Programmatic layout in iOS 13

README.md

You sometimes need to have a programmatic layout when making iOS apps. But, if you have been playing around with the Xcode beta, you might notice that your old code to do that doesn't work. This code is used in the func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) in SceneDelegate.swift to initialize the programmatic layout. There is also a Storyboard name in the Info.plist you have to delete. Happy coding!

SceneDelegate.swift

//Stuff before here (not neccesary for this gist)    
func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {
      
    guard let windowScene = scene as? UIWindowScene else {
      fatalError("Could not cast scene to UIWindowScene.")
    }
    let window = UIWindow(windowScene: windowScene)
    window.rootViewController = UIViewController()
    self.window = window
    window.makeKeyAndVisible()
}
//Stuff after here (not neccesary for this gist)    

Thanks for sharing this! I modified slightly to reflect the fact that operation can't continue in the unlikely event that the windowScene cast fails.

  func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {
    guard let windowScene = scene as? UIWindowScene else {
      fatalError("Could not cast scene to UIWindowScene.")
    }
    let window = UIWindow(windowScene: windowScene)
    window.rootViewController = UIViewController()
    self.window = window
    window.makeKeyAndVisible()
  }

I like the fail-early approach because it documents my expectations of behavior, and the decreased indentation helps readability.

If you're interested in my approach to programmatic layout, here is a whole tutorial: https://racecondition.software/blog/programmatic-layout/

I need to update the tutorial with a variant of your gist.

Updated!