Coordinator (NavigationCoordinator + TabBarCoordinator)

BaseNavigationCoordinator.swift

import UIKit

// MARK: - Base Coordinator
class NavigationCoordinator: NSObject, Coordinator {

	weak var parentCoordinator: Coordinator?
	var childCoordinators = [Coordinator]()

	var navigationController: BaseNavigationController
	weak var startViewController: UIViewController?

	init(navigationController: BaseNavigationController) {
		self.navigationController = navigationController
		super.init()
		self.navigationController.delegate = self
	}

	func start() {}

}

// MARK: - Handling Coordinator memeory release
extension NavigationCoordinator: UINavigationControllerDelegate {
	func navigationController(_ navigationController: UINavigationController, didShow viewController: UIViewController, animated: Bool) {
		guard let startViewController = startViewController else {
			print("Warning: startViewController is not set. Coordinator \(self.classForCoder) will not be able to deinit.")
			return
		}
		guard
				let fromViewController = navigationController.transitionCoordinator?.viewController(forKey: .from),
				!navigationController.viewControllers.contains(fromViewController)
		else { return }

		// If the popped viewController is the viewController from which this coordinator started then we finish this coordinator to release it.
		if fromViewController == startViewController {
			finish()
		}
	}

	func dismiss(animated: Bool = true) {
		navigationController.dismiss(animated: animated) {
			self.finish()
		}
	}
}

Coordinator+AppDelegate.swift

/// If minimum iOS Target is iOS13, then use SceneDelegete only.
/// Otherwise use both

// MARK: - AppDelegate
class AppDelegate: UIResponder, UIApplicationDelegate {
	var window: UIWindow?
	var appCoordinator: AppCoordinator?

	private func launchAppCoordinator() {
		// If not available iOS 13.0
		if #available(iOS 13.0, *) { } else {
			let window = UIWindow()
			appCoordinator = AppCoordinator(window: window)
			appCoordinator?.start()
			self.window = window
		}
	}
}

// MARK: - SceneDelegate
@available(iOS 13.0, *)
class SceneDelegate: UIResponder, UIWindowSceneDelegate {
	var window: UIWindow?
	var appCoordinator: AppCoordinator?

	func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {
		guard let scene = (scene as? UIWindowScene) else { return }
		launchAppCoordinator(scene)
	}

	private func launchAppCoordinator(_ scence: UIWindowScene) {
		let window = UIWindow(windowScene: scene)
		appCoordinator = AppCoordinator(window: window)
		appCoordinator?.start()
		self.window = window
	}
}

Coordinator.swift

protocol Coordinator: AnyObject {
	var parentCoordinator: Coordinator? { get set }
	var childCoordinators: [Coordinator] { get set }
	func start()
	func finish()
}

extension Coordinator {
	// Default implementation is that the coordinator removes itself from its parent's childCoordinators.
	func finish() {
		parentCoordinator?.childCoordinators.removeAll { $0 === self }
	}
}

SampleAppCoordinator.swift

import UIKit

class AppCoordinator: Coordinator {

	var parentCoordinator: Coordinator?
	var childCoordinators = [Coordinator]()
	var navigationController: BaseNavigationController?

	private let window: UIWindow
	init(window: UIWindow) {
		self.window = window
	}

	func start() {
		navigationController = BaseNavigationController()
		window.rootViewController = navigationController
		window.makeKeyAndVisible()

		let viewModel = SplashViewModel(coordinator: self)
		let viewController = SplashViewController(viewModel: viewModel)
		navigationController?.viewControllers = [viewController]
		navigationController?.modalPresentationStyle = .fullScreen
	}

	func startLoginCoordinator() {
		guard let navigationController = navigationController else { return }
		let coordinator = LoginCoordinator(navigationController: navigationController)
		coordinator.parentCoordinator = self
		coordinator.start()
		childCoordinators = [coordinator]
	}

