Rename completion to callback and simplify actor usage.

Riot/Modules/Onboarding/AuthenticationCoordinator.swift

@@ -133,7 +133,7 @@ final class AuthenticationCoordinator: NSObject, AuthenticationCoordinatorProtoc
         let parameters = AuthenticationServerSelectionCoordinatorParameters(authenticationService: authenticationService,
                                                                             hasModalPresentation: false)
         let coordinator = AuthenticationServerSelectionCoordinator(parameters: parameters)
-        coordinator.completion = { [weak self, weak coordinator] result in
+        coordinator.callback = { [weak self, weak coordinator] result in
             guard let self = self, let coordinator = coordinator else { return }
             self.serverSelectionCoordinator(coordinator, didCompleteWith: result)
         }
@@ -171,7 +171,7 @@ final class AuthenticationCoordinator: NSObject, AuthenticationCoordinatorProtoc
                                                                          registrationFlow: homeserver.registrationFlow,
                                                                          loginMode: homeserver.preferredLoginMode)
         let coordinator = AuthenticationRegistrationCoordinator(parameters: parameters)
-        coordinator.completion = { [weak self, weak coordinator] result in
+        coordinator.callback = { [weak self, weak coordinator] result in
             guard let self = self, let coordinator = coordinator else { return }
             self.registrationCoordinator(coordinator, didCompleteWith: result)
         }
@@ -193,8 +193,6 @@ final class AuthenticationCoordinator: NSObject, AuthenticationCoordinatorProtoc
     @MainActor private func registrationCoordinator(_ coordinator: AuthenticationRegistrationCoordinator,
                                                     didCompleteWith result: AuthenticationRegistrationCoordinatorResult) {
         switch result {
-        case .selectServer:
-            showServerSelectionScreen()
         case .completed(let result):
             handleRegistrationResult(result)
         }

Riot/Modules/Onboarding/OnboardingCoordinator.swift

@@ -451,7 +451,7 @@ final class OnboardingCoordinator: NSObject, OnboardingCoordinatorProtocol {
         let parameters = OnboardingAvatarCoordinatorParameters(userSession: userSession, avatar: selectedAvatar)
         let coordinator = OnboardingAvatarCoordinator(parameters: parameters)
 
-        coordinator.completion = { [weak self, weak coordinator] result in
+        coordinator.callback = { [weak self, weak coordinator] result in
             guard let self = self, let coordinator = coordinator else { return }
 
             switch result {

RiotSwiftUI/Modules/Authentication/Registration/AuthenticationRegistrationViewModel.swift

@@ -30,7 +30,7 @@ class AuthenticationRegistrationViewModel: AuthenticationRegistrationViewModelTy
 
     // MARK: Public
 
-    @MainActor var completion: ((AuthenticationRegistrationViewModelResult) -> Void)?
+    @MainActor var callback: ((AuthenticationRegistrationViewModelResult) -> Void)?
 
     // MARK: - Setup
 
@@ -47,25 +47,19 @@ class AuthenticationRegistrationViewModel: AuthenticationRegistrationViewModelTy
     // MARK: - Public
 
     override func process(viewAction: AuthenticationRegistrationViewAction) {
-        Task {
-            await MainActor.run {
-                switch viewAction {
-                case .selectServer:
-                    completion?(.selectServer)
-                case .validateUsername:
-                    state.hasEditedUsername = true
-                    completion?(.validateUsername(state.bindings.username))
-                case .enablePasswordValidation:
-                    state.hasEditedPassword = true
-                case .clearUsernameError:
-                    guard state.usernameErrorMessage != nil else { return }
-                    state.usernameErrorMessage = nil
-                case .next:
-                    completion?(.createAccount(username: state.bindings.username, password: state.bindings.password))
-                case .continueWithSSO(let id):
-                    break
-                }
-            }
+        switch viewAction {
+        case .selectServer:
+            Task { await callback?(.selectServer) }
+        case .validateUsername:
+            Task { await clearUsernameError() }
+        case .enablePasswordValidation:
+            Task { await enablePasswordValidation() }
+        case .clearUsernameError:
+            Task { await clearUsernameError() }
+        case .next:
+            Task { await callback?(.createAccount(username: state.bindings.username, password: state.bindings.password)) }
+        case .continueWithSSO(let id):
+            break
         }
     }
 
