Allow registration on matrix.org using a custom helper URL. (#3282)

ElementX/Sources/Screens/Authentication/ServerConfirmationScreen/ServerConfirmationScreenModels.swift

@@ -19,6 +19,8 @@ struct ServerConfirmationScreenViewState: BindableState {
     var homeserverAddress: String
     /// The flow being attempted on the selected homeserver.
     let authenticationFlow: AuthenticationFlow
+    /// Whether or not the homeserver supports registration.
+    var homeserverSupportsRegistration = false
     /// The presentation anchor used for OIDC authentication.
     var window: UIWindow?
     
@@ -37,14 +39,26 @@ struct ServerConfirmationScreenViewState: BindableState {
         switch authenticationFlow {
         case .login:
             if homeserverAddress == "matrix.org" {
-                return L10n.screenServerConfirmationMessageLoginMatrixDotOrg
+                L10n.screenServerConfirmationMessageLoginMatrixDotOrg
             } else if homeserverAddress == "element.io" {
-                return L10n.screenServerConfirmationMessageLoginElementDotIo
+                L10n.screenServerConfirmationMessageLoginElementDotIo
             } else {
-                return ""
+                ""
             }
         case .register:
-            return L10n.screenServerConfirmationMessageRegister
+            if canContinue {
+                L10n.screenServerConfirmationMessageRegister
+            } else {
+                L10n.errorAccountCreationNotPossible
+            }
+        }
+    }
+    
+    /// Whether or not it is valid to continue the flow.
+    var canContinue: Bool {
+        switch authenticationFlow {
+        case .login: true
+        case .register: homeserverSupportsRegistration
         }
     }
 }

ElementX/Sources/Screens/Authentication/ServerConfirmationScreen/ServerConfirmationScreenViewModel.swift

@@ -18,14 +18,18 @@ class ServerConfirmationScreenViewModel: ServerConfirmationScreenViewModelType,
     }
 
     init(authenticationService: AuthenticationServiceProtocol, authenticationFlow: AuthenticationFlow) {
-        super.init(initialViewState: ServerConfirmationScreenViewState(homeserverAddress: authenticationService.homeserver.value.address,
-                                                                       authenticationFlow: authenticationFlow))
+        let homeserver = authenticationService.homeserver.value
+        
+        super.init(initialViewState: ServerConfirmationScreenViewState(homeserverAddress: homeserver.address,
+                                                                       authenticationFlow: authenticationFlow,
+                                                                       homeserverSupportsRegistration: homeserver.supportsRegistration))
         
         authenticationService.homeserver
             .receive(on: DispatchQueue.main)
             .sink { [weak self] homeserver in
                 guard let self else { return }
                 state.homeserverAddress = homeserver.address
+                state.homeserverSupportsRegistration = homeserver.supportsRegistration
             }
             .store(in: &cancellables)
     }
@@ -44,3 +48,9 @@ class ServerConfirmationScreenViewModel: ServerConfirmationScreenViewModelType,
         }
     }
 }
+
+extension LoginHomeserver {
+    var supportsRegistration: Bool {
+        loginMode == .oidc || (address == "matrix.org" && registrationHelperURL != nil)
+    }
+}

ElementX/Sources/Screens/Authentication/ServerConfirmationScreen/View/ServerConfirmationScreen.swift

@@ -5,6 +5,7 @@
 // Please see LICENSE in the repository root for full details.
 //
 
+import Compound
 import SwiftUI
 
 struct ServerConfirmationScreen: View {
@@ -52,6 +53,7 @@ struct ServerConfirmationScreen: View {
             }
             .buttonStyle(.compound(.primary))
             .accessibilityIdentifier(A11yIdentifiers.serverConfirmationScreen.continue)
+            .disabled(!context.viewState.canContinue)
             
             Button { context.send(viewAction: .changeServer) } label: {
                 Text(L10n.screenServerConfirmationChangeServer)