How do I create a new Swift project without using Storyboards?

Question

Creating a new project in XCode 6 doesn't allow to disable Storyboards. You can only select Swift or Objective-C and to use or not Core Data.

I tried deleting the storyboard and from the project removing the main storyboard and manually setting the window from didFinishLaunching

In the AppDelegate I have this:

class AppDelegate: UIResponder, UIApplicationDelegate {  var window: UIWindow var testNavigationController: UINavigationController      func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: NSDictionary?) -> Bool {          testNavigationController = UINavigationController()         var testViewController: UIViewController = UIViewController()         self.testNavigationController.pushViewController(testViewController, animated: false)          self.window = UIWindow(frame: UIScreen.mainScreen().bounds)          self.window.rootViewController = testNavigationController          self.window.backgroundColor = UIColor.whiteColor()          self.window.makeKeyAndVisible()          return true     } } 

However, XCode gives me an error:

Class 'AppDelegate' has no initializers

Anyone has succeed in this?

Answer 1

All it takes for not using Storyboards for the rootViewController:

1· Change AppDelegate.swift to:

import UIKit  @UIApplicationMain class AppDelegate: UIResponder, UIApplicationDelegate {      var window: UIWindow?      func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey : Any]? = nil) -> Bool {         window = UIWindow(frame: UIScreen.main.bounds)         if let window = window {             window.backgroundColor = UIColor.white             window.rootViewController = ViewController()             window.makeKeyAndVisible()         }         return true     } } 

2· Create a ViewController subclass of UIViewController:

import UIKit  class ViewController: UIViewController {      override func viewDidLoad() {         super.viewDidLoad()         view.backgroundColor = UIColor.blue     } } 

3· If you created the project from an Xcode template:

1. Remove the key-value pair for key "Main storyboard file base name" from Info.plist.
2. Delete the storyboard file Main.storyboard.

As you can see in the first code snippet, instead of implicitly unwrapping an optional, I rather like the if let syntax for unwrapping the optional window property. Here I'm using it like if let a = a { } so that the optional a becomes a non-optional reference inside the if-statement with the same name – a.

Finally self. is not necessary when referencing the window property inside it own class.

Answer 2

You must mark the window and testNavigationController variables as optional:

var window : UIWindow? var testNavigationController : UINavigationController? 

Swift classes require non-optional properties to be initialized during the instantiation:

Classes and structures must set all of their stored properties to an appropriate initial value by the time an instance of that class or structure is created. Stored properties cannot be left in an indeterminate state.

Properties of optional type are automatically initialized with a value of nil, indicating that the property is deliberately intended to have “no value yet” during initialization.

When using optional variables, remember to unwrap them with !, such as:

self.window!.backgroundColor = UIColor.whiteColor();