StackOverflow2013

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POselecting alternative first view controller from story board at application startup
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copied!<p>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 bumming me all night and I can't find an answer that "feels right".</p> <p>I'm writing an application that connects to a remote service and the users need to sign in before they can use it. When they start using the application, their first view should be the sign in dialog; when they've authenticated before, they immediately see the overview page.</p> <p>The project uses story boards - which I think is a great feature - so most of the code that selects and loads the root view controller is already taken care of. I thought the best place to add my logic is the <code>application:didFinishLaunchingWithOptions:</code> method of the <code>AppDelegate</code>:</p> <pre><code>- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions: (NSDictionary *)launchOptions { // select my root view controller here based on credentials present or not return YES; } </code></pre> <p>But this brought up two questions:</p> <ol> <li><p>Inside this particular delegate method, the root view controller has already been selected (and loaded?) based on the story board. Could I move to an earlier spot in the loading process to override the first view controller selection or would that needlessly complicate matters?</p></li> <li><p>To override the first view controller I need a reference to the story board, but I couldn't find a better way than to use the <code>storyboardWithName:bundle:</code> constructor of <code>UIStoryboard</code>. That feels wrong, the application should already have a reference to the story board, but how can I access it?</p></li> </ol> <p><strong>Update</strong></p> <p>I worked out the second issue I was having, as I found my answer here:</p> <p><a href="https://stackoverflow.com/questions/9853608/uistoryboard-whats-the-correctest-way-to-get-the-active-storyboard">UIStoryboard: What's the Correct Way to Get the Active Storyboard?</a></p> <pre><code>NSBundle *bundle = [NSBundle mainBundle]; NSString *sbFile = [bundle objectForInfoDictionaryKey:@"UIMainStoryboardFile"]; UIStoryboard *sb = [UIStoryboard storyboardWithName:sbFile bundle:bundle]; </code></pre> <p>The above will create a new story board instance; to get the active instance, it's a whole lot simpler:</p> <pre><code>UIStoryboard *sb = [[self.window rootViewController] storyboard]; </code></pre> <p>In the story board file itself you have to set an identifier for the view you wish to load, e.g. <code>LoginDialog</code>. Afterwards you instantiate the view like this:</p> <pre><code>LoginViewController *login = [sb instantiateViewControllerWithIdentifier:@"LoginDialog"]; [self.window setRootViewController:login]; </code></pre> <p>Within another view controller, the following suffices:</p> <pre><code>UIStoryboard *sb = self.storyboard; LoginViewController *login = [sb instantiateViewControllerWithIdentifier:@"LoginDialog"]; [self presentViewController:login animated:NO completion:nil]; </code></pre>

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