[WIP] Proof of concept for PreviewProvider

Sources/PubNubChatComponents/ManagedEntityViewModel.swift

@@ -98,7 +98,13 @@ extension PubNubManagedChannel: ManagedChannelViewModel {
       .eraseToAnyPublisher()
   }
 
-  public var messagesPublisher: AnyPublisher<Set<MessageViewModel>, Never> {
+  // This line shouldn't be changed.
+  // I got the compiler error while adopting `ManagedMessageViewModel` for my custom struct defined in SharedPreviewData.swift
+  // That's why I haven't solved it yet and created a temporary workaround. The error message says:
+  //
+  // "Reference to invalid associated type MessageViewModel of type PubNubManagedChannel"
+  //
+  public var messagesPublisher: AnyPublisher<Set<PubNubManagedMessage>, Never> {
     return publisher(for: \.messages).eraseToAnyPublisher()
   }
 

Sources/PubNubChatComponents/Previews/Previews.swift

@@ -0,0 +1,92 @@
+//
+//  File 2.swift
+//  
+//
+//  Created by Jakub Guz on 9/14/22.
+//
+
+import PubNub
+import PubNubChat
+import CoreData
+import Combine
+import UIKit
+import SwiftUI
+import ChatLayout
+
+#if canImport(SwiftUI) && DEBUG
+
+struct ExamplePreview: PreviewProvider {
+
+  static var previews: some View {
+
+    Group() {
+
+      // Light Mode
+      UIViewPreview() {
+        let view = MessageListItemCell()
+        view.configure(MyViewModel(), theme: .incomingGroupChat)
+        return view
+      }
+      .previewLayout(.fixed(width: 414, height: 140))
+      .previewDisplayName("Light Mode")
+      .preferredColorScheme(.light)
+
+      // Dark Mode
+      UIViewPreview() {
+        let view = MessageListItemCell()
+        view.configure(MyViewModel(), theme: .incomingGroupChat)
+        return view
+      }
+      .previewLayout(.fixed(width: 414, height: 140))
+      .previewDisplayName("Dark Mode")
+      .preferredColorScheme(.dark)
+
+      // RTL
+      UIViewPreview() {
+        let view = MessageListItemCell()
+        view.configure(MyViewModel(), theme: .incomingGroupChat)
+        return view
+      }
+      .environment(\.layoutDirection, .rightToLeft)
+      .previewLayout(.fixed(width: 414, height: 140))
+      .previewDisplayName("RTL")
+
+      // Accessibility
+      UIViewPreview() {
+
+        let view = MessageListItemCell()
+        view.configure(MyViewModel(), theme: .incomingGroupChat)
+        return view
+      }
+      .environment(\.sizeCategory, .accessibilityExtraLarge)
+      .previewLayout(.fixed(width: 414, height: 140))
+      .previewDisplayName("Accessibility")
+
+      UIViewControllerPreview() {
+        let vm = testChatProvider.senderMembershipsChanneListComponentViewModel()
+        let vc = vm.configuredComponentView()
+        let navv = UINavigationController(rootViewController: vc)
+
+        return navv
+      }
+      .previewDisplayName("VC")
+
+      if #available(iOS 15.0, *) {
+        UIViewControllerPreview() {
+          let vm = testChatProvider.senderMembershipsChanneListComponentViewModel()
+          let vc = vm.configuredComponentView()
+          let navv = UINavigationController(rootViewController: vc)
+
+          return navv
+
+        }
+        .previewInterfaceOrientation(.landscapeRight)
+        .previewDisplayName("VC2")
+      } else {
+        // Fallback on earlier versions
+      }
+    }
+  }
+}
+
+#endif

