Xcode: didTransition to Won't Run in iMessage Extension - swift

Question

I am making an iMessage extension that uses the didTransition(to:). However, the function won't run when I resize the iMessage extension in the simulator. Am I doing something wrong?
This is the code I have:
import UIKit
import Messages
class EditorViewController: MSMessagesAppViewController {
#IBOutlet weak var input: UITextView!
override func viewDidLoad() {
super.viewDidLoad()
input.text = "not changed"
}
// This part isn't working:
override func didTransition(to presentationStyle: MSMessagesAppPresentationStyle) {
input.text = "changed"
}
}
When I resize it in the simulator, nothing happens. The input.text changes the UITextView's text in the viewDidLoad() function, but not in the didTransition(to) function because it never runs.
Am I doing something wrong?
The EditorViewController is a view controller presented by the show (e.g. Push) segue, and has a NavigationController attached to it.
Here is a gif of it not changing:
The input's text never changes
How can I fix this?
EDIT: The willTransition and didTransition functions don't run when the View Controller is embedded in a Navigation Controller. Is there a way to fix this? (It works without the Navigation Controller, but I need the Navigation Controller for this project).

Answer 1

As pointed out in this answer, the entry point of a iMessage App need to be a subclass of MSMessagesAppViewController, so you can not use a NavigationViewController directly as root controller, until Apple adds support for this behavior.
But as suggested, you could solve this with a workaround like this:
import UIKit
import Messages
class MyRootVC: MSMessagesAppViewController {
var navVC: UINavigationViewController!
var editorVC: EditorViewController!
func viewDidLoad() {
super.viewDidLoad()
editorVC = UIStoryboard(name: "Main", bundle: nil).instantiateInitialViewController() as! EditorViewController
navVC = UINavigationController(rootViewController: editorVC)
self.addChild(navVC)
self.view.addSubview(navVC.view)
navVC.didMove(toParent: self)
}
override func didTransition(to presentationStyle: MSMessagesAppPresentationStyle) {
editorVC.input.text = "changed"
}
}
class EditorViewController: UIViewController {
#IBOutlet weak var input: UITextView!
override func viewDidLoad() {
super.viewDidLoad()
input.text = "not changed"
}
}