Getting Started

The UI Components library includes pre-built Android Views to easily load and display data from the Stream Chat API.

First things first, you have to initialize the ChatClient in your application. This is the main entry point for all the chat functionalities. Typically you would initialize the ChatClient in your Application class.

ChatClient.Builder("YOUR_API_KEY", context)
    // Set other configurations
    .build()

// Static reference to initialised client
val client = ChatClient.instance()

Connecting a User

Once you have the ChatClient initialised, you can connect a user to the chat.

Let's say you have a User model:

val user = User(
    id = "bender",
    name = "Bender",
    image = "https://bit.ly/321RmWb",
)

Then you can call the connectUser method with either a JWT token or a TokenProvider to connect the user to the chat.

Here is an example of how to connect a user to the chat with a JWT token:

val token = "CHAT_USER_TOKEN"
client.connectUser(user, token).enqueue { result ->
    when (result) {
        is Result.Success -> {
            // Logged in
            val loggedInUser: User = result.value.user
            val connectionId: String = result.value.connectionId
        }
        is Result.Failure -> {
            // Handle error
            val error = result.value
        }
    }
}

Here is an example of how to connect a user to the chat with a TokenProvider:

val tokenProvider = object : TokenProvider {
    // Make a request to your backend to generate a valid token for the user.
    // It is expected that "yourTokenService.getToken" never throws an exception.
    // If the token cannot be loaded, it should return an empty string.
    override fun loadToken(): String = yourTokenService.getToken(user)
}
client.connectUser(user, tokenProvider).enqueue { /* ... */ }

Lifecycle Management

Most commonly, you would want to call ChatClient#connectUser when the user logs in and ChatClient#disconnect when the user logs out.

To handle those scenarios, you could define some UserRepository in your application that would be responsible for storing the logged-in user until the user logs out.

interface UserRepository {
    fun getCurrentUser(): User?
    fun setCurrentUser(user: User)
    fun clearCurrentUser()
}

Then when the user logs in, you would call ChatClient#connectUser and store the user in the UserRepository.

val user = User(/* ... */)
client.connectUser(user, tokenProvider).enqueue { result ->
    if (result is Result.Success) {
        userRepository.setCurrentUser(result.value.user)
    } else if (result is Result.Failure) {
        // Handle error
    }
}

When the user logs out, you would call ChatClient#disconnect and clear the user from the UserRepository.

client.disconnect().enqueue { result ->
    userRepository.clearCurrentUser()
    // Handle result
}

Please note that you should also call ChatClient#connectUser when the Application restarts after a process death and there is a logged-in user in the UserRepository.

val user = userRepository.getCurrentUser()
if (user != null) {
    client.connectUser(user, tokenProvider).enqueue { /* ... */ }
}

UI Components

Channels Screen	Messages Screen

This library builds on top of the offline library, and provides ViewModels for most Views to easily populate them with data and handle input events.

The sample app showcases the UI components in action.

See the individual pages of the components to learn more about them.

Channel components:

• Channel List Screen
• Channel List
• Channel List Header

Message components:

• Message List Screen
• Message List
• Message List Header
• Message Composer
• System Attachments Picker

Utility components:

• Pinned Message List
• Search Views
• Attachment Gallery

Checklist

For a successful integration of our UI Components, follow these steps:

1. Dependency. Add the dependency to your app, as described on the Dependencies page.
2. Set up the ChatClient. Learn how to initialize the ChatClient in the Chat Client documentation.
3. Handle user connection. Read how to connect a user in the Connecting the User guide and learn about User Tokens in the Tokens and Authentication guide.
4. State and Offline. Using the StatePlugin is mandatory if you want to use our UI Components. Read the State Overview page for more information. Also, consider adding offline support for better UX.
5. Theme. Since this library uses Material elements, make sure that you use a Material theme in your application before adding the components. This means that your app's theme should extend a theme from Theme.MaterialComponents, and not Theme.AppCompat. Find a correct example below. If you want to keep using an AppCompat theme for styling, you can inherit from a Bridge Theme to support using Material based components.

<style name="AppTheme" parent="Theme.MaterialComponents.DayNight.NoActionBar">

ViewModels

Most UI components come with their own ViewModels. These are used to easily connect them to the client to fetch data and perform actions.

These are Jetpack ViewModels, so they allow the components to retain data across configuration changes. It's your responsibility to create these in the correct scope, usually in a Fragment or Activity.

For example, if you've added a MessageListView to your layout, you can create a corresponding ViewModel like this:

// 1
val factory = MessageListViewModelFactory(cid = "messaging:123")
// 2
val viewModel: MessageListViewModel by viewModels { factory }
// 3
viewModel.bindView(messageListView, viewLifecycleOwner)

// 1
ViewModelProvider.Factory factory = new MessageListViewModelFactory
        .Builder()
        .cid("messaging:123")
        .build();
ViewModelProvider provider = new ViewModelProvider(this, factory);
// 2
MessageListViewModel viewModel = provider.get(MessageListViewModel.class);
// 3
MessageListViewModelBinding.bind(viewModel, messageListView, getViewLifecycleOwner());

1. Create the ViewModel factory, providing any necessary parameters.
2. Fetch a ViewModel with Android ViewModel APIs, passing in the factory to be used.
3. Call the bindView method of the SDK to connect the View and ViewModel, passing in the appropriate LifecycleOwner.

bindView performs two-way binding: it sets up observers that push data from the ViewModel to the View, and sets up listeners that forward input events from the View to the ViewModel.

You can learn more about setting up each UI component on their individual documentation pages.

Sample App

The UI Components sample app is an open source, fully functional messaging application. It features threads, reactions, typing indicators, optimistic UI updates and offline storage. All built on top of our UI components.

Customization

The UI components offer customization options via XML attributes as well as instance methods. You can check the individual pages of the components for more details about this. Components can also be customized globally via themes and style transformations. The Theming page describes all the available styling options for the SDK in detail.

You can also use the ChatUI object to customize the behavior of the UI Components. For example, it allows you to override fonts, add your own URL signing logic, or add custom avatar loading logic.