Fetching the room display names in background to avoid blocking the main thread.

Author: stefanceriu

ElementX/Sources/Modules/HomeScreen/HomeScreenModels.swift

@@ -25,7 +25,7 @@ enum HomeScreenViewModelResult {
 enum HomeScreenViewAction {
     case logout
     case loadUserAvatar
-    case loadRoomAvatar(roomId: String)
+    case loadRoomData(roomId: String)
 }
 
 struct HomeScreenViewState: BindableState {
@@ -54,7 +54,8 @@ struct HomeScreenViewState: BindableState {
 
 struct HomeScreenRoom: Identifiable {
     let id: String
-    let displayName: String
+    
+    var displayName: String?
 
     let topic: String?
     let lastMessage: String?

ElementX/Sources/Modules/HomeScreen/HomeScreenViewModel.swift

@@ -52,8 +52,9 @@ class HomeScreenViewModel: HomeScreenViewModelType, HomeScreenViewModelProtocol
         switch viewAction {
         case .logout:
             self.completion?(.logout)
-        case .loadRoomAvatar(let roomId):
+        case .loadRoomData(let roomId):
             self.loadAvatarForRoomWithIdentifier(roomId)
+            self.loadRoomDisplayNameForRoomWithIdentifier(roomId)
         case .loadUserAvatar:
             self.completion?(.loadUserAvatar)
         }
@@ -63,7 +64,7 @@ class HomeScreenViewModel: HomeScreenViewModelType, HomeScreenViewModelProtocol
         self.roomList = roomList
         state.rooms = roomList.map { roomModel in
             HomeScreenRoom(id: roomModel.identifier,
-                           displayName: roomModel.displayName,
+                           displayName: roomModel.name,
                            topic: roomModel.topic,
                            lastMessage: roomModel.lastMessage,
                            isDirect: roomModel.isDirect,
@@ -114,6 +115,31 @@ class HomeScreenViewModel: HomeScreenViewModelType, HomeScreenViewModelProtocol
         }
     }
 
+    private func loadRoomDisplayNameForRoomWithIdentifier(_ roomIdentifier: String) {
+        guard let room = roomList?.filter({ $0.identifier == roomIdentifier }).first else {
+            return
+        }
+        
+        room.loadDisplayName { [weak self] result in
+            guard let self = self else { return }
+            
+            switch result {
+            case .success(let displayName):
+                self.updateDisplayName(displayName, forRoomWithIdentifier: roomIdentifier)
+            default:
+                break
+            }
+        }
+    }
+    
+    private func updateDisplayName(_ displayName: String, forRoomWithIdentifier roomIdentifier: String) {
+        guard let index = self.state.rooms.firstIndex(where: { $0.id == roomIdentifier }) else {
+            return
+        }
+        
+        self.state.rooms[index].displayName = displayName
+    }
+    
     private func updateAvatar(_ avatar: UIImage?, forRoomWithIdentifier roomIdentifier: String) {
         guard let index = self.state.rooms.firstIndex(where: { $0.id == roomIdentifier }) else {
             return

ElementX/Sources/Modules/HomeScreen/View/HomeScreen.swift

@@ -114,7 +114,7 @@ struct RoomCell: View {
                     .frame(width: 40, height: 40)
                     .mask(Circle())
             } else {
-                let _ = context.send(viewAction: .loadRoomAvatar(roomId: room.id))
+                let _ = context.send(viewAction: .loadRoomData(roomId: room.id))
                 Image(systemName: "person.3")
                     .frame(width: 40, height: 40)
             }
@@ -143,7 +143,7 @@ struct RoomCell: View {
     }
 
     private func roomName(_ room: HomeScreenRoom) -> String {
-        room.displayName + (room.isEncrypted ? "🛡": "")
+        room.displayName ?? room.id + (room.isEncrypted ? "🛡": "")
     }
 }
 

ElementX/Sources/Modules/Models/MockRoomModel.swift

@@ -23,6 +23,10 @@ struct MockRoomModel: RoomModelProtocol {
     let isPublic = Bool.random()
     let isEncrypted = Bool.random()
 
+    func loadDisplayName(_ completion: @escaping (Result<String, Error>) -> Void) {
+        completion(.success(displayName))
+    }
+    
     func loadAvatar(_ completion: (Result<UIImage?, Error>) -> Void) {
         completion(.success(UIImage(systemName: "wand.and.stars")))
     }

ElementX/Sources/Modules/Models/RoomModel.swift

@@ -10,6 +10,7 @@ import UIKit
 import MatrixRustSDK
 
 enum RoomModelError: Error {
+    case failedRetrievingDisplayName
     case failedRetrievingAvatar
 }
 
@@ -74,6 +75,22 @@ struct RoomModel: RoomModelProtocol {
         return URL(string: urlString)
     }
 
+    func loadDisplayName(_ completion: @escaping (Result<String, Error>) -> Void) {
+        DispatchQueue.global(qos: .background).async {
+            do {
+                let displayName = try room.displayName()
+                
+                DispatchQueue.main.async {
+                    completion(.success(displayName))
+                }
+            } catch {
+                DispatchQueue.main.async {
+                    completion(.failure(RoomModelError.failedRetrievingDisplayName))
+                }
+            }
+        }
+    }
+    
     func loadAvatar(_ completion: @escaping (Result<UIImage?, Error>) -> Void) {
         DispatchQueue.global(qos: .background).async {
             do {

ElementX/Sources/Modules/Models/RoomModelProtocol.swift

@@ -14,13 +14,13 @@ protocol RoomModelProtocol {
     var isSpace: Bool { get }
     var isEncrypted: Bool { get }
 
-    var displayName: String { get }
     var name: String? { get }
 
     var topic: String? { get }
     var lastMessage: String? { get }
 
     var avatarURL: URL? { get }
 
+    func loadDisplayName(_ completion: @escaping (Result<String, Error>) -> Void)
     func loadAvatar(_ completion: @escaping (Result<UIImage?, Error>) -> Void)
 }