Hello. In Xcode 11 I have to separate files AppDelegate.swift and SceneDelegate.swift. In which of them I should put the code explained in this chapter?
var window: UIWindow?
let dataModel = DataModel()
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
let navigationController = window!.rootViewController as! UINavigationController
let controller = navigationController.viewControllers[0] as! AllListsViewController
controller.dataModel = dataModel
return true
}
saveData()
However, in iOS 13, window will be returned as nil, due to the UIScene additions. I had that problem with the Checklists app, and MyLocations app, and had to change my target to iOS 12, and remove the SceneDelegate.swift file, remove the UISceneSession code in AppDelegate.swift, and modify Info.plist to work.
You put the code in this section in the SceneDelegate method :
func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {
// Use this method to optionally configure and attach the UIWindow `window` to the provided UIWindowScene `scene`.
// If using a storyboard, the `window` property will automatically be initialized and attached to the scene.
// This delegate does not imply the connecting scene or session are new (see `application:configurationForConnectingSceneSession` instead).
let navigationController = window!.rootViewController as! UINavigationController
let controller = navigationController.viewControllers[0] as! AllListViewController
controller.dataModel = dataModel
guard let _ = (scene as? UIWindowScene) else { return }
}
I tried this code, but saving not works. All data dissapears when I reload the app. Also I tried to run original project from materials chapters, but also saving data not works.
import UIKit
class SceneDelegate: UIResponder, UIWindowSceneDelegate {
var window: UIWindow?
let dataModel = DataModel()
func saveData() {
dataModel.saveChecklists()
}
func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {
// Use this method to optionally configure and attach the UIWindow `window` to the provided UIWindowScene `scene`.
// If using a storyboard, the `window` property will automatically be initialized and attached to the scene.
// This delegate does not imply the connecting scene or session are new (see `application:configurationForConnectingSceneSession` instead).
let navigationController = window!.rootViewController as! UINavigationController
let controller = navigationController.viewControllers[0] as! AllListsViewController
controller.dataModel = dataModel
guard let _ = (scene as? UIWindowScene) else { return }
}
func sceneDidDisconnect(_ scene: UIScene) {
// Called as the scene is being released by the system.
// This occurs shortly after the scene enters the background, or when its session is discarded.
// Release any resources associated with this scene that can be re-created the next time the scene connects.
// The scene may re-connect later, as its session was not neccessarily discarded (see `application:didDiscardSceneSessions` instead).
saveData()
}
func sceneDidBecomeActive(_ scene: UIScene) {
// Called when the scene has moved from an inactive state to an active state.
// Use this method to restart any tasks that were paused (or not yet started) when the scene was inactive.
}
func sceneWillResignActive(_ scene: UIScene) {
// Called when the scene will move from an active state to an inactive state.
// This may occur due to temporary interruptions (ex. an incoming phone call).
}
func sceneWillEnterForeground(_ scene: UIScene) {
// Called as the scene transitions from the background to the foreground.
// Use this method to undo the changes made on entering the background.
}
func sceneDidEnterBackground(_ scene: UIScene) {
// Called as the scene transitions from the foreground to the background.
// Use this method to save data, release shared resources, and store enough scene-specific state information
// to restore the scene back to its current state.
// Save changes in the application's managed object context when the application transitions to the background.
saveData()
}
}
Thanks you guys so much