Get started with PubNub Chat Components for iOS

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See how you can get a 1:1 chat app quickly up and running.

You will download a sample iOS app that uses two PubNub Chat Components for iOS: MessageInput and MessageList. Then, you'll run the app and send your first message by typing it in the message input field. The messages will pile up on the screen as you send them.

Prerequisites

• Xcode (>= Xcode 13)
• git

Tools used

This guide uses PubNub Swift SDK (>= 4.1.2) for chat components and UIKit as the UI Toolkit.

Steps

Follow the steps to get your PubNub keys, clone the sample iOS project files with chat components, and run the app to send your first message.

Create a PubNub account

Before you start, you need to obtain Publish and Subscribe Keys for your chat app. You need them to initialize the PubNub object in your app to send and receive messages through the PubNub Network. To get both keys, sign in or create an account on the Admin Portal. The autogenerated Demo Keyset in My First App already contains the configuration required to complete this guide.

Clone a sample chat app with components

Clone the chat-components-ios-examples repository.

1git clone git@github.com:pubnub/chat-components-ios-examples.git

If you're authenticated into Xcode with your GitHub account, you can also open the project directly from GitHub using the Open in Xcode button.

Configure PubNub keys

1. Once you've cloned the repository, open the getting-started project in Xcode.

2. Inside SceneDelegate, replace both PUBNUB_PUBLISH_KEY and PUBNUB_SUBSCRIBE_KEY with your Publish and Subscribe Keys from your PubNub account in the Admin Portal:

   1let PUBNUB_PUBLISH_KEY = "myPublishKey"
   2let PUBNUB_SUBSCRIBE_KEY = "mySubscribeKey"

The rest of the configuration is already provided:

• To associate a sender/current user with the PubNub messages, it's required to configure the userId parameter that stands for Universally Unique Identifier and refers to your user ID in the database. The app already sets userId in SceneDelegate using the pubnubConfiguration property. Both publishKey and subscribeKey parameters will use PUBNUB_PUBLISH_KEY and PUBNUB_SUBSCRIBE_KEY defined in the previous step.

  1lazy var pubnubConfiguration = {
  2  return PubNubConfiguration(
  3    publishKey: PUBNUB_PUBLISH_KEY,
  4    subscribeKey: PUBNUB_SUBSCRIBE_KEY,
  5    userId: "myFirstUser"
  6  )
  7}()

  userId

  For simplicity, the getting started app sets a static userId. However, if you implement chat in your app, you should generate a userId per user, device, and server and reuse it for their lifetime. Using separate User IDs in real-life apps is particularly important as it impacts your overall billing and the way your app works.

• The app calls ChatProvider which initializes all the data components. These components are responsible for providing data to UI, setting the default theme, and communicating with the PubNub service. ChatProvider is used to facilitate the majority of the functionality provided by PubNub Chat Components for iOS.

  1let provider = PubNubChatProvider(
  2  pubnubProvider: PubNub(configuration: pubnubConfiguration)
  3)

  Inside the scene(_:willConnectTo:options:) method of SceneDelegate, ChatProvider is initialized by passing in PubNubConfiguration. To learn more about this SceneDelegate method, see Apple's official documentation.

• As part of initialization, ChatProvider configures the default CoreData instance. In SceneDelegate, you can use the preloadData(_:) method to include any predefined data that should be added before using the chat components.

  1func preloadData(_ chatProvider: PubNubChatProvider, completion: @escaping () -> Void) {
  2  // Creates a user object with userId
  3  let user = PubNubChatUser(
  4    id: chatProvider.pubnubConfig.userId,
  5    name: "myFirstUser",
  6    avatarURL: URL(string: "https://picsum.photos/seed/\(chatProvider.pubnubConfig.userId)/200")
  7  )
  8
  
  9  // Creates a channel object
  10  let channel = PubNubChatChannel(
  11    id: defaultChannelId,
  12    name: "Default",
  13    type: "direct",
  14    avatarURL: URL(string: "https://picsum.photos/seed/\(defaultChannelId)/200")
  15  )
  16
  
  17  // Creates a membership between the user and the channel for subscription purposes
  18  let membership = PubNubChatMember(channel: channel, user: user)
  19
  
  20  // Subscribes to the default channel
  21  chatProvider.pubnubProvider.subscribe(.init(channels: [defaultChannelId], withPresence: true))
  22
  
  23  // Fills the database with the user, channel, and memberships data
  24  chatProvider.dataProvider.load(members: [membership], completion: completion)
  25}

  show all 25 lines

  ChatProvider can be stored at anytime using the corresponding load() methods for each of the object data types:

  • load(channels:)
  • load(users:)
  • load(members:)
  • load(messages:)

• The scene(_:willConnectTo:options:) method inside SceneDelegate finishes by loading the MessageList component as the default (root) View Controller.

  1func setupRootView(windowScene: UIWindowScene) {
  2  // Creates the default ChannelList and MemberList component view models
  3  guard let channelListViewModel = chatProvider?.senderMembershipsChanneListComponentViewModel(),
  4        let messageListViewModel = try? chatProvider?.messageListComponentViewModel(pubnubChannelId: defaultChannelId) else {
  5    preconditionFailure("Could not create intial view models")
  6  }
  7  
  8  // Creates the navigation structure
  9  let navigation = UINavigationController()
  10
  
  11  // Loads the MessageList as the root view, but allows for the ChannelList to be the previous view
  12  navigation.viewControllers = [
  13    channelListViewModel.configuredComponentView(),
  14    messageListViewModel.configuredComponentView()
  15  ]
  16
  
  17  // Sets the component as the root view controller
  18  let window = UIWindow(windowScene: windowScene)
  19  window.rootViewController = navigation
  20  self.window = window
  21  window.makeKeyAndVisible()
  22}

  show all 22 lines

  To make the application easier to use, the ChannelList component is also loaded as the previous View Controller in the app's navigation hierarchy. This is visualized by the Back button inside the navigation bar of the MessageList component that you will see once the app is up and running.

Run the chat app

Choose a simulator and run the getting-started app.

Send your first message

When your application opens up, type and send your first message. The messages will pile up on the screen as you send them.

To verify that the app is connected to the PubNub Network, mock a real-live chat conversation with myFirstUser. Open the app in a new simulator, send a message from one simulator and reply to it from another.