How to dismiss current view controller from app delegate in swift? - ios

Question

I want to pop current view controller on some condition from appDelegate but I don't know how to do so, if any idea please help me out...................................................................................
import UIKit
import IQKeyboardManagerSwift
let kSharedAppDelegate = UIApplication.shared.delegate as? AppDelegate
#UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
var window: UIWindow?
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
// Override point for customization after application launch.
self.window = UIWindow(frame: UIScreen.main.bounds)
IQKeyboardManager.shared.enable = true
IQKeyboardManager.shared.shouldResignOnTouchOutside = true
IQKeyboardManager.shared.enableAutoToolbar = false
//IQKeyboardManager.shared.toolbarTintColor = .white
//IQKeyboardManager.shared.toolbarBarTintColor = ColorSet.appTheamColor
kSharedAppDelegate?.moveToSplashVC()
return true
}
func applicationDidBecomeActive(_ application: UIApplication) {
// Check we can access the application window
guard let window = UIApplication.shared.windows.first else {
return
}
// Check we can access the root viewController
guard let vc = window.rootViewController else {
return
}
// Check the root vc is the type that we want to dismiss
if vc is NoInternetPopUpViewController {
vc.dismiss(animated: true, completion: nil)
}
}
//MARK:- Show No Internet connection VC
func showNoInterNetVC() {
guard let controller = UIStoryboard(name: Storyboards.kNoInternet, bundle: nil).instantiateViewController(withIdentifier: Identifiers.kNoInternetPopUpViewController) as? NoInternetPopUpViewController else {return}
controller.modalPresentationStyle = .overFullScreen
controller.modalTransitionStyle = .crossDissolve
kSharedAppDelegate?.window?.rootViewController?.present(controller, animated: true, completion: nil)
//window.present(controller , animated: true)
}
}

Answer 1

I think pop is the wrong terminology here unless you are using a navigation controller.
If you want to dismiss the currently presented viewController you could check the rootViewController of the applications Window like this.
// Check we can access the application window
guard let window = UIApplication.shared.windows.first else {
return
}
// Check we can access the root viewController
guard let vc = window.rootViewController else {
return
}
// Check the root vc is the type that we want to dismiss
if vc is NoInternetPopUpViewController {
vc.dismiss(animated: true, completion: nil)
}
I also just noticed that you may not need to access the application singleton via the shared property, as applicationDidBecomeActive(_ application: UIApplication) is passing you the Application already - that line would become:
guard let window = application.windows.first else {

Answer 2

There is another way to do this, in newer iOS versions you directly have access to topViewController() so you access it like UIApplication.topViewController() the only downside of it is that you need yo wrap it into an if let statement to check if it is not null. FYI, It won’t be null in most cases if you have let your didFinishLaunching() method run at least once in your app delegate. So that it can stack a view controller to be a top view controller. This won’t be a problem for you since all of the other methods will fail as well if this is the case.
Todo a pop view controller now all you need to do it use top view controller and perform pop on its navigation view controller, or you can dismiss it in case there is no navigation view controller.