Sources/PubNubChatComponents/Previews/SharedPreviewData.swift

@@ -0,0 +1,186 @@
+//
+//  File 2.swift
+//  
+//
+//  Created by Jakub Guz on 9/19/22.
+//
+
+#if canImport(SwiftUI) && DEBUG
+
+import Foundation
+import PubNub
+import PubNubChat
+import CoreData
+import Combine
+
+// The idea could be creating a shared class (or something similar) that holds shared data.
+// Then it's up to you what data you would like to use in your previews. Please don't treat existing implementation very serious, it's rather a POC 
+
+// MARK: ChatProvider with in-memory storage
+
+public let testChatProvider: PubNubChatProvider = {
+
+  let chatProvider = PubNubChatProvider(
+    pubnubProvider: PubNub(configuration: PubNubConfiguration(publishKey: "...", subscribeKey: "...", userId: "JG")),
+    coreDataProvider: try! CoreDataProvider(location: .memory, flushDataOnLoad: false),
+    cacheProvider: UserDefaults.standard
+  )
+
+  let channel = PubNubChatChannel(
+    id: "CHANNEL1",
+    name: "Channel 1",
+    type: "direct",
+    status: "status",
+    details: "Channel details",
+    avatarURL: URL(string: "https://picsum/photos/200/300"),
+    updated: nil,
+    eTag: nil,
+    custom: VoidCustomData()
+  )
+
+  let user1 = PubNubChatUser(
+    id: "JG",
+    name: "JG"
+  )
+
+  let message = PubNubChatMessage(
+    id: "12345",
+    text: "Hello, world!!!",
+    pubnubUserId: "JG",
+    pubnubChannelId: "CHANNEL1"
+  )
+
+  let membership = PubNubChatMember(
+    channelId: "CHANNEL1",
+    userId: "JG"
+  )
+
+  chatProvider.dataProvider.load(users: [user1])
+  chatProvider.dataProvider.load(members: [membership])
+  chatProvider.dataProvider.load(channels: [channel])
+  chatProvider.dataProvider.load(messages: [message], processMessageActions: false)
+
+  return chatProvider
+
+}()
+
+// MARK: ManagedMessageViewModel conformance
+
+class MyViewModel: ManagedMessageViewModel {
+
+  public typealias Entity = PubNubManagedMessage
+  public typealias ChannelViewModel = PubNubManagedChannel
+  public typealias UserViewModel = PubNubManagedUser
+  public typealias MessageActionModel = PubNubManagedMessageAction
+
+  public var pubnubId: Timetoken { return 0 }
+  public var managedObjectId: NSManagedObjectID { return NSManagedObjectID() }
+
+  public func decodedContent<T: Decodable>(from: T.Type) throws -> T {
+    return try JSONDecoder().decode(T.self, from: Data())
+  }
+
+  public var messageContentTypePublisher: AnyPublisher<String, Never> {
+    Just("TEXT").eraseToAnyPublisher()
+  }
+
+  public var messageContentPublisher: AnyPublisher<Data, Never> {
+    Just(Data()).eraseToAnyPublisher()
+  }
+
+  public var messageTextPublisher: AnyPublisher<String, Never> {
+    Just(
+      "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore."
+    ).eraseToAnyPublisher()
+  }
+
+  public var messageCustomPublisher: AnyPublisher<Data, Never> {
+    Just(Data()).eraseToAnyPublisher()
+  }
+
+  public var messageDateCreatedPublisher: AnyPublisher<Date, Never> {
+    Just(Date()).eraseToAnyPublisher()
+  }
+
+  public var messageActionsPublisher: AnyPublisher<Set<PubNubManagedMessageAction>, Never> {
+    Just(Set<PubNubManagedMessageAction>()).eraseToAnyPublisher()
+  }
+
+  public var messageActions: Set<PubNubManagedMessageAction> {
+    Set<PubNubManagedMessageAction>()
+  }
+
+  public var userViewModel: PubNubManagedUser {
+
+    let user = PubNubManagedUser(context: testChatProvider.coreDataContainer.viewContext)
+    user.avatarURL = URL(string: "https://picsum.photos/100/300")
+    user.id = "JG"
+    user.name = "Jakub Jakub Jakub"
+
+    return user
+  }
+
+  public var text: String {
+    String("Text Text Text !!!")
+  }
+
+  public var channelViewModel: PubNubManagedChannel {
+    PubNubManagedChannel()
+  }
+
+  public var messageActionViewModels: Set<PubNubManagedMessageAction> {
+    Set<PubNubManagedMessageAction>()
+  }
+}
+
+// MARK: ManagedChannelViewModel conformance
+
+class MyChannelViewModel: ManagedChannelViewModel {
+
+  typealias Entity = PubNubManagedChannel
+  typealias MessageViewModel = PubNubManagedMessage
+
+  public var pubnubId: String { return String() }
+  public var managedObjectId: NSManagedObjectID { return NSManagedObjectID() }
+
+  public var channelNamePublisher: AnyPublisher<String?, Never> {
+    Just("Channel name").eraseToAnyPublisher()
+  }
+
+  public var channelDetailsPublisher: AnyPublisher<String?, Never> {
+    Just("Channel details").eraseToAnyPublisher()
+  }
+
+  public var channelAvatarUrlPublisher: AnyPublisher<URL?, Never> {
+    Just(URL(string: "https://picsum.photos/300/400")!).eraseToAnyPublisher()
+  }
+
+  public var channelTypePublisher: AnyPublisher<String, Never> {
+    Just("Default").eraseToAnyPublisher()
+  }
+  public var channelCustomPublisher: AnyPublisher<Data, Never> {
+    Just(Data()).eraseToAnyPublisher()
+  }
+
+  public var membershipPublisher: AnyPublisher<Set<PubNubManagedMember>, Never> {
+    Just(Set<PubNubManagedMember>()).eraseToAnyPublisher()
+  }
+
+  public var memberCountPublisher: AnyPublisher<Int, Never> {
+    Just(5).eraseToAnyPublisher()
+  }
+
+  public var presentMemberCountPublisher: AnyPublisher<Int, Never> {
+    Just(5).eraseToAnyPublisher()
+  }
+
+  public var messagesPublisher: AnyPublisher<Set<PubNubManagedMessage>, Never> {
+    Just(Set<PubNubManagedMessage>()).eraseToAnyPublisher()
+  }
+
+  public var oldestMessagePublisher: AnyPublisher<PubNubManagedMessage?, Never> {
+    Just(nil).eraseToAnyPublisher()
+  }
+}
+
+#endif

Sources/PubNubChatComponents/Previews/UIKitPreview.swift

@@ -0,0 +1,45 @@
+//
+//  File.swift
+//  
+//
+//  Created by Jakub Guz on 9/14/22.
+//
+
+#if canImport(SwiftUI) && DEBUG
+
+import SwiftUI
+
+struct UIViewPreview<View: UIView>: UIViewRepresentable {
+  let view: View
+
+  init(_ builder: @escaping () -> View) {
+    view = builder()
+  }
+
+  func makeUIView(context: Context) -> UIView {
+    return view
+  }
+
+  func updateUIView(_ view: UIView, context: Context) {
+    view.setContentHuggingPriority(.defaultHigh, for: .vertical)
+    view.setContentHuggingPriority(.defaultHigh, for: .horizontal)
+  }
+}
+
+struct UIViewControllerPreview<ViewController: UIViewController>: UIViewControllerRepresentable {
+  let viewController: ViewController
+
+  init(_ builder: @escaping () -> ViewController) {
+    viewController = builder()
+  }
+
+  func makeUIViewController(context: Context) -> ViewController {
+    viewController
+  }
+
+  func updateUIViewController(_ uiViewController: ViewController, context: Context) {
+
+  }
+}
+
+#endif