Stop blocking on loading the current user display name and avatar. Improve perceived app startup times.

ElementX/Sources/Screens/HomeScreen/HomeScreenCoordinator.swift

@@ -54,11 +54,7 @@ final class HomeScreenCoordinator: Coordinator, Presentable {
     init(parameters: HomeScreenCoordinatorParameters) {
         self.parameters = parameters
         
-        let userDisplayName = parameters.userSession.userDisplayName ?? parameters.userSession.userIdentifier
+        viewModel = HomeScreenViewModel(attributedStringBuilder: parameters.attributedStringBuilder)
-        viewModel = HomeScreenViewModel(userDisplayName: userDisplayName,
-                                        userAvatarURL: parameters.userSession.userAvatarURL,
-                                        mediaProvider: parameters.mediaProvider,
-                                        attributedStringBuilder: parameters.attributedStringBuilder)
         
         let view = HomeScreen(context: viewModel.context)
         hostingController = UIHostingController(rootView: view)
@@ -82,6 +78,22 @@ final class HomeScreenCoordinator: Coordinator, Presentable {
         }.store(in: &cancellables)
         
         updateRoomsList()
+        
+        parameters.userSession.userAvatarURL { [weak self] result in
+            if case let .success(avatarURL) = result {
+                self?.parameters.mediaProvider.loadImageFromURL(avatarURL) { result in
+                    if case let .success(avatar) = result {
+                        self?.viewModel.updateWithUserAvatar(avatar)
+                    }
+                }
+            }
+        }
+        
+        parameters.userSession.userDisplayName { [weak self] result in
+            if case let .success(displayName) = result {
+                self?.viewModel.updateWithUserDisplayName(displayName)
+            }
+        }
     }
     
     // MARK: - Public

ElementX/Sources/Screens/HomeScreen/HomeScreenModels.swift

@@ -29,7 +29,7 @@ enum HomeScreenViewAction {
 }
 
 struct HomeScreenViewState: BindableState {
-    let userDisplayName: String
+    var userDisplayName: String?
     var userAvatar: UIImage?
     
     var rooms: [HomeScreenRoom] = []

ElementX/Sources/Screens/HomeScreen/HomeScreenViewModel.swift

@@ -24,7 +24,6 @@ typealias HomeScreenViewModelType = StateStoreViewModel<HomeScreenViewState,
 @available(iOS 14, *)
 class HomeScreenViewModel: HomeScreenViewModelType, HomeScreenViewModelProtocol {
     
-    private let mediaProvider: MediaProviderProtocol
     private let attributedStringBuilder: AttributedStringBuilderProtocol
     
     private var roomUpdateListeners = Set<AnyCancellable>()
@@ -34,27 +33,15 @@ class HomeScreenViewModel: HomeScreenViewModelType, HomeScreenViewModelProtocol
             self.state.isLoadingRooms = (roomList?.count ?? 0 == 0)
         }
     }
-
+    
     var completion: ((HomeScreenViewModelResult) -> Void)?
     
     // MARK: - Setup
     
-    init(userDisplayName: String,
+    init(attributedStringBuilder: AttributedStringBuilderProtocol) {
-         userAvatarURL: String?,
-         mediaProvider: MediaProviderProtocol,
-         attributedStringBuilder: AttributedStringBuilderProtocol) {
-        self.mediaProvider = mediaProvider
         self.attributedStringBuilder = attributedStringBuilder
         
-        super.init(initialViewState: HomeScreenViewState(userDisplayName: userDisplayName, isLoadingRooms: true))
+        super.init(initialViewState: HomeScreenViewState(isLoadingRooms: true))
-        
-        if let userAvatarURL = userAvatarURL {
-            mediaProvider.loadImageFromURL(userAvatarURL) { [weak self] result in
-                if case let .success(avatar) =  result {
-                    self?.state.userAvatar = avatar
-                }
-            }
-        }
     }
     
     // MARK: - Public
@@ -97,10 +84,14 @@ class HomeScreenViewModel: HomeScreenViewModelType, HomeScreenViewModelProtocol
         
     }
     
-    func updateWithUserAvatar(_ avatar: UIImage?) {
+    func updateWithUserAvatar(_ avatar: UIImage) {
         self.state.userAvatar = avatar
     }
     
+    func updateWithUserDisplayName(_ displayName: String) {
+        self.state.userDisplayName = displayName
+    }
+    
     // MARK: - Private
     
     private func loadRoomDataForIdentifier(_ roomIdentifier: String) {

ElementX/Sources/Screens/HomeScreen/HomeScreenViewModelProtocol.swift

@@ -22,5 +22,7 @@ protocol HomeScreenViewModelProtocol {
     
     var context: HomeScreenViewModelType.Context { get }
     
+    func updateWithUserAvatar(_ avatar: UIImage)
+    func updateWithUserDisplayName(_ displayName: String)
     func updateWithRoomList(_ roomList: [RoomSummaryProtocol])
 }

ElementX/Sources/Screens/HomeScreen/View/HomeScreen.swift

@@ -73,18 +73,32 @@ struct HomeScreen: View {
         .toolbar {
             ToolbarItem(placement: .navigationBarLeading) {
                 HStack {
-                    if let avatar = context.viewState.userAvatar {
+                    ZStack {
-                        Image(uiImage: avatar)
+                        if let avatar = context.viewState.userAvatar {
-                            .resizable()
+                            Image(uiImage: avatar)
-                            .scaledToFill()
+                                .resizable()
-                            .frame(width: 40, height: 40, alignment: .center)
+                                .scaledToFill()
-                            .mask(Circle())
+                                .frame(width: 40, height: 40, alignment: .center)
+                                .mask(Circle())
+                        } else {
+                            EmptyView()
+                        }
                     }
-                    Text("Hello, \(context.viewState.userDisplayName)!")
+                    .animation(.easeInOut, value: context.viewState.userAvatar)
-                        .font(.subheadline)
+                    .transition(.opacity)
-                        .fontWeight(.bold)
+                    
+                    ZStack {
+                        if let displayName = context.viewState.userDisplayName {
+                            Text("Hello, \(displayName)!")
+                                .font(.subheadline)
+                                .fontWeight(.bold)
+                        } else {
+                            EmptyView()
+                        }
+                    }
+                    .animation(.easeInOut, value: context.viewState.userDisplayName)
+                    .transition(.opacity)
                 }
-                .animation(.easeInOut, value: context.viewState.userAvatar)
             }
             ToolbarItem(placement: .navigationBarTrailing) {
                 Button("Logout") {
@@ -153,10 +167,7 @@ struct RoomCell: View {
 
 struct HomeScreen_Previews: PreviewProvider {
     static var previews: some View {
-        let viewModel = HomeScreenViewModel(userDisplayName: "Johnny Appleseed",
+        let viewModel = HomeScreenViewModel(attributedStringBuilder: AttributedStringBuilder())
-                                            userAvatarURL: nil,
-                                            mediaProvider: MockMediaProvider(),
-                                            attributedStringBuilder: AttributedStringBuilder())
         
         let eventBrief = EventBrief(eventId: "id",
                                     senderId: "senderId",
@@ -171,7 +182,9 @@ struct HomeScreen_Previews: PreviewProvider {
         
         viewModel.updateWithRoomList(rooms)
         
-        viewModel.updateWithUserAvatar(UIImage(systemName: "person.fill.questionmark"))
+        if let avatarImage = UIImage(systemName: "person.fill.questionmark") {
+            viewModel.updateWithUserAvatar(avatarImage)
+        }
         
         return HomeScreen(context: viewModel.context)
     }

ElementX/Sources/Services/Authentication/UserSession.swift

@@ -15,6 +15,11 @@ enum UserSessionCallback {
     case updatedRoomsList
 }
 
+enum UserSessionError: Error {
+    case failedRetrievingAvatarURL
+    case failedRetrievingDisplayName
+}
+
 private class WeakUserSessionWrapper: ClientDelegate {
     private weak var userSession: UserSession?
     
@@ -70,21 +75,35 @@ class UserSession: ClientDelegate {
         }
     }
     
-    var userDisplayName: String? {
+    func userDisplayName(_ completion: @escaping (Result<String, UserSessionError>) -> Void) {
-        do {
+        processingQueue.async {
-            return try client.displayName()
+            do {
-        } catch {
+                let displayName = try self.client.displayName()
-            MXLog.error("Failed retrieving the user's display name with error: \(error)")
+                
-            return nil
+                DispatchQueue.main.async {
+                    completion(.success(displayName))
+                }
+            } catch {
+                DispatchQueue.main.async {
+                    completion(.failure(UserSessionError.failedRetrievingDisplayName))
+                }
+            }
         }
     }
     
-    var userAvatarURL: String? {
+    func userAvatarURL(_ completion: @escaping (Result<String, UserSessionError>) -> Void) {
-        do {
+        processingQueue.async {
-            return try client.avatarUrl()
+            do {
-        } catch {
+                let displayName = try self.client.avatarUrl()
-            MXLog.error("Failed retrieving the user's avatar URL with error: \(error)")
+                
-            return nil
+                DispatchQueue.main.async {
+                    completion(.success(displayName))
+                }
+            } catch {
+                DispatchQueue.main.async {
+                    completion(.failure(UserSessionError.failedRetrievingDisplayName))
+                }
+            }
         }
     }