Implemented persisting login in the demo app

Author: martinmitrevski

DemoAppSwiftUI/AppDelegate.swift

@@ -66,11 +66,23 @@ class AppDelegate: NSObject, UIApplicationDelegate {
             messageListConfig: MessageListConfig(dateIndicatorPlacement: .messageList)
         )
         streamChat = StreamChat(chatClient: chatClient, utils: utils)
+        
+        let credentials = UnsecureRepository.shared.loadCurrentUser()
+        if let credentials, let token = try? Token(rawValue: credentials.token)  {
+            chatClient.connectUser(
+                userInfo: .init(
+                    id: credentials.id,
+                    name: credentials.name,
+                    imageURL: credentials.avatarURL
+                ),
+                token:  token
+            )
+        }
 
-        DispatchQueue.main.asyncAfter(deadline: .now() + 2.5) {
+        DispatchQueue.main.asyncAfter(deadline: .now() + 2.0) {
             withAnimation {
-                if AppState.shared.userState == .launchAnimation {
-                    AppState.shared.userState = .notLoggedIn
+                if AppState.shared.userState == .launchAnimation {                    
+                    AppState.shared.userState = credentials == nil ? .notLoggedIn : .loggedIn
                 }
             }
         }

DemoAppSwiftUI/CustomChannelHeader.swift

@@ -86,8 +86,12 @@ struct CustomChannelModifier: ChannelListHeaderViewModifier {
                     message: Text("Are you sure you want to sign out?"),
                     primaryButton: .destructive(Text("Sign out")) {
                         withAnimation {
-                            chatClient.disconnect {}
-                            AppState.shared.userState = .notLoggedIn
+                            chatClient.disconnect {
+                                UnsecureRepository.shared.removeCurrentUser()
+                                DispatchQueue.main.async {
+                                    AppState.shared.userState = .notLoggedIn
+                                }
+                            }
                         }
                     },
                     secondaryButton: .cancel()

DemoAppSwiftUI/DemoUser.swift

@@ -8,7 +8,7 @@ public let apiKeyString = "zcgvnykxsfm8"
 public let applicationGroupIdentifier = "group.io.getstream.iOS.ChatDemoAppSwiftUI"
 public let currentUserIdRegisteredForPush = "currentUserIdRegisteredForPush"
 
-public struct UserCredentials {
+public struct UserCredentials: Codable {
     public let id: String
     public let name: String
     public let avatarURL: URL

DemoAppSwiftUI/LoginViewModel.swift

@@ -34,6 +34,7 @@ class LoginViewModel: ObservableObject {
             DispatchQueue.main.async { [weak self] in
                 withAnimation {
                     self?.loading = false
+                    UnsecureRepository.shared.save(user: credentials)
                     AppState.shared.userState = .loggedIn
                 }
             }

DemoAppSwiftUI/UserRepository.swift

@@ -0,0 +1,62 @@
+//
+// Copyright © 2023 Stream.io Inc. All rights reserved.
+//
+
+import StreamChat
+import Foundation
+
+protocol UserRepository {
+    
+    func save(user: UserCredentials)
+        
+    func loadCurrentUser() -> UserCredentials?
+    
+    func removeCurrentUser()
+}
+
+//NOTE: This is just for simplicity. User data shouldn't be kept in `UserDefaults`.
+final class UnsecureRepository: UserRepository {
+    enum Key: String, CaseIterable {
+        case user = "stream.chat.user"
+    }
+
+    private let defaults: UserDefaults
+
+    private init(defaults: UserDefaults = UserDefaults.standard) {
+        self.defaults = defaults
+    }
+
+    private func set(_ value: Any?, for key: Key) {
+        defaults.set(value, forKey: key.rawValue)
+    }
+
+    private func get<T>(for key: Key) -> T? {
+        defaults.object(forKey: key.rawValue) as? T
+    }
+    
+    static let shared = UnsecureRepository()
+
+    func save(user: UserCredentials) {
+        let encoder = JSONEncoder()
+        if let encoded = try? encoder.encode(user) {
+            set(encoded, for: .user)
+        }
+    }
+
+    func loadCurrentUser() -> UserCredentials? {
+        if let savedUser: Data = get(for: .user) {
+            let decoder = JSONDecoder()
+            do {
+                let loadedUser = try decoder.decode(UserCredentials.self, from: savedUser)
+                return loadedUser
+            } catch {
+                log.error("Error while decoding user")
+            }
+        }
+        return nil
+    }
+    
+    func removeCurrentUser() {
+        defaults.set(nil, forKey: Key.user.rawValue)
+    }
+}

