Use socket.io with React, in hooks (React v16.8+).

Usage

Installation

$ yarn add use-socketio

In your code

useSocket hook

Listen to a specific event and trigger the according callback everytime there's one. This hooks doesn't trigger a rerender. You have to manage it yourself.

import { SocketIOProvider, useSocket } from "use-socketio";

const Twitter = () => {
  const [tweets, setTweet] = useState([]);

  const { socket, subscribe, unsubscribe } = useSocket("tweet", newTweet =>
    setTweet([newTweet, ...tweets])
  );

  return tweets.length ? (
    <ul>
      {tweets.map(tweet => (
        <li key={tweet.id}>{tweet.text}</li>
      ))}
    </ul>
  ) : (
    <p>Actually waiting for the websocket server...</p>
  );
};

const App = () => (
  <SocketIOProvider url="http://localhost:3000" opts={socketIoOptions}>
    <Twitter />
  </SocketIOProvider>
);

The socketio options to pass to the provider are available here: https://socket.io/docs/client-api/#new-Manager-url-options.

useLastMessage hook

Listen to the latest message received on a specific event name. This hook triggers a rerender so you don't have to.

import { SocketIOProvider, useLastMessage } from "use-socketio";

const Twitter = () => {
  const { data: lastMessage, socket, subscribe, unsubscribe } = useLastMessage(
    "tweet"
  );

  return <p>{lastMessage || "Waiting for some tweets"}</p>;
};

const App = () => (
  <SocketIOProvider url="http://localhost:3000">
    <Twitter />
  </SocketIOProvider>
);

Running some code

This project is built in typescript and provides an example of the hooks previously mentioned.

To run the example locally, you have to:

• clone the repo by running $ git clone https://github.com/mfrachet/use-socketio
• installing the project dependencies by running $ yarn install inside the directory
• In one terminal, run $ yarn start:test-server. This will start a nodejs server with a socketio server
• In another terminal, run $ yarn start. This will start a web application interacting with the server
• (Optionally) you can run the E2E test suites by opening another (a third) terminal and run $ yarn e2e