UIAlertController present state management

[Jinya]

Hi, I'm trying to rewrite an app with TCA based on UIKit, but confused about how to properly manage UIAlertController present state within Reducer right now.

Here is a minimum feature module codes for my case. confirmationDialog of FeatureState is key to notify presenting or dismissing the UIAlertController. However, UIAlertController will automatically dismiss when an alert button tapped to send an specific action to reducer and confirmationDialog still stay non-nil. Should I change the confirmationDialog status in the specific action at the same time? Hope some advices from you.

import UIKit
import Combine
import ComposableArchitecture

struct FeatureState: Equatable {
    var confirmationDialog: ConfirmationDialogState<FeatureAction>? = nil
}

enum FeatureAction: Equatable {
    case setConfirmationDialog(title: String, url: URL)
    case confirmationDialogDismissed
    case open(URL)
    case copy(URL)
}

struct FeatureEnvironment {}

let featureReducer = Reducer<FeatureState, FeatureAction, FeatureEnvironment>.init { state, action, environment in
    switch action {
    case .setConfirmationDialog(let title, let url):
        state.confirmationDialog = .init(
            title: .init(title),
            message: .init(url.absoluteString),
            buttons: [
                .default(.init("Open Link in Safari"), action: .send(.open(url))),
                .default(.init("Copy Link"), action: .send(.copy(url))),
                .cancel(.init("Cancel"), action: .send(.confirmationDialogDismissed))
            ]
        )
        return .none
    case .confirmationDialogDismissed:
        state.confirmationDialog = nil
        return .none
    case .open(let url):
        UIApplication.shared.open(url)
        // Should add `return Effect(value: .confirmationDialogDismissed)` or `state.confirmationDialog = nil` ?
        return .none
    case .copy(let url):
        UIPasteboard.general.string = url.absoluteString
        // Should add `return Effect(value: .confirmationDialogDismissed)` or `state.confirmationDialog = nil` ?
        return .none
    }
}

class FeatureViewController: UIViewController {
    private let viewStore: ViewStore<FeatureState, FeatureAction>

    private weak var alertController: UIAlertController?
    private var cancellables: Set<AnyCancellable> = []

    init(store: Store<FeatureState, FeatureAction>) {
        self.viewStore = ViewStore(store)
        super.init(nibName: nil, bundle: nil)
    }

    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    override func viewDidLoad() {
        super.viewDidLoad()

        let showAlertButton = UIButton(type: .infoLight)
        showAlertButton.addTarget(self, action: #selector(showAlertButtonTapped), for: .touchUpInside)
        view.addSubview(showAlertButton)
        showAlertButton.frame = .init(x: 100, y: 100, width: 200, height: 50)

        viewStore.publisher.confirmationDialog
            .sink { [weak self] confirmationDialog in
                guard let self = self else { return }
                if let confirmationDialog = confirmationDialog {
                    let confirmationDialog = UIAlertController(
                        state: confirmationDialog,
                        send: self.viewStore.send(_:)
                    )
                    self.present(confirmationDialog, animated: true)
                    self.alertController = confirmationDialog
                } else {
                    self.alertController?.dismiss(animated: true)
                    self.alertController = nil
                }
            }
            .store(in: &cancellables)
    }

    @objc func showAlertButtonTapped() {
        let url = URL(string: "https://github.com")!
        viewStore.send(.setConfirmationDialog(title: "Title", url: url))
    }
}