Opening ViewController In AppDelegate While Keeping Tabbar

Question

In my Xcode project when a user taps on a notification I want to first send them to a certain item in my tabBar then I want to instantiate a view controller and send an obje

Answer 1

In my last live project, I'm using the same approach like yours. So even though I doubt this method is the correct or ideal for handling a push notification from the AppDelegate (I still got a lot of stuff to learn in iOS

Answer 2

I can think of two ways to do that:

1) If that view controller is a UINavigationController you can simply push the profile from wherever you are:

if let tabNavigationController = tabbarController.viewControllers?[3] as? UINavigationController {
    tabbarController.selectedViewController = tabNavigationController
    let profileViewController = ProfileViewController(...)
    // ... set up the profile by setting the user id or whatever you need to do ...
    tabNavigationController.push(profileViewController, animated: true)    // animated or not, your choice ;)
}

---

2) Alternatively, what I like to do is control such things directly from my view controller subclass (in this case, PostListViewController). I have this helper method in a swift file that I include in all of my projects:

extension UIViewController {
    var containedViewController: UIViewController {
        if let navController = self as? UINavigationController, let first = navController.viewControllers.first {
            return first
        }
        return self
    }
}

Then I would do this to push the new view controller:

if let tabViewController = tabbarController.selectedViewController {
    tabbarController.selectedViewController = tabViewController
    if let postListViewController = tabViewController.containedViewController as? PostListViewController {
        postListViewController.goToProfile(for: user)    // you need to get the user reference from somewhere first
    }
}

Answer 3

First of all, you'll to insatiate a TabBarController:

let storyboard = UIStoryboard.init(name: "YourStoryboardName", bundle: nil)
let tabBarController = storyboard.instantiateViewController(withIdentifier: "YourTabBarController") as! UITabBarController

And then insatiate all of the viewControllers of TabBarController. If your viewControllers is embedded in to the UINavigationController? If so, you'll to insatiate a Navigation Controller instead:

let first = storyboard.instantiateViewiController(withIdentifier: "YourFirstNavigationController") as! UINavigationController
let second = storyboard.instantiateViewiController(withIdentifier: "YourSecondNavigationController") as! UINavigationController
let third = storyboard.instantiateViewiController(withIdentifier: "YourThirdNavigationController") as! UINavigationController

Also you should instantiate your desired ViewController too:

let desiredVC = storyboard.instantiateViewController(withIdentifier: "desiredVC") as! ExampleDesiredViewController

Make all of the NavigationControllers as viewControllers of TabBarController:

tabBarController.viewControllers = [first, second, third]

And check: It's about your choice.

if tabBarController.selectedViewController == first {

// Option 1: If you want to present
first.present(desiredVC, animated: true, completion: nil)

// Option 2: If you want to push
first.pushViewController(desiredVC, animated. true)

}

Make tabBarController as a rootViewController:

self.window = UIWindow.init(frame: UIScreen.main.bounds)   
self.window?.rootViewController = tabBarController
self.window?.makeKeyAndVisible()

Finally: It's your completed code:

func openViewController() {

let storyboard = UIStoryboard.init(name: "YourStoryboardName", bundle: nil)
let tabBarController = storyboard.instantiateViewController(withIdentifier: "YourTabBarController") as! UITabBarController

let first = storyboard.instantiateViewiController(withIdentifier: "YourFirstNavigationController") as! UINavigationController
let second = storyboard.instantiateViewiController(withIdentifier: "YourSecondNavigationController") as! UINavigationController
let third = storyboard.instantiateViewiController(withIdentifier: "YourThirdNavigationController") as! UINavigationController

let desiredVC = storyboard.instantiateViewController(withIdentifier: "desiredVC") as! ExampleDesiredViewController

tabBarController.viewControllers = [first, second, third]

if tabBarController.selectedViewController == first {

// Option 1: If you want to present
first.present(desiredVC, animated: true, completion: nil)

// Option 2: If you want to push
first.pushViewController(desiredVC, animated. true)

}

self.window = UIWindow.init(frame: UIScreen.main.bounds)   
self.window?.rootViewController = tabBarController
self.window?.makeKeyAndVisible()

}

If you want to present or push ViewController when the notification is tapped? Try something like that:

extension AppDelegate: UNUserNotificationCenterDelegate {

func userNotificationCenter(_ center: UNUserNotificationCenter, didReceive response: UNNotificationResponse, withCompletionHandler completionHandler: @escaping () -> Void) {

        switch response.actionIdentifier {
        case UNNotificationDefaultActionIdentifier:
            openViewController()
            completionHandler()

        default:
            break;
        }
    }
}