@@ -95,4 +89,27 @@ class AuthenticationRegistrationViewModel: AuthenticationRegistrationViewModelTy
             state.bindings.alertInfo = AlertInfo(id: type)
         }
     }
+
+    // MARK: - Private
+
+    /// Checks the entered username is valid for use on the current homeserver.
+    @MainActor private func validateUsername() {
+        if !state.hasEditedUsername {
+            state.hasEditedUsername = true
+        }
+
+        callback?(.validateUsername(state.bindings.username))
+    }
+
+    /// Allow password validation to begin taking place.
+    @MainActor private func enablePasswordValidation() {
+        guard !state.hasEditedPassword else { return }
+        state.hasEditedPassword = true
+    }
+
+    /// Clear the error message currently shown in the username footer.
+    @MainActor private func clearUsernameError() {
+        guard state.usernameErrorMessage != nil else { return }
+        state.usernameErrorMessage = nil
+    }
 }

RiotSwiftUI/Modules/Authentication/Registration/AuthenticationRegistrationViewModelProtocol.swift

@@ -18,7 +18,7 @@ import Foundation
 
 protocol AuthenticationRegistrationViewModelProtocol {
 
-    @MainActor var completion: ((AuthenticationRegistrationViewModelResult) -> Void)? { get set }
+    @MainActor var callback: ((AuthenticationRegistrationViewModelResult) -> Void)? { get set }
     @available(iOS 14, *)
     var context: AuthenticationRegistrationViewModelType.Context { get }
 

RiotSwiftUI/Modules/Authentication/Registration/Coordinator/AuthenticationRegistrationCoordinator.swift

@@ -29,8 +29,6 @@ struct AuthenticationRegistrationCoordinatorParameters {
 }
 
 enum AuthenticationRegistrationCoordinatorResult {
-    /// The user would like to select another server.
-    case selectServer
     /// The screen completed with the associated registration result.
     case completed(RegistrationResult)
 }
@@ -65,7 +63,7 @@ final class AuthenticationRegistrationCoordinator: Coordinator, Presentable {
 
     // Must be used only internally
     var childCoordinators: [Coordinator] = []
-    @MainActor var completion: ((AuthenticationRegistrationCoordinatorResult) -> Void)?
+    @MainActor var callback: ((AuthenticationRegistrationCoordinatorResult) -> Void)?
 
     // MARK: - Setup
 
@@ -89,23 +87,8 @@ final class AuthenticationRegistrationCoordinator: Coordinator, Presentable {
 
     // MARK: - Public
     func start() {
-        Task {
-            await MainActor.run {
-                MXLog.debug("[AuthenticationRegistrationCoordinator] did start.")
-                authenticationRegistrationViewModel.completion = { [weak self] result in
-                    guard let self = self else { return }
-                    MXLog.debug("[AuthenticationRegistrationCoordinator] AuthenticationRegistrationViewModel did complete with result: \(result).")
-                    switch result {
-                    case .selectServer:
-                        self.presentServerSelectionScreen()
-                    case.validateUsername(let username):
-                        self.validateUsername(username)
-                    case .createAccount(let username, let password):
-                        self.createAccount(username: username, password: password)
-                    }
-                }
-            }
-        }
+        MXLog.debug("[AuthenticationRegistrationCoordinator] did start.")
+        Task { await setupViewModel() }
     }
 
     func toPresentable() -> UIViewController {
@@ -114,6 +97,22 @@ final class AuthenticationRegistrationCoordinator: Coordinator, Presentable {
 
     // MARK: - Private
 
+    /// Set up the view model. This method is extracted from `start()` so it can run on the `MainActor`.
+    @MainActor private func setupViewModel() {
+        authenticationRegistrationViewModel.callback = { [weak self] result in
+            guard let self = self else { return }
+            MXLog.debug("[AuthenticationRegistrationCoordinator] AuthenticationRegistrationViewModel did complete with result: \(result).")
+            switch result {
+            case .selectServer:
+                self.presentServerSelectionScreen()
+            case.validateUsername(let username):
+                self.validateUsername(username)
+            case .createAccount(let username, let password):
+                self.createAccount(username: username, password: password)
+            }
+        }
+    }
+
     /// Show a blocking activity indicator whilst saving.
     @MainActor private func startLoading(label: String? = nil) {
         waitingIndicator = indicatorPresenter.present(.loading(label: label ?? VectorL10n.loading, isInteractionBlocking: true))
@@ -162,7 +161,7 @@ final class AuthenticationRegistrationCoordinator: Coordinator, Presentable {
                 let result = try await registrationWizard.createAccount(username: username, password: password, initialDeviceDisplayName: deviceDisplayName)
 
                 guard !Task.isCancelled else { return }
-                completion?(.completed(result))
+                callback?(.completed(result))
 
                 self?.stopLoading()
             } catch {
@@ -213,7 +212,7 @@ final class AuthenticationRegistrationCoordinator: Coordinator, Presentable {
         let parameters = AuthenticationServerSelectionCoordinatorParameters(authenticationService: authenticationService,
                                                                             hasModalPresentation: true)
         let coordinator = AuthenticationServerSelectionCoordinator(parameters: parameters)
-        coordinator.completion = { [weak self, weak coordinator] result in
+        coordinator.callback = { [weak self, weak coordinator] result in
             guard let self = self, let coordinator = coordinator else { return }
             self.serverSelectionCoordinator(coordinator, didCompleteWith: result)
         }

