different initial viewcontroller - ios

Question

I'm building an app where the user can select a project from another ViewController and then open a split ViewController. I see that I can't set the other ViewController as initial, but I've come to with a secondary solution.
I set the split view as initial, and navigate to the fake initial ViewController on the viewDidAppear method as if it was initial. Then set the selected project in a global variable and close the project page like this:
[self dismissModalViewControllerAnimated:YES]
To open the splitview.
My question:
Can I use this approach? Will apple approve it if the app works as expected?
Thanks!
Edit:
This code is in my AppDelegate.m, what should it be changed to?
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
// Override point for customization after application launch.
UISplitViewController *splitviewController = (UISplitViewController *)self.window.rootViewController;
UINavigationController *navigationController = [splitviewController.viewControllers lastObject];
splitviewController.delegate = (id)navigationController.topViewController;
return YES;
}
Edit 2:
// Override point for customization after application launch.
UISplitViewController *splitviewController = (UISplitViewController *)self.window.rootViewController;
UINavigationController *navigationController = [splitviewController.viewControllers lastObject];
splitviewController.delegate = (id)navigationController.topViewController;
How do I reference the self.window.rootViewController to the SplitViewController? So that it doesn't think this viewcontroller will "host" the splitview?
Edit 3:
// Close the ProjectsViewController and open the selected project
[self presentViewController:_detailViewController animated:YES completion:^{
[[[[UIApplication sharedApplication] delegate] window] setRootViewController:_detailViewController];
}];
Edit 4:
* Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Application tried to present a Split View Controllers modally
method is linked with button:
-(void)selectedProject {
// The user opened a project
// Override point for customization after application launch.
UIStoryboard *mainStoryboard = [UIStoryboard storyboardWithName:#"Main" bundle:nil]; // assuming your split view controller in storyboard with name "Main" in project's main bundle
UIViewController *splitViewController = [mainStoryboard instantiateViewControllerWithIdentifier:#"splitVC"];
UISplitViewController *splitviewController = (UISplitViewController *)splitViewController;
UINavigationController *navigationController = [splitviewController.viewControllers lastObject];
splitviewController.delegate = (id)navigationController.topViewController;
// Close the ProjectsViewController and open the selected project
[self presentViewController:splitViewController animated:YES completion:^{
[[[[UIApplication sharedApplication] delegate] window] setRootViewController:splitViewController];
}];
}
Showing the projectsPage:
- (IBAction)closeProject:(id)sender {
// Show the selectSubjectBanner
_selectSubjectBanner.hidden = NO;
// Save the current subject in case the user edited it
[self saveCurrentSubject];
// Present the ProjectsViewController
[self performSegueWithIdentifier:#"projectsSegue" sender:nil];
}
}
closing the projectspage:
- (void)selectedProject {
// The user opened a project
UIStoryboard *mainStoryboard = [UIStoryboard storyboardWithName:#"Main" bundle:nil]; // assuming your split view controller in storyboard with name "Main" in project's main bundle
UISplitViewController *splitViewController = (UISplitViewController *)[mainStoryboard instantiateViewControllerWithIdentifier:#"splitVC"];
UINavigationController *navigationController = [splitViewController.viewControllers lastObject];
splitViewController.delegate = (id)navigationController.topViewController;
// Close the ProjectsViewController and open the selected project
[UIView transitionFromView:[[[[[UIApplication sharedApplication] delegate] window] rootViewController] view]
toView:splitViewController.view
duration:0.5
options:UIViewAnimationOptionTransitionFlipFromLeft
completion:^(BOOL finished) {
[[[[UIApplication sharedApplication] delegate] window] setRootViewController:splitViewController];
}];
}

Answer 1

better to set window's rootViewController
[[[[UIApplication sharedApplication] delegate] window]
setRootViewController:yourViewController];
Edit: Here is code how to instantiate view controller from storyboard,
UIStoryboard *mainStoryboard = [UIStoryboard storyboardWithName:#"Main" bundle:nil]; // assuming your split view controller in storyboard with name "Main" in project's main bundle
UIViewController *splitViewController = [mainStoryboard instantiateViewControllerWithIdentifier:#"splitVC"];
make sure you set Storyboard ID for your view controller in storyboard, Identity Inspector tab, splitVC(for example)
Edit: So, UISplitViewController is a container view controller itself, thus we can't hold it in UINavigationController, UITabBarController, add as childViewController, .. etc. And also we can't present it modally, thereby we don't get animated presentation. UISplitViewController should be the window's rootViewController. Simplest way to get animated transition between rootViewController and splitViewController is to use UIView's transitionFromView class method and visually swap their views, along changing rootViewController property. Here is your code edited.
- (void)selectedProject {
// The user opened a project
UIStoryboard *mainStoryboard = [UIStoryboard storyboardWithName:#"Main" bundle:nil]; // assuming your split view controller in storyboard with name "Main" in project's main bundle
UISplitViewController *splitViewController = (UISplitViewController *)[mainStoryboard instantiateViewControllerWithIdentifier:#"splitVC"];
UINavigationController *navigationController = [splitviewController.viewControllers lastObject];
splitViewController.delegate = (id)navigationController.topViewController;
// Close the ProjectsViewController and open the selected project
[UIView transitionFromView:[[[[[UIApplication sharedApplication] delegate] window] rootViewController] view]
toView:splitViewController.view
duration:0.5
options:UIViewAnimationOptionTransitionFlipFromLeft
completion:^(BOOL finished) {
[[[[UIApplication sharedApplication] delegate] window] setRootViewController:splitViewController];
}];
}

Answer 2

You can set any viewcontroller as your inital viewcontroller
You cannot launch a viewcontroller in viewDidAppear method. Thats bad.
Apple will not be rejecting app when considering the app transitions. It up to the developer.
You can set any viewcontroller on top by resetting the rootviewcontroller of window
Instead of storyboard check your logic and launch the necessary viewcontroller from appdelegate. Replace the window rootViewController respectively as mentioned by Seryozha