Present a View Controller modally from a tab bar controller - ios

Question

I want to build a view with a camera. Something just like Instagram where there is a button in the middle that the user can click and the camera view shows up.
I implemented a code for the TabViewController in the AppDelegate but nothing happens, no animation or Presentation of the new ViewController.
Here is my AppDelegate:
import UIKit
class AppDelegate: UIResponder, UIApplicationDelegate, UITabBarControllerDelegate {
var window: UIWindow?
func tabBarController(_ tabBarController: UITabBarController, shouldSelect viewController: ViewController) -> Bool {
if viewController is ViewController {
let storyboard = UIStoryboard(name: "Main.storyboard", bundle: nil)
if let controller = storyboard.instantiateViewController(withIdentifier: "cameraVC") as? ViewController {
controller.modalPresentationStyle = .fullScreen
tabBarController.present(controller, animated: true, completion: nil)
}
return false
}
return true
}
Here is my Storyboard:
Any ideas?

Answer 1

I suggest to create a custom class for your TabBarController, then assign the delegate to that.
You can either assign and check the restorationIdentifier of the view controller, or do a type check. I usually use storyboard identifier as the restoration identifier of the view controller(s).
class TabBarController: UITabBarController, UITabBarControllerDelegate {
override func viewDidLoad() {
super.viewDidLoad()
self.delegate = self
}
func tabBarController(_ tabBarController: UITabBarController, shouldSelect viewController: UIViewController) -> Bool {
if let identifier = viewController.restorationIdentifier, identifier == "cameraVC" {
let vc = self.storyboard?.instantiateViewController(withIdentifier: "cameraVC") as! CameraViewController
present(vc, animated: true, completion: nil)
return false
}
return true
}
}
Here's a sample you can play with:
https://gist.github.com/emrekyv/3343aa40c24d7e54244dc09ba0cd95df

Answer 2

I just tried and It worked perfectly for me:
Create a Custom class for your TabBarController and assign it to your Controller in Storyboard.
After that override didSelect of tabBarController and write your presentation code there :
override func tabBar(_ tabBar: UITabBar, didSelect item: UITabBarItem) {
if let controller = self.viewControllers?[self.selectedIndex] as? ViewController {
controller.modalPresentationStyle = .fullScreen
self.present(controller, animated: true, completion: nil
}
}
Hope it helps!!