The complete guide to WebSockets with React

In this tutorial, we built a full-stack JavaScript application that uses WebSockets for real-time communication between the client (a React app) and the server (a Node.js Express app). The main feature of our application is real-time cursor tracking, which allows multiple users to see each other's cursors on the screen in real time. Here are the key takeaways from this tutorial: 1. WebSocket is a protocol that provides full-duplex communication channels over a single TCP connection. It enables real-time, bi-directional communication between web clients and servers. 2. To use WebSockets in your application, you need to set up both the client and server sides of the connection. The client initiates the connection by sending an HTTP upgrade request to the server. If the server supports WebSocket, it responds with a 101 status code and upgrades the connection to WebSocket. 3. In this tutorial, we used the react-use-websocket library to manage the WebSocket connection in our React client app. This library provides a simple hook that abstracts away many of the complexