selecting alternative first view controller from story board at application startup

Question

I\'ve just started on iOS programming and so far the tutorials and answers I found here have been a great help to move forward. However, this particular problem has been bum

Answer 1

With the main storyboard already loaded, it's just a matter of finding its reference so that I can instantiate another root view controller:

UIStoryboard *mainStoryboard = self.window.rootViewController.storyboard;

self.window.rootViewController = [mainStoryboard 
    instantiateViewControllerWithIdentifier:@"view-controller-id"];

Answer 2

You can just reset the root view controller of the window

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:
      (NSDictionary *)launchOptions
{
   if(your_condition) {
       UIViewController *newRoot = [your implementation];
       self.window.rootViewController = newRoot;
   }
   return YES;
}

This is worked for me, Xcode5.0.1

Answer 3

I had hardly used storyboard & probably this is not the exact answer to your question. But I will suggest you some way what I did in my project created without using a storyboard.

In didFinishLaunchingWithOptions AuthenticationViewController is the first view loaded. It asks login credentials. Once entered it will enter the actual ViewControllers(viz. TabBar &all..) used by project.

Interesting feature added to project is, when you enter credentials I popped up an UIAleretView that asks user to choose one of the three options.

1. Save Credentials without passcode
2. Save Credentials with passcode
3. Dont save credentials

Here pass code is nothing but 4digit number entered by user. Whenever he wants to 'Save Credentials with passcode', I pushViewController that shows NumberPad instad of default keyboard & popviewController when it finishes entering of pin. If user 'Dont save credentials' & later on while playing the app wants to go for other authentication options then I added the last tab of TabBarController as 'Settings' tab inside which I allow user to choose one of the Authentication options, popped as UIAlertView in the beginning of app start after login.

Dont forget to Save credentials in keychain

In a nutshell,

1. AuthenticationViewController-> check if login credentials are stored in keychain

1.1. If not stored(i.e. 3. Dont save credentials)-> then show Login page.

1.2. If credentials are saved in keychain-> extract them & see if it is tied with passcode.

1.2.1. If it is tied with passcode(i.e. 2. Save Credentials with passcode )-> then show passcode page.

1.2.2. If it is not tied (1. Save Credentials without passcode)-> then show/load you project's TabBarController hierarchy or other stuff. here actually your app start.

Answer 4

I have a similar scenario as yours. My application uses a UINavigationController as the root view controller. If the user is logged in, I want to present him/her with NotLoggedInViewController, while if it's logged in I want to show the LoggedInViewController.

In a storyboard a UINavigationController can only have one child, so you have to be able to programmatically assign another root view controller to it.

I start by creating a custom navigation controller class, let's name it MyNavigationController. In the storyboard I assign this custom class to the navigation controller object.

Still in the storyboard, I then model both view controllers, and connect one of them to the navigation controller object. Since I need to be able to access them from my code later on, I assign each of them an identifier using the XCode inspector on the right. These identifiers which can be arbitrary strings, but to things simple I just use the class names.

Finally I then implement the viewDidLoad method on MyNavigationController class:

BOOL isLoggedIn = ...;

- (void)viewDidLoad {
  id rootController;
  if (isLoggedIn) {
    rootController = [self.storyboard instantiateViewControllerWithIdentifier:@"LoggedInViewController"];
  } else {
    rootController = [self.storyboard instantiateViewControllerWithIdentifier:@"NotLoggedInViewController"];
  }
  self.viewControllers = [NSArray arrayWithObjects:rootController, nil];
}