
[self.window makeKeyAndVisible];
[self setup];

How can i programatically redirect back to that screen? Im adding a login screen and need to know how to redirect after successful login.

Thanks

Answer 1

#define kUserAuthChangedNotification  @"kUserAuthStatusChanged"
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    [self changeRootControllerWithIsUserSignIn:NO];//You must send user sign in or not
    [self.window makeKeyAndVisible];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(userAuthStatusChanged) name:kUserAuthChangedNotification object:nil];
}

#pragma mark helper methods

- (void)userAuthStatusChanged {
    [self changeRootControllerWithIsUserSignIn:YES];//You must send user sign in or not
}

- (void)changeRootControllerWithIsUserSignIn:(BOOL)isSignIn {
    if(isSignIn){ 
        rootViewController = [UITabBarController new];
        self.window.rootViewController = rootViewController;
        [self setup];
    } else {
        YourLoginViewController * ctrl = [YourLoginViewController new];
        self.window.rootViewController = ctrl;
    }
}

When successful login Or log out you must call:

[[NSNotificationCenter defaultCenter] postNotificationName:kUserAuthChangedNotification object:nil];