	func startTabBarCoordinator() {
		navigationController?.viewControllers = []
		navigationController = nil
		let coordinator = TabBarCoordinator(window: window)
		coordinator.parentCoordinator = self
		coordinator.start()
		childCoordinators = [coordinator]
	}

	func logout() {
		childCoordinators = []
		start()
	}

	func finish() {}

}

SampleNavigationCoordinator.swift

import UIKit

class LoginCoordinator: NavigationCoordinator {

	// MARK: - Start
	override func start() {
		let viewModel = LoginViewModel(coordinator: self)
		let viewController = LoginViewController(viewModel: viewModel)
		navigationController.pushViewController(viewController, animated: true)
		navigationController.viewControllers = [viewController]
		startViewController = viewController
	}

	// MARK: - Child coordinators
	func startForgotPasswordCoordinator() {
		let coordinator = ForgotPasswordCoordinator(navigationController: navigationController)
		coordinator.parentCoordinator = self
		coordinator.start()
		childCoordinators.append(coordinator)
	}

	func startRegistrationCoordinator() {
		let coordinator = RegistrationCoordinator(navigationController: navigationController)
		coordinator.parentCoordinator = self
		coordinator.start()
		childCoordinators.append(coordinator)
	}

	func login() {
		childCoordinators = []
		let appCoordinator = UIApplication.shared.appCoordinator
		appCoordinator?.startTabBarCoordinator()
		finish()
	}

}

SampleTabBarController.swift

import UIKit

// MARK: - BaseTabBar
class BaseTabBarController: UITabBarController {
	private(set) var coordinators = [NavigationCoordinator]()

	override func viewDidLoad() {
		super.viewDidLoad()

		setupCustomization()
		setupViewControllers()
	}

	func setupCustomization() {}
	func setupViewControllers() {}
}

// MARK: - SampleTabBar
class SampleTabBarController: BaseTabBarController {

	override func setupCustomization() {
		tabBar.tintColor = .mainAccent
	}

	override func setupViewControllers() {

		let apartmentCoordinator = ApartmentsCoordinator(navigationController: BaseNavigationController())
		apartmentCoordinator.navigationController.tabBarItem = UITabBarItem(title: "Apartments", image: UIImage(named: "tabbar-apartments"), selectedImage: nil)
		coordinators.append(apartmentCoordinator)

		if User.current.isType(.admin) {
			let usersCoordinator = UsersCoordinator(navigationController: BaseNavigationController())
			usersCoordinator.navigationController.tabBarItem = UITabBarItem(title: "Users", image: UIImage(named: "tabbar-users"), selectedImage: nil)
			coordinators.append(usersCoordinator)
		}

		let profileCoordinator = ProfileCoordinator(navigationController: BaseNavigationController())
		profileCoordinator.navigationController.tabBarItem = UITabBarItem(title: "Profile", image: UIImage(named: "tabbar-profile"), selectedImage: nil)
		coordinators.append(profileCoordinator)

		let settingsCoordinator = SettingsCoordinator(navigationController: BaseNavigationController())
		settingsCoordinator.navigationController.tabBarItem = UITabBarItem(title: "Settings", image: UIImage(named: "tabbar-settings"), selectedImage: nil)
		coordinators.append(settingsCoordinator)

		viewControllers = coordinators.map { $0.navigationController }
		coordinators.forEach { $0.start() }
	}
}

SampleTabBarCoordinator.swift

import UIKit

class TabBarCoordinator: NSObject, Coordinator {
	
	weak var parentCoordinator: Coordinator?
	var childCoordinators = [Coordinator]()
	let tabBarController = SampleTabBarController()
	
	let window: UIWindow
	init(window: UIWindow) {
		self.window = window
	}

	func start() {
		window.rootViewController = tabBarController
		UIView.transition(
			with: window,
			duration: 0.4,
			options: .transitionCrossDissolve,
			animations: {},
			completion: nil
		)
		childCoordinators = tabBarController.coordinators
		childCoordinators.forEach { $0.parentCoordinator = self }
	}
}