Cached avatar support (from Rust) (#633)

* loading a cached avatar at first, and then actually doing the request so that the avatar can still be displayed without connection

* improved the code

* fix + changelog

* policy on how to fetch the avatar url added

* code improvements

* addressed al PR comments

* improved the error handling

* improved the async task code

* fixed a typo

* fixed another typo

Dangerfile.swift

@@ -49,7 +49,8 @@ let allowList = ["stefanceriu",
                  "manuroe",
                  "gileluard",
                  "phlniji",
-                 "aringenbach"]
+                 "aringenbach",
+                 "Velin92"]
 
 let requiresSignOff = !allowList.contains(where: {
     $0.caseInsensitiveCompare(danger.github.pullRequest.user.login) == .orderedSame

ElementX.xcodeproj/project.xcworkspace/xcshareddata/swiftpm/Package.resolved

@@ -95,8 +95,8 @@
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/matrix-org/matrix-rust-components-swift",
       "state" : {
-        "revision" : "32645162ea39badc586d610d2ada6bbc52f398ba",
+        "revision" : "8d7ace5140d0f024b9a03939cdff29c837dc5645",
-        "version" : "1.0.43-alpha"
+        "version" : "1.0.45-alpha"
       }
     },
     {

ElementX/Sources/Screens/HomeScreen/HomeScreenViewModel.swift

@@ -30,7 +30,7 @@ class HomeScreenViewModel: HomeScreenViewModelType, HomeScreenViewModelProtocol
     
     var callback: ((HomeScreenViewModelAction) -> Void)?
     
-    // swiftlint:disable:next function_body_length cyclomatic_complexity
+    // swiftlint:disable:next function_body_length
     init(userSession: UserSessionProtocol, attributedStringBuilder: AttributedStringBuilderProtocol) {
         self.userSession = userSession
         self.attributedStringBuilder = attributedStringBuilder
@@ -55,6 +55,10 @@ class HomeScreenViewModel: HomeScreenViewModelType, HomeScreenViewModelProtocol
             }
             .store(in: &cancellables)
 
+        userSession.clientProxy.avatarURLPublisher
+            .weakAssign(to: \.state.userAvatarURL, on: self)
+            .store(in: &cancellables)
+        
         guard let visibleRoomsSummaryProvider, let allRoomsSummaryProvider else {
             MXLog.error("Room summary provider unavailable")
             return
@@ -91,9 +95,7 @@ class HomeScreenViewModel: HomeScreenViewModelType, HomeScreenViewModelProtocol
                 // Delay user profile detail loading until after the initial room list loads
                 if roomListMode == .rooms {
                     Task {
-                        if case let .success(url) = await userSession.clientProxy.loadUserAvatarURL() {
+                        await userSession.clientProxy.loadUserAvatarURL()
-                            self.state.userAvatarURL = url
-                        }
                     }
                     
                     Task {

ElementX/Sources/Screens/Settings/SettingsScreenViewModel.swift

@@ -44,10 +44,12 @@ class SettingsScreenViewModel: SettingsScreenViewModelType, SettingsScreenViewMo
             .weakAssign(to: \.state.bindings.timelineStyle, on: self)
             .store(in: &cancellables)
 
+        userSession.clientProxy.avatarURLPublisher
+            .weakAssign(to: \.state.userAvatarURL, on: self)
+            .store(in: &cancellables)
+        
         Task {
-            if case let .success(userAvatarURL) = await userSession.clientProxy.loadUserAvatarURL() {
+            await userSession.clientProxy.loadUserAvatarURL()
-                state.userAvatarURL = userAvatarURL
-            }
         }
         
         Task {

ElementX/Sources/Services/Client/ClientProxy.swift

@@ -59,6 +59,15 @@ class ClientProxy: ClientProxyProtocol {
     var allRoomsSlidingSyncView: SlidingSyncList?
     var allRoomsSummaryProvider: RoomSummaryProviderProtocol?
 
+    private var loadCachedAvatarURLTask: Task<Void, Never>?
+    private let avatarURLSubject = CurrentValueSubject<URL?, Never>(nil)
+    var avatarURLPublisher: AnyPublisher<URL?, Never> {
+        avatarURLSubject
+            .removeDuplicates()
+            .receive(on: DispatchQueue.main)
+            .eraseToAnyPublisher()
+    }
+    
     private var cancellables = Set<AnyCancellable>()
     private var visibleRoomsViewProxyStateObservationToken: AnyCancellable?
     
@@ -82,6 +91,8 @@ class ClientProxy: ClientProxyProtocol {
         client.setDelegate(delegate: WeakClientProxyWrapper(clientProxy: self))
         
         configureSlidingSync()
+
+        loadUserAvatarURLFromCache()
     }
     
     var userID: String {
@@ -147,6 +158,7 @@ class ClientProxy: ClientProxyProtocol {
     func loadUserDisplayName() async -> Result<String, ClientProxyError> {
         await Task.dispatch(on: clientQueue) {
             do {
+                self.loadCachedAvatarURLTask?.cancel()
                 let displayName = try self.client.displayName()
                 return .success(displayName)
             } catch {
@@ -155,19 +167,14 @@ class ClientProxy: ClientProxyProtocol {
         }
     }
 
-    func loadUserAvatarURL() async -> Result<URL, ClientProxyError> {
+    func loadUserAvatarURL() async {
         await Task.dispatch(on: clientQueue) {
             do {
                 let urlString = try self.client.avatarUrl()
-                
+                self.avatarURLSubject.value = urlString.flatMap(URL.init)
-                guard let url = URL(string: urlString) else {
-                    MXLog.error("Invalid avatar URL string: \(String(describing: urlString))")
-                    return .failure(.failedRetrievingAvatarURL)
-                }
-                 
-                return .success(url)
             } catch {
-                return .failure(.failedRetrievingAvatarURL)
+                MXLog.error("Failed fetching the user avatar url: \(error)")
+                return
             }
         }
     }
@@ -233,6 +240,21 @@ class ClientProxy: ClientProxyProtocol {
     
     // MARK: Private
 
+    private func loadUserAvatarURLFromCache() {
+        loadCachedAvatarURLTask = Task {
+            let urlString = await Task.dispatch(on: clientQueue) {
+                do {
+                    return try self.client.cachedAvatarUrl()
+                } catch {
+                    MXLog.error("Failed to look for the avatar url in the cache: \(error)")
+                    return nil
+                }
+            }
+            guard !Task.isCancelled else { return }
+            self.avatarURLSubject.value = urlString.flatMap(URL.init)
+        }
+    }
+    
     private func restartSync() {
         MXLog.info("Restarting sync")
         stopSync()

ElementX/Sources/Services/Client/ClientProxyProtocol.swift

@@ -24,7 +24,6 @@ enum ClientProxyCallback {
 }
 
 enum ClientProxyError: Error {
-    case failedRetrievingAvatarURL
     case failedRetrievingDisplayName
     case failedRetrievingAccountData
     case failedSettingAccountData
@@ -72,6 +71,8 @@ protocol ClientProxyProtocol: AnyObject, MediaLoaderProtocol {
 
     var homeserver: String { get }
 
+    var avatarURLPublisher: AnyPublisher<URL?, Never> { get }
+
     var restorationToken: RestorationToken? { get }
     
     var visibleRoomsSummaryProvider: RoomSummaryProviderProtocol? { get }
@@ -86,7 +87,7 @@ protocol ClientProxyProtocol: AnyObject, MediaLoaderProtocol {
     
     func loadUserDisplayName() async -> Result<String, ClientProxyError>
 
-    func loadUserAvatarURL() async -> Result<URL, ClientProxyError>
+    func loadUserAvatarURL() async
 
     func accountDataEvent<Content: Decodable>(type: String) async -> Result<Content?, ClientProxyError>
     

ElementX/Sources/Services/Client/MockClientProxy.swift

@@ -30,11 +30,15 @@ class MockClientProxy: ClientProxyProtocol {
     
     var allRoomsSummaryProvider: RoomSummaryProviderProtocol? = MockRoomSummaryProvider()
 
+    var avatarURLPublisher: AnyPublisher<URL?, Never> { Empty().eraseToAnyPublisher() }
+    
     internal init(userID: String, roomSummaryProvider: RoomSummaryProviderProtocol? = MockRoomSummaryProvider()) {
         self.userID = userID
         visibleRoomsSummaryProvider = roomSummaryProvider
     }
 
+    func loadUserAvatarURL() async { }
+    
     func startSync() { }
     
     func stopSync() { }
@@ -56,10 +60,6 @@ class MockClientProxy: ClientProxyProtocol {
         .success("User display name")
     }
     
-    func loadUserAvatarURL() async -> Result<URL, ClientProxyError> {
-        .failure(.failedRetrievingAvatarURL)
-    }
-    
     func accountDataEvent<Content>(type: String) async -> Result<Content?, ClientProxyError> where Content: Decodable {
         .failure(.failedRetrievingAccountData)
     }

UnitTests/Sources/MediaProvider/MediaLoaderTests.swift

@@ -83,7 +83,9 @@ private class MockMediaLoadingClient: ClientProtocol {
     
     func setDisplayName(name: String) throws { }
     
-    func avatarUrl() throws -> String { fatalError() }
+    func avatarUrl() throws -> String? { fatalError() }
+
+    func cachedAvatarUrl() throws -> String? { fatalError() }
     
     func deviceId() throws -> String { fatalError() }
     

changelog.d/550.change

@@ -0,0 +1 @@
+Avatar url is now cached on the rust side.

project.yml

@@ -40,7 +40,7 @@ include:
 packages:
   MatrixRustSDK:
     url: https://github.com/matrix-org/matrix-rust-components-swift
-    exactVersion: 1.0.43-alpha
+    exactVersion: 1.0.45-alpha
     # path: ../matrix-rust-sdk
   DesignKit:
     path: DesignKit