View_Controllers
View Controllers
Creation
Different types of View controller can be utilized. We would initialize view controller using storyboard and setting the controller in the inspector.
The parent view will perform a segue and call upon the storyboard using Storyboard references and storyboard name.
Present
This would be better explained using iOS Segues doc as we would dive more deep into that doc about creating segues and linking them differently.
Dismiss
Dismissing Child view controller could be done using various methods depending on how it was created.
View Controller
Normal View controller uses just dismiss method.
self.dismiss(animated: true, completion: nil)
Navigation Controller
navigationController?.dismiss(animated: true)
Pop
Navigation controller needs pop method to pop the current view controller into the navigation stack
navigationController?.popViewController(animated: true)
We can also dismiss the the whole
Presentation iOS 13
Different styles Medium article
Init
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
}
https://stackoverflow.com/questions/24036393/fatal-error-use-of-unimplemented-initializer-initcoder-for-class
Container Child View
https://cocoacasts.com/managing-view-controllers-with-container-view-controllers/
https://guides.codepath.com/ios/Adding-and-Removing-Child-View-Controllers
No Storyboard Xcode
No main.storyboard in new project
Basically remove its references and just create a new ViewController() instance and set its view to rootView
Depending on whether your app uses AppDelegate or SceneDelegate
AppDelegate
var window: UIWindow?
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
let window = UIWindow(frame: UIScreen.main.bounds)
window.rootViewController = ViewController()
window.makeKeyAndVisible()
self.window = window
return true
}
SceneDelegate
func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {
guard let windowScene = (scene as? UIWindowScene) else { return }
let window = UIWindow(windowScene: windowScene) window.rootViewController = ViewController()
window.makeKeyAndVisible()
self.window = window
}
https://sarunw.com/posts/how-to-create-new-xcode-project-without-storyboard/
Errors
Warning: Attempt to present * on *whose view is not in the window hierarchy"
This could be because there is timing issue when presenting the view controller.
So it is safe to do this after some event has happened via a button or a delay.
override func viewDidAppear(_ animated: Bool) {
    initializeAnotherView()
}
But to be extra sure you can present another screen after the ViewLifecycle method named viewDidAppear() is called and then try to present that view controller.
Resources
My own uiViewController UI specific documentation changes.
Custom Presentation Controllers