StreamChatSwiftUI.xcodeproj/project.pbxproj

@@ -32,6 +32,7 @@
 		8402EAD4282BFCCA00CCA696 /* UserCredentials.swift in Sources */ = {isa = PBXBuildFile; fileRef = 8402EAD3282BFCCA00CCA696 /* UserCredentials.swift */; };
 		840A3F3828193AB20084E9CC /* ChatChannelInfoView_Tests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 840A3F3728193AB20084E9CC /* ChatChannelInfoView_Tests.swift */; };
 		8413D90227A9654600A89432 /* SearchResultsView_Tests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 8413D90127A9654600A89432 /* SearchResultsView_Tests.swift */; };
+		8417AE922ADEDB6400445021 /* UserRepository.swift in Sources */ = {isa = PBXBuildFile; fileRef = 8417AE912ADEDB6400445021 /* UserRepository.swift */; };
 		841B2EF4278DB9E500ED619E /* MessageListHelperViews.swift in Sources */ = {isa = PBXBuildFile; fileRef = 841B2EF3278DB9E500ED619E /* MessageListHelperViews.swift */; };
 		841B2EF6278F108700ED619E /* MessageReadIndicatorView_Tests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 841B2EF5278F108700ED619E /* MessageReadIndicatorView_Tests.swift */; };
 		841B64C427744DB60016FF3B /* ComposerModels.swift in Sources */ = {isa = PBXBuildFile; fileRef = 841B64C327744DB60016FF3B /* ComposerModels.swift */; };
@@ -445,6 +446,7 @@
 		8402EAD3282BFCCA00CCA696 /* UserCredentials.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = UserCredentials.swift; sourceTree = "<group>"; };
 		840A3F3728193AB20084E9CC /* ChatChannelInfoView_Tests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ChatChannelInfoView_Tests.swift; sourceTree = "<group>"; };
 		8413D90127A9654600A89432 /* SearchResultsView_Tests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SearchResultsView_Tests.swift; sourceTree = "<group>"; };
+		8417AE912ADEDB6400445021 /* UserRepository.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = UserRepository.swift; sourceTree = "<group>"; };
 		841B2EF3278DB9E500ED619E /* MessageListHelperViews.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MessageListHelperViews.swift; sourceTree = "<group>"; };
 		841B2EF5278F108700ED619E /* MessageReadIndicatorView_Tests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MessageReadIndicatorView_Tests.swift; sourceTree = "<group>"; };
 		841B64C327744DB60016FF3B /* ComposerModels.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ComposerModels.swift; sourceTree = "<group>"; };
@@ -1010,6 +1012,7 @@
 				8465FDDC2747A14700AF091E /* CustomComposerAttachmentView.swift */,
 				84335013274BAB15007A1B81 /* ViewFactoryExamples.swift */,
 				84FF723E2782FB2E006E26C8 /* iMessagePocView.swift */,
+				8417AE912ADEDB6400445021 /* UserRepository.swift */,
 				84EDBC36274FE5CD0057218D /* Localizable.strings */,
 				8465FCCA27468B7500AF091E /* Info.plist */,
 				8465FCC227468B6A00AF091E /* Assets.xcassets */,
@@ -2181,6 +2184,7 @@
 				8465FCDA274694D200AF091E /* AppDelegate.swift in Sources */,
 				8465FCD8274694D200AF091E /* LaunchScreen.swift in Sources */,
 				84B288CF274C545900DD090B /* CreateGroupViewModel.swift in Sources */,
+				8417AE922ADEDB6400445021 /* UserRepository.swift in Sources */,
 				84FF723F2782FB2E006E26C8 /* iMessagePocView.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;