Changing "initWithNibName" to "storyboardWithName" - ios

Question

I followed some tutorial to create an open doors animation during the app launch but it's calling an
xib file and I want to call storyboard and I don' have enough experience with this.
Here's my code
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];
// Override point for customization after application launch.
self.viewController = [[[OpenDoorsViewController alloc] initWithNibName:#"OpenDoorsViewController" bundle:nil] autorelease];
self.window.rootViewController = self.viewController;
[self.window makeKeyAndVisible];
return YES;
}

Answer 1

If you simply want to load the initial view controller of the storyboard when the app launches, just return YES in application:didFinishLaunchingWithOptions:.
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
return YES;
}
If you want to load a specific controller from the storyboard, you need to first get the storybard instance by
UIStoryboard * storyboard = [UIStoryboard storyboardWithName:#"StoryboardName" bundle:nil];
then use it to instantiate the controller you need
UIViewController * controller = [storyboard instantiateViewControllerWithIdentifier:#"controllerIdentifier"];
where controllerIdentifier has been assigned as storyboard identifier to the controller in Interface Builder.
Here's an example loading a specific view controller, presenting it at launch.
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
UIStoryboard * storyboard = [UIStoryboard storyboardWithName:#"StoryboardName" bundle:nil];
UIViewController * controller = [storyboard instantiateViewControllerWithIdentifier:#"controllerIdentifier"];
self.window.rootViewController = controller;
return YES;
}

Answer 2

If you start a new iOS project and select 'Use storyboards', the Storyboard will be automatically preloaded for you.
Storyboard is a place with all the controllers (scenes) of your app, and to reference one, you'll need to use
UIViewController *controller = [[UIStoryboard storyboardWithName:#"storyboard" bundle:[NSBundle mainBundle]] instantiateViewControllerWithIdentifier:#"an identifier"];