How to fix problem with opening ViewController by action from Coordinator in Swift? - ios

Question

I'm trying to open another controller by tapping on the cell of my tableView. I'm coding with MVVM and Coordinator pattern.
In the beginning we see this screen - it is declarated in the method start()
let service = Service()
private(set) weak var navigationController: UINavigationController?
func start() -> UINavigationController {
let vm = ContinentsViewModel(service: service)
let vc = ContinentsViewController(viewModel: vm)
let navigationController = UINavigationController()
self.navigationController = navigationController
navigationController.setViewControllers([vc], animated: false)
bindContinentsViewModel(viewModel: vm)
return navigationController
}
Later, my goal is to open all list of countries of the continent, but now l just need to open empty ViewController by tap on the cell (ex. Africa or Antarctica). Here is my methods for it, but they don't work.
private func showCountries() {
let vc = ViewController()
navigationController?.pushViewController(vc, animated: true)
}
private func bindContinentsViewModel(viewModel: ContinentsViewModel) {
viewModel
.flow
.bind { [weak self] flow in
switch flow {
case .onContinentTap:
self?.showCountries() // don't work
// print("show \(continent)") // work - continent is a param of .onContinentTap, which prints an geo-id of the continent, just if you need to know.
}
}
.disposed(by: viewModel.bag)
}
Thank you so much!

Answer 1

The following works as expected. What are you doing differently?
#main
final class AppDelegate: UIResponder, UIApplicationDelegate {
var window: UIWindow?
var viewModel: ViewModel?
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
viewModel = ViewModel()
let controller = viewModel?.start()
window = UIWindow(frame: UIScreen.main.bounds)
window?.rootViewController = controller
window?.makeKeyAndVisible()
return true
}
}
final class ViewModel {
private(set) weak var navigationController: UINavigationController?
func start() -> UINavigationController {
let vm = ContinentsViewModel()
let vc = ContinentsViewController(viewModel: vm)
let navigationController = UINavigationController()
self.navigationController = navigationController
navigationController.setViewControllers([vc], animated: false)
bindContinentsViewModel(viewModel: vm)
return navigationController
}
private func showCountries() {
let vc = UIViewController()
vc.view.backgroundColor = .blue
navigationController?.pushViewController(vc, animated: true)
}
private func bindContinentsViewModel(viewModel: ContinentsViewModel) {
viewModel.flow
.bind { [weak self] flow in
switch flow {
case .onContinentTap:
self?.showCountries()
}
}
.disposed(by: viewModel.bag)
}
}
final class ContinentsViewModel {
enum Flow {
case onContinentTap
}
let flow: Observable<Flow>
let bag = DisposeBag()
init() {
flow = .just(.onContinentTap)
.delay(.seconds(3), scheduler: MainScheduler.instance)
}
}
final class ContinentsViewController: UIViewController {
var viewModel: ContinentsViewModel
init(viewModel: ContinentsViewModel) {
self.viewModel = viewModel
super.init(nibName: nil, bundle: nil)
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = .red
}
}