socket.io 4.7.4

Socket.IO is a powerful JavaScript library that enables real-time, bidirectional, and event-based communication between web clients and servers. It includes a Node.js server and a JavaScript client library for the browser (or a Node.js client), which provides a seamless API for developers to handle real-time data transmission. Socket.IO achieves high reliability with connections, even in the presence of proxies and personal firewalls, thanks to its use of Engine.IO. Importantly, it's not just a WebSocket implementation – it enhances the WebSocket protocol with additional metadata and control features, including auto-reconnection, disconnection detection, binary support, multiplexing support, and room support, among others.

Socket.IO is easy to use in various JavaScript-based server environments. You can install it via npm using the command npm install socket.io or via yarn with yarn add socket.io.

Once installed, you can implement the library in your server-side JavaScript code. Below is an example of how you might use it in a standalone Node.js server:

const io = require('socket.io')();
io.on('connection', client => {
  client.on('event', data => { /* handle data event */ });
  client.on('disconnect', () => { /* handle disconnect event */ });
});
io.listen(3000);

In the above code, io.on('connection', client => { ... }) listens for a 'connection' event (which is triggered when a client connects to the server) and then assigns event handlers for the connected client. The io.listen(3000); line indicates that the server listens on port 3000. This is just one of many ways to use Socket.IO, the library supports many other use cases and can be used in conjunction with other popular server frameworks, such as Express or Koa.

The official documentation for Socket.IO can be found at socket.io/docs. The documentation provides a comprehensive overview of Socket.IO, its APIs, and how to use it in your applications. It's an exhaustive resource guide which also covers various implementation details, from basic usage and installation instructions to detailed explanations of Socket.IO's advanced features. All developers, regardless of experience level, would find the documentation helpful for their Socket.IO-based development needs.