Client

Stream Chat for React Native uses the Stream Chat client to connect to and communicate with the Stream API.

The full JavaScript client docs should be referenced for detailed information on directly using the client.

Setup

To interact with the Stream Chat API you must create a client instance and connect to the API, usually as an authenticated user.

Instantiation

The Stream Chat client, StreamChat is a dependency of stream-chat-react-native and can be imported from stream-chat. To create a client instance you can call getInstance on the client and provide and API key.

import { StreamChat } from 'stream-chat';

const client = StreamChat.getInstance('api_key');

const client = new StreamChat('api_key');

Connecting a User

To connect a user a the connectUser function should be called and provided with the user object and user_token. The user_token is typically sent from your back end when a user is authenticated.

await client.connectUser(
  {
    id: 'testUser',
    name: 'Test User',
  },
  'user_token',
);

It is recommended to not repeatedly call connectUser unnecessarily, multiple calls to connectUser will result in warnings, and attempting to call connectUser before disconnecting a current user will throw an Error.

UI Components

The Stream Chat for React Native UI components handle most interactions with the client for you after connecting with an authenticated user.

Providing the Client to the UI

To provide the client to the UI components you simply provide the client instance as the prop client to the Chat component.

import { StreamChat } from 'stream-chat';
import { Chat } from 'stream-chat-react-native';

const client = StreamChat.getInstance('api_key');

export const Screen = () => <Chat client={client}>{/** App components */}</Chat>;

The Stream Chat for React Native UI components then handle interacting with the client internally by accessing the client via context.

import { useChatContext } from 'stream-chat-react-native';

const { client } = useChatContext();

Using UI Functions

The UI provides a number of functions that interact with the client while keeping the UI state in sync using context. The contexts section details what functions are accessible. When customizing your application you should ensure you are utilizing the correct functions to keep the UI state up to date.

The sendMessage function for instance, provided by useMessageInputContext, is not the same as the sendMessage function found directly on a channel in the client. Therefore calling channel.sendMessage(messageData) will not result in a message optimistically showing in the UI, or a failed send state, instead the message will not show until it is returned by the server.

Accessing the Client Instance

There are multiple ways to access the client instance throughout your application. As mentioned you can access the client via useChatContext when inside the Chat component. This works well if you can wrap your entire application in a single Chat component and have the StreamChat instance provided throughout your app via the internal context. But if you have multiple screens that contain Chat components where a client instance is necessary you will need to access the shared instance in other ways.

You can store the client in a context you create yourself. Create your own custom class that provides it. Or using the Singleton structure you can call getInstance when required to always be returned the current instance if one exists, or create a new one otherwise.

Direct Interaction

There may be some direct interaction with the client that is required for your application. Referring to the full documentation is suggested for detailed information on client functionality. Common interactions with the client used in conjunction with the Stream Chat for React Native components have been included for convenience.

Creating a Channel

A channel must be initialized with either an id or a list of members for the channel. If you provide a list of members an id will be auto-generated on backend for the channel.

/**
 *  Channel created using a channel id
 */
const channel = client.channel(channel_type, 'channel_id', {
  name: 'My New Channel',
});

/**
 *  Channel created using a members list
 */
const channel = client.channel(channel_type, {
    members: ['userOne', 'userTwo']
    name: 'My New Channel',
});

To create a channel on the server you must call create or watch on a new channel instance. create will create the channel while watch will both create the channel and subscribe the client to updates on the channel.

await channel.watch();

await channel.create();

Disconnecting a User

To disconnect a user you can call disconnect on the client.

await client.disconnectUser();