RiotSwiftUI/Modules/Authentication/ServerSelection/AuthenticationServerSelectionViewModel.swift

@@ -29,7 +29,7 @@ class AuthenticationServerSelectionViewModel: AuthenticationServerSelectionViewM
 
     // MARK: Public
 
-    var completion: ((AuthenticationServerSelectionViewModelResult) -> Void)?
+    @MainActor var callback: ((AuthenticationServerSelectionViewModelResult) -> Void)?
 
     // MARK: - Setup
 
@@ -42,20 +42,15 @@ class AuthenticationServerSelectionViewModel: AuthenticationServerSelectionViewM
     // MARK: - Public
 
     override func process(viewAction: AuthenticationServerSelectionViewAction) {
-        Task {
-            await MainActor.run {
-                switch viewAction {
-                case .confirm:
-                    completion?(.confirm(homeserverAddress: state.bindings.homeserverAddress))
-                case .dismiss:
-                    completion?(.dismiss)
-                case .getInTouch:
-                    getInTouch()
-                case .clearFooterError:
-                    guard state.footerErrorMessage != nil else { return }
-                    withAnimation { state.footerErrorMessage = nil }
-                }
-            }
+        switch viewAction {
+        case .confirm:
+            Task { await callback?(.confirm(homeserverAddress: state.bindings.homeserverAddress)) }
+        case .dismiss:
+            Task { await callback?(.dismiss) }
+        case .getInTouch:
+            Task { await getInTouch() }
+        case .clearFooterError:
+            Task { await clearFooterError() }
         }
     }
 
@@ -72,6 +67,11 @@ class AuthenticationServerSelectionViewModel: AuthenticationServerSelectionViewM
 
     // MARK: - Private
 
+    @MainActor private func clearFooterError() {
+        guard state.footerErrorMessage != nil else { return }
+        withAnimation { state.footerErrorMessage = nil }
+    }
+
     /// Opens the EMS link in the user's browser.
     @MainActor private func getInTouch() {
         let url = BuildSettings.onboardingHostYourOwnServerLink

RiotSwiftUI/Modules/Authentication/ServerSelection/AuthenticationServerSelectionViewModelProtocol.swift

@@ -18,7 +18,7 @@ import Foundation
 
 protocol AuthenticationServerSelectionViewModelProtocol {
 
-    @MainActor var completion: ((AuthenticationServerSelectionViewModelResult) -> Void)? { get set }
+    @MainActor var callback: ((AuthenticationServerSelectionViewModelResult) -> Void)? { get set }
     @available(iOS 14, *)
     var context: AuthenticationServerSelectionViewModelType.Context { get }
 

RiotSwiftUI/Modules/Authentication/ServerSelection/Coordinator/AuthenticationServerSelectionCoordinator.swift

@@ -50,7 +50,7 @@ final class AuthenticationServerSelectionCoordinator: Coordinator, Presentable {
 
     // Must be used only internally
     var childCoordinators: [Coordinator] = []
-    @MainActor var completion: ((AuthenticationServerSelectionCoordinatorResult) -> Void)?
+    @MainActor var callback: ((AuthenticationServerSelectionCoordinatorResult) -> Void)?
 
     // MARK: - Setup
 
@@ -72,22 +72,8 @@ final class AuthenticationServerSelectionCoordinator: Coordinator, Presentable {
     // MARK: - Public
 
     func start() {
-        Task {
-            await MainActor.run {
-                MXLog.debug("[AuthenticationServerSelectionCoordinator] did start.")
-                authenticationServerSelectionViewModel.completion = { [weak self] result in
-                    guard let self = self else { return }
-                    MXLog.debug("[AuthenticationServerSelectionCoordinator] AuthenticationServerSelectionViewModel did complete with result: \(result).")
-
-                    switch result {
-                    case .confirm(let homeserverAddress):
-                        self.useHomeserver(homeserverAddress)
-                    case .dismiss:
-                        self.completion?(.dismiss)
-                    }
-                }
-            }
-        }
+        MXLog.debug("[AuthenticationServerSelectionCoordinator] did start.")
+        Task { await setupViewModel() }
     }
 
     func toPresentable() -> UIViewController {
@@ -96,6 +82,21 @@ final class AuthenticationServerSelectionCoordinator: Coordinator, Presentable {
 
     // MARK: - Private
 
+    /// Set up the view model. This method is extracted from `start()` so it can run on the `MainActor`.
+    @MainActor private func setupViewModel() {
+        authenticationServerSelectionViewModel.callback = { [weak self] result in
+            guard let self = self else { return }
+            MXLog.debug("[AuthenticationServerSelectionCoordinator] AuthenticationServerSelectionViewModel did complete with result: \(result).")
+
+            switch result {
+            case .confirm(let homeserverAddress):
+                self.useHomeserver(homeserverAddress)
+            case .dismiss:
+                self.callback?(.dismiss)
+            }
+        }
+    }
+
     /// Show an activity indicator whilst loading.
     /// - Parameters:
     ///   - label: The label to show on the indicator.
@@ -122,7 +123,7 @@ final class AuthenticationServerSelectionCoordinator: Coordinator, Presentable {
                 try await authenticationService.startFlow(.register, for: homeserverAddress)
                 stopLoading()
 
-                completion?(.updated)
+                callback?(.updated)
             } catch {
                 stopLoading()
 

RiotSwiftUI/Modules/Onboarding/Avatar/Coordinator/OnboardingAvatarCoordinator.swift

@@ -24,7 +24,7 @@ struct OnboardingAvatarCoordinatorParameters {
 }
 
 enum OnboardingAvatarCoordinatorResult {
-    /// The user has chosen an image (but hasn't yet saved it).
+    /// The user has chosen an image (but it isn't saved until `.complete` is sent).
     case selectedAvatar(UIImage?)
     /// The screen is finished and the next one can be shown.
     case complete(UserSession)
@@ -64,7 +64,7 @@ final class OnboardingAvatarCoordinator: Coordinator, Presentable {
 
     // Must be used only internally
     var childCoordinators: [Coordinator] = []
-    var completion: ((OnboardingAvatarCoordinatorResult) -> Void)?
+    var callback: ((OnboardingAvatarCoordinatorResult) -> Void)?
 
     // MARK: - Setup
 
@@ -89,7 +89,7 @@ final class OnboardingAvatarCoordinator: Coordinator, Presentable {
 
     func start() {
         MXLog.debug("[OnboardingAvatarCoordinator] did start.")
-        onboardingAvatarViewModel.completion = { [weak self] result in
+        onboardingAvatarViewModel.callback = { [weak self] result in
             guard let self = self else { return }
             MXLog.debug("[OnboardingAvatarCoordinator] OnboardingAvatarViewModel did complete with result: \(result).")
             switch result {
@@ -100,7 +100,7 @@ final class OnboardingAvatarCoordinator: Coordinator, Presentable {
             case .save(let avatar):
                 self.setAvatar(avatar)
             case .skip:
-                self.completion?(.complete(self.parameters.userSession))
+                self.callback?(.complete(self.parameters.userSession))
             }
         }
     }
@@ -162,7 +162,7 @@ final class OnboardingAvatarCoordinator: Coordinator, Presentable {
             self.parameters.userSession.account.setUserAvatarUrl(urlString) { [weak self] in
                 guard let self = self else { return }
                 self.stopWaiting()
-                self.completion?(.complete(self.parameters.userSession))
+                self.callback?(.complete(self.parameters.userSession))
             } failure: { [weak self] error in
                 guard let self = self else { return }
                 self.stopWaiting()
@@ -184,7 +184,7 @@ extension OnboardingAvatarCoordinator: MediaPickerPresenterDelegate {
     /// so whilst this method may not appear to be called, everything works fine when run on a device.
     func mediaPickerPresenter(_ presenter: MediaPickerPresenter, didPickImage image: UIImage) {
         onboardingAvatarViewModel.updateAvatarImage(with: image)
-        completion?(.selectedAvatar(image))
+        callback?(.selectedAvatar(image))
         presenter.dismiss(animated: true, completion: nil)
     }
 
@@ -199,7 +199,7 @@ extension OnboardingAvatarCoordinator: MediaPickerPresenterDelegate {
 extension OnboardingAvatarCoordinator: CameraPresenterDelegate {
     func cameraPresenter(_ presenter: CameraPresenter, didSelectImage image: UIImage) {
         onboardingAvatarViewModel.updateAvatarImage(with: image)
-        completion?(.selectedAvatar(image))
+        callback?(.selectedAvatar(image))
         presenter.dismiss(animated: true, completion: nil)
     }