Added possiblity to inject view models

Author: martinmitrevski

Sources/StreamChatSwiftUI/ChatChannel/ChatChannelView.swift

@@ -19,12 +19,13 @@ public struct ChatChannelView<Factory: ViewFactory>: View, KeyboardReadable {
 
     public init(
         viewFactory: Factory,
+        viewModel: ChatChannelViewModel? = nil,
         channelController: ChatChannelController,
         messageController: ChatMessageController? = nil,
         scrollToMessage: ChatMessage? = nil
     ) {
         _viewModel = StateObject(
-            wrappedValue: ViewModelsFactory.makeChannelViewModel(
+            wrappedValue: viewModel ?? ViewModelsFactory.makeChannelViewModel(
                 with: channelController,
                 messageController: messageController,
                 scrollToMessage: scrollToMessage

Sources/StreamChatSwiftUI/ChatChannelList/ChatChannelListView.swift

@@ -21,12 +21,13 @@ public struct ChatChannelListView<Factory: ViewFactory>: View {
 
     public init(
         viewFactory: Factory,
+        viewModel: ChatChannelListViewModel? = nil,
         channelListController: ChatChannelListController? = nil,
         title: String = "Stream Chat",
         onItemTap: ((ChatChannel) -> Void)? = nil,
         selectedChannelId: String? = nil
     ) {
-        let channelListVM = ViewModelsFactory.makeChannelListViewModel(
+        let channelListVM = viewModel ?? ViewModelsFactory.makeChannelListViewModel(
             channelListController: channelListController,
             selectedChannelId: selectedChannelId
         )

Sources/StreamChatSwiftUI/ChatChannelList/ChatChannelListViewModel.swift

@@ -20,7 +20,7 @@ open class ChatChannelListViewModel: ObservableObject, ChatChannelListController
     /// The maximum number of images that combine to form a single avatar
     private let maxNumberOfImagesInCombinedAvatar = 4
 
-    private var controller: ChatChannelListController!
+    private var controller: ChatChannelListController?
 
     /// Used when screen is shown from a deeplink.
     private var selectedChannelId: String?
@@ -30,6 +30,8 @@ open class ChatChannelListViewModel: ObservableObject, ChatChannelListController
 
     private var messageSearchController: ChatMessageSearchController?
 
+    private var timer: Timer?
+    
     /// Controls loading the channels.
     @Atomic private var loadingNextChannels: Bool = false
 
@@ -121,15 +123,15 @@ open class ChatChannelListViewModel: ObservableObject, ChatChannelListController
     ///
     /// - Parameter index: the currently displayed index.
     public func checkForChannels(index: Int) {
-        if index < controller.channels.count - 10 {
+        if index < controller?.channels.count ?? 0 - 10 {
             return
         }
 
         if _loadingNextChannels.compareAndSwap(old: false, new: true) {
-            controller.loadNextChannels { [weak self] _ in
+            controller?.loadNextChannels { [weak self] _ in
                 guard let self = self else { return }
                 self.loadingNextChannels = false
-                self.channels = self.controller.channels
+                self.updateChannels()
             }
         }
     }
@@ -238,26 +240,30 @@ open class ChatChannelListViewModel: ObservableObject, ChatChannelListController
     }
 
     private func makeDefaultChannelListController() {
+        guard let currentUserId = chatClient.currentUserId else {
+            observeClientIdChange()
+            return
+        }
         controller = chatClient.channelListController(
-            query: .init(filter: .containMembers(userIds: [chatClient.currentUserId!]))
+            query: .init(filter: .containMembers(userIds: [currentUserId]))
         )
     }
 
     private func setupChannelListController() {
-        controller.delegate = self
+        controller?.delegate = self
 
-        channels = controller.channels
+        updateChannels()
 
         loading = true
-        controller.synchronize { [weak self] error in
+        controller?.synchronize { [weak self] error in
             guard let self = self else { return }
             self.loading = false
             if error != nil {
                 // handle error
                 self.channelAlertType = .error
             } else {
                 // access channels
-                self.channels = self.controller.channels
+                self.updateChannels()
                 self.checkForDeeplinks()
             }
         }
@@ -296,9 +302,30 @@ open class ChatChannelListViewModel: ObservableObject, ChatChannelListController
         } else {
             messageSearchController = nil
             searchResults = []
-            channels = controller.channels
+            updateChannels()
         }
     }
+    
+    private func observeClientIdChange() {
+        timer?.invalidate()
+        timer = Timer.scheduledTimer(withTimeInterval: 1.0, repeats: true, block: { [weak self] _ in
+            guard let self = self else { return }
+            if self.chatClient.currentUserId != nil {
+                self.stopTimer()
+                self.makeDefaultChannelListController()
+                self.setupChannelListController()
+            }
+        })
+    }
+    
+    private func stopTimer() {
+        timer?.invalidate()
+        timer = nil
+    }
+    
+    private func updateChannels() {
+        channels = controller?.channels ?? LazyCachedMapCollection<ChatChannel>()
+    }
 }
 
 /// Enum for the type of alert presented in the channel list view.