Offline Support

React Native Chat SDK provides OOTB support for offline mode, which means user will be able to access and interact with chat even when the network is off. This is an opt-in feature that needs to be explicitly enabled on application level.

Features

The offline storage implementation currently offers the following features:

• Access to chat when Internet connection is disabled or low.
• Faster startup times and loading, since initial data is loaded from offline storage before performing any network requests.
• Syncing of the offline database using WebSocket events and Sync API.
• Optimistically update offline database during chat interactions, such as send message, add reaction, etc.

The following features are currently NOT implemented. They will be implemented gradually as part of minor releases in v5.

• Access to threads in offline mode.

Enable Offline Support

First and foremost, make sure to follow all steps from Migrating to v5 guide. To enable offline support, please follow the given steps:

Add @op-engineering/op-sqlite dependency.

Contemplate our dependency version compatibility table to make sure your @op-engineering/op-sqlite version are compatible with your stream-chat-react-native version.

  yarn add @op-engineering/op-sqlite
  npx pod-install

Do not wait for connectUser call to succeed.

It is important that you call the connectUser method on the chat client, before you render Chat components. But you don’t need to wait for connectUser to succeed before rendering Chat components. This is to ensure:

• Chat components have access to current user information, which is important to store/access offline data.
• In case of slow or no network access, Chat components will still load the chat data without waiting for connectUser to succeed.

const chatClient = StreamChat.getInstance('API_KEY');
const App = () => {
  const [isClientReady, setIsClientReady] = useState(false);

  useEffect(() => {
    const startChat = async () => {
      const connectPromise = chatClient.connectUser(user, tokenOrTokenProvider);
      setIsClientReady(true); // this allows components to render
      await connectPromise();
      // Any other post-connectUser logic you may have goes here.
    };
    startChat();
  }, []);

  if (!isClientReady) return null; // or some loading indicator;

  return (
    <Chat client={chatClient} enableOfflineSupport>
      ...
    </Chat>
  );
};

Add enableOfflineSupport prop on Chat component.

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

<Chat client={chatClient} enableOfflineSupport>
  ...
</Chat>;

Reset the database when signing out the user.

Since the SDK doesn’t handle app-level authentication logic, it’s the application’s responsibility to ensure the database is reset when a user gets logged out. This should generally be done before you call client.disconnectUser().

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

// Sign out logic
await SqliteClient.resetDB();
chatClient.disconnectUser();

How To Cache Images

Our SDK relies on the default caching provided by React Native (avatars, image attachments, URL preview, etc.). This default solution is far from perfect, and you might see a lot of images missing while operating the app in offline mode. We provide a convenient solution to replace all the underlying usage of the Image component using the ImageComponent prop on the Chat component. Use the ImageComponent prop to provide a custom component that handles caching and has the same API as react-native’s Image component.

There are plenty of libraries available for this purpose:

• react-native-fast-image
• react-native-progressive-fast-image
• react-native-cached-image

The following example demonstrates the usage of react-native-fast-image library to handle the caching of images in chat:

import FastImage from 'react-native-fast-image';

...

<Chat
  client={chatClient}
  enableOfflineSupport
  ImageComponent={FastImage}
/>