I would like to understand what would be the best way to implement a delegate out UIViewController class
How can I manage the delegate using controller: UIViewController parameter of my function in AuthManager?
These are the two classes I'm working with .. I show you small examples to make you understand
class StartController: UIViewController {
#objc private func presentAuthFacebookController() {
AuthManager.signInWithFacebook(controller: self)
}
}
class AuthManager {
static func signInWithFacebook(controller: UIViewController) {
let loginManager = LoginManager()
loginManager.logIn(permissions: [.publicProfile, .email], viewController: controller) { (result) in
switch result {
case .cancelled : print("\n AuthFacebook: operazione annullata dall'utente \n")
case .failed(let error) : print("\n AuthFacebook: \(error) \n")
case .success(granted: _, declined: let declinedPermission, token: _):
let authVC = ExistingEmailController()
authVC.delegate = // ?????? (controller)
UIApplication.shared.windows.first?.rootViewController?.present(authVC, animated: true, completion: nil)
}
}
}
}
I personally don't think StartController should know about/conform to ExistingEmailControllerDelegate. But if you really want, you can declare controller as a composition type:
static func signInWithFacebook(controller: UIViewController & ExistingEmailControllerDelegate) {
...
authVC.delegate = controller
In my opinion, the whole point of having a AuthManager is to create a layer of abstraction on top of ExistingEmailController, and to encapsulate the logic of authentication. Therefore, StartController shouldn't know, or care, about ExistingEmailControllerDelegate. It only knows about AuthManager.
AuthManager should be the delegate of ExistingEmailController, which implies that signInWithFacebook should not be static, and AuthManager can have an AuthManagerDelegate that StartController conforms to:
class AuthManager : ExistingEmailControllerDelegate {
weak var delegate: AuthManagerDelegate?
func signInWithFacebook(controller: UIViewController) {
...
let authVC = ExistingEmailController()
authVC.delegate = self
UIApplication.shared.windows.first?.rootViewController?.present(authVC, animated: true, completion: nil)
}
func someMethodFromExistingEmailControllerDelegate() {
delegate?.someMethod() // delegating it self.delegate, which StartController conforms to
}
}
protocol AuthManagerDelegate : class {
func someMethod()
}
class StartController: UIViewController, AuthManagerDelegate {
var authManager: AuthManager!
override func viewDidLoad() {
authManager = AuthManager()
authManager.delegate = self
}
#objc private func presentAuthFacebookController() {
authManager.signInWithFacebook(controller: self)
}
func someMethod() {
// write here the code that you would have written in someMethodFromExistingEmailControllerDelegate
}
}
Related
I want to trigger an action on button tap with my callback. Also I have presenter and coordinator. But nothing happenes. My code is not working in this closure:
startViewController.output = { [weak self] action in
switch action {
case .registrationButtonTapped:
self?.showRegistrationViewController()
case .loginButtonTapped:
self?.showLoginViewController()
}
}
In my ViewController I have enum:
enum StartViewControllerButton {
case registrationButtonTapped
case loginButtonTapped
}
callback:
var output: ((StartViewControllerButton) -> Void)?
and selectors:
#objc func registrationButtonPressed() {
startModulPresenter.openNextScreen()
self.output?(.registrationButtonTapped)
}
#objc func loginButtonPressed() {
startModulPresenter.openNextScreen()
self.output?(.loginButtonTapped)
}
My Presenter
class StartModulPresenter: StartModulPresenterProtocol {
var navigationController: UINavigationController
var coordinator: CoordinatorProtocol?
//Init
init(navigationController: UINavigationController) {
self.navigationController = navigationController
coordinator = AuthorizationCoordinator(navigationController: navigationController)
}
//Functions
func openNextScreen() {
coordinator?.start()
}
}
My Coordinator:
class AuthorizationCoordinator: RegistrationCoordinatorProtocol {
var presenter: PresenterProtocol?
var navigationController: UINavigationController
var childCoordinators: [CoordinatorProtocol] = []
//Init
init(navigationController: UINavigationController) {
self.navigationController = navigationController
}
func start() {
presenter = StartModulPresenter(navigationController: navigationController)
let startViewController = StartViewController(startModulPresenter: presenter as! StartModulPresenter)
startViewController.output = { [weak self] action in
switch action {
case .registrationButtonTapped:
self?.showRegistrationViewController()
case .loginButtonTapped:
self?.showLoginViewController()
}
}
}
private func showRegistrationViewController() {
let registrationViewController = RegistrationViewController()
registrationViewController.view.backgroundColor = .orange
self.navigationController.pushViewController(registrationViewController, animated: true)
}
private func showLoginViewController() {
let loginViewController = LoginViewController()
loginViewController.view.backgroundColor = .orange
self.navigationController.pushViewController(loginViewController, animated: true)
}
}
Could you check if startViewController is pushed/presented or not?
func start() {
presenter = StartModulPresenter(navigationController: navigationController)
let startViewController = StartViewController(startModulPresenter: presenter as! StartModulPresenter)
startViewController.output = { [weak self] action in
switch action {
case .registrationButtonTapped:
self?.showRegistrationViewController()
case .loginButtonTapped:
self?.showLoginViewController()
}
}
}
And, is self.output is nil or not? If it is nil please check your assignment call, it needed to be called before you use this variable.
#objc func loginButtonPressed() {
startModulPresenter.openNextScreen()
self.output?(.loginButtonTapped)
}
Honestly, I don't recommend you to use this design pattern, just a simple thing but the real result is too complicated.
Just use protocol-based MVC. View communicate with Controller via protocol/closure or Reactive-based with Combine (PassthroughSubject/CurrentValueSubject)
My Model saves data to Firestore. Once that data is saved, I'd like it to alert my ViewController so that a function can be called. However, nothing is being passed to my ViewController.
This is my Model:
protocol ProtocolModel {
func wasDataSavedSuccessfully(dataSavedSuccessfully:Bool)
}
class Model {
var delegate:ProtocolModel?
func createUserAddedRecipe(
docId:String,
completion: #escaping (Recipe?) -> Void) {
let db = Firestore.firestore()
do {
try db.collection("userFavourites").document(currentUserId).collection("userRecipes").document(docId).setData(from: recipe) { (error) in
print("Data Saved Successfully") // THIS OUTPUTS TO THE CONSOLE
// Notify delegate that data was saved to Firestore
self.delegate?.wasDataSavedSuccessfully(dataSavedSuccessfully: true)
}
}
catch {
print("Error \(error)")
}
}
}
The print("Data Saved Successfully") outputs to the console, but the delegate method right below it doesn't get called.
And this is my ViewController:
class ViewController: UIViewController {
private var model = Model()
override func viewDidLoad() {
super.viewDidLoad()
model.delegate = self
}
}
extension ViewController: ProtocolModel {
func wasDataSavedSuccessfully(dataSavedSuccessfully: Bool) {
if dataSavedSuccessfully == true {
print("Result is true.")
}
else {
print("Result is false.")
}
print("Protocol-Delegate Pattern Works")
}
}
Is there something I'm missing from this pattern? I haven't been able to notice anything different in the articles I've reviewed.
So I test your code and simulate something like that
import UIKit
protocol ProtocolModel {
func wasDataSavedSuccessfully(dataSavedSuccessfully:Bool)
}
class Model {
var delegate:ProtocolModel?
// I use this timer for simulate that firebase store data every 3 seconds for example
var timer: Timer?
func createUserAddedRecipe(
docId:String) {
timer = Timer.scheduledTimer(withTimeInterval: 3, repeats: true, block: { _ in
self.delegate?.wasDataSavedSuccessfully(dataSavedSuccessfully: true)
})
}
}
class NavigationController: UINavigationController {
var model = Model()
override func viewDidLoad() {
super.viewDidLoad()
model.delegate = self
// Call this method to register for network notification
model.createUserAddedRecipe(docId: "exampleId")
}
}
extension NavigationController: ProtocolModel {
func wasDataSavedSuccessfully(dataSavedSuccessfully: Bool) {
print(#function)
}
}
so you can see the result as image below, my delegate update controller that conform to that protocol.
Ideally, I want to create a BaseViewController class that takes in a protocol type (of a delegate) and have a weak variable as the delegate. Something like this:
class BaseViewController<Delegate: AnyObject> {
weak var delegate: Delegate?
init(delegate: Delegate) {
self.delegate = delegate
super.init(...)
}
}
And then inherit from a view controller like so:
protocol MyDelegate: AnyObject {
func funcA()
func funcB()
}
class SomeViewController: BaseViewController<MyDelegate> {
func doSomething() {
delegate?.funcA()
}
}
This doesn't work as the compiler complains:
'BaseViewController' requires that 'MyDelegate' be a class type
How can I work this around to achieve what I need?
Thanks in advance :)
Thats because in swift protocols doesn't confirm to them selves, you can't use "MyProtocol" as concrete type confirming to protocol "MyDelegate"
What you can rather do is
protocol MyDelegate: AnyObject {
func funcA()
func funcB()
}
class BaseViewController<Delegate: MyDelegate> {
weak var delegate: Delegate?
init(delegate: Delegate) {
self.delegate = delegate
super.init(...)
//keeping OPs code as is
}
}
class SomeOtherDelegateClass: MyDelegate {
func funcA() {
//some code here
}
func funcB() {
//some code here
}
}
class SomeViewController: BaseViewController<SomeOtherDelegateClass> {
func doSomething() {
self.delegate?.funcA()
}
}
EDIT 1:
As OP mentioned in comment, he is trying to introduce a generic property in BaseViewController that will simply hold a weak reference to any instance whose class is decided/declared by Child classes of BaseViewController using generics, I am simplifying the above answer a bit
Try this
protocol MyDelegate {
func funcA()
func funcB()
}
class BaseViewController<Delegate> where Delegate: AnyObject {
weak var delegate: Delegate?
init(delegate: Delegate) {
self.delegate = delegate
super.init(...)
//keeping OPs code as is
}
}
class SomeOtherDelegateClass: MyDelegate {
func funcA() {
//some code here
}
func funcB() {
//some code here
}
}
class SomeViewController: BaseViewController<SomeOtherDelegateClass> {
func doSomething() {
self.delegate?.funcA()
}
}
protocol MyDelegate2 {
func funcABCD()
}
class SomeOtherDelegateClass2: MyDelegate2 {
func funcABCD() {
//some code here
}
}
class SomeViewController2: BaseViewController<SomeOtherDelegateClass2> {
func doSomething() {
self.delegate?.funcABCD()
}
}
TBH, I really dont see much of benefit of this design! Probably you need to revisit the code structure and see if you can come up with better code structure :)
You should set your delegate as a constraint for the generic type T in BaseViewController:
protocol MyDelegate: AnyObject {
func funcA()
func funcB()
}
class Delegated1: MyDelegate {
func funcA() { print("A1") }
func funcB() {}
}
class Delegated2: MyDelegate {
func funcA() { print("A2") }
func funcB() {}
}
class BaseViewController<T: MyDelegate>: UIViewController {
var delegate: T?
func doSomething() {
delegate?.funcA()
}
}
class SomeViewController1: BaseViewController<Delegated1> {}
class SomeViewController2: BaseViewController<Delegated2> {}
class TestClass {
let viewController1: SomeViewController1 = {
let viewController = SomeViewController1(nibName: nil, bundle: nil)
viewController.delegate = .init()
return viewController
}()
let viewController2: SomeViewController2 = {
let viewController = SomeViewController2(nibName: nil, bundle: nil)
viewController.delegate = .init()
return viewController
}()
// prints:
// A1
// A2
func myFunc() {
viewController1.doSomething()
viewController2.doSomething()
}
}
I am trying to provide in my app the logout functionality, I would like to know if this way is a good approach to continue.Classes involved are described below:
the first one is the AuthViewCoordinator, which class redirects to the user to auth screens
protocol AuthViewCoordinatorDelegate: class {
func authCompleted(coordinator: AuthViewCoordinator)
}
class AuthViewCoordinator: Coordinator {
weak var fromViewController: UIViewController?
weak var navigationController: UINavigationController?
weak var delegate: AuthViewCoordinatorDelegate?
init(fromViewController: UIViewController, delegate: AuthViewCoordinatorDelegate) {
self.fromViewController = fromViewController
self.delegate = delegate
}
func start() {
let authViewController = UIStoryboard.main.instantiateViewController(withIdentifier: "AuthViewController") as! AuthViewController
authViewController.coordinator = self
let navigationController = NavigationController(rootViewController: authViewController)
navigationController.navigationBar.isHidden = true
fromViewController?.present(navigationController, animated: true, completion: nil)
self.navigationController = navigationController
}
func userDidSelectLogin() {
let loginViewController = UIStoryboard.main.instantiateViewController(withIdentifier: "LoginViewController") as! LoginViewController
loginViewController.viewModel.coordinator = self
self.navigationController?.pushViewController(loginViewController, animated: true)
}
func userDidSelectSignUp() {
let signupViewController = UIStoryboard.main.instantiateViewController(withIdentifier: "SignUpViewController") as! SignUpViewController
signupViewController.viewModel.coordinator = self
self.navigationController?.pushViewController(signupViewController, animated: true)
}
func userDidLogin() {
navigationController?.dismiss(animated: true, completion: nil)
self.delegate?.authCompleted(coordinator: self)
}
func userDidSignUp() {
navigationController?.dismiss(animated: true, completion: nil)
self.delegate?.authCompleted(coordinator: self)
}
}
And the 2nd one is an external class called SessionController. In this class I'm trying to call AuthViewCoordinator().start() inside the function logout immediately after the tokens have been removed to show again the auth screen to the user, but the output is
Use of unresolved identifier 'AuthViewCoordinator'
public class SessionController{
public enum SessionState {
case anonymous
case authenticated
case notAuthenticated
}
let service: Service
let sessionProvider: SessionProvider
convenience public init() {
self.init(service: Service.instance, sessionProvider: SessionProvider.instance)
}
init(service: Service, sessionProvider: SessionProvider) {
self.service = service
self.sessionProvider = sessionProvider
}
public func getMe(completion: #escaping (Error?) -> ()){
service.execute(resource: Login.getMe()) { (result) in
if let error = result.error {
completion(error)
} else if let session = result.value {
print("\n session \(session)\n")
completion(nil)
}
}
}
public func logout() {
self.sessionProvider.removeUserToken()
self.sessionProvider.removeInstanceToken()
self.sessionProvider.removeAnonymousToken()
AuthViewController().start()
}
public func state() -> SessionState {
if let _ = sessionProvider.getUserToken() {
print("###### authenticated #########")
return .authenticated
} else if let _ = sessionProvider.getAnonymousToken() {
print("###### anonymous #########")
return .anonymous
} else {
print("###### notAuthenticated #########")
return .notAuthenticated
}
}
}
I have a "Share on Facebook" button in my app at 3 different view controllers. So I wrote a class which name is "ShareCentral" and i want to do all sharing operations in this class. But for showing share dialog i need to pass uiviewcontroller to my ShareCentral class. I did like that:
class ShareCentral {
var UIVC: UIViewController
init(vc:UIViewController) {
self.UIVC = vc
}
func shareOnFacebook() {
var content = LinkShareContent(url: URL(string:userProfileLink)!)
do {
try ShareDialog.show(from: UIVC, content: content)
}catch (let error) {
print(error)
}
}
}
And this is my view controller:
class SettingsViewController: UIViewController {
let shareCentral = ShareCentral(vc: self)
#IBAction func shareButtonClicked(_ sender: AnyObject) {
self.shareCentral.shareOnFacebook()
}
}
I am getting following compiler error:
SettingsViewController.swift:40:41: Cannot convert value of type '(SettingsViewController) -> () -> (SettingsViewController)' to expected argument type 'UIViewController'
I know if i change the type of UIVC to "SettingsViewController" the problem will disappear. But as i said before i am gonna use this method in three different view controllers.
How can i resolve this problem?
Try this instead :
class ShareCentral {
unowned var UIVC: UIViewController
init(vc:UIViewController) {
self.UIVC = vc
}
func shareOnFacebook() {
var content = LinkShareContent(url: URL(string:userProfileLink)!)
do {
try ShareDialog.show(from: UIVC, content: content)
} catch (let error) {
print(error)
}
}
}
class SettingsViewController: UIViewController {
var shareVC: ShareVC!
override func viewDidLoad() {
super.viewDidLoad()
self.shareVC = ShareVC(vc: self)
}
#IBAction func shareButtonClicked(_ sender: AnyObject) {
self.shareCentral.shareOnFacebook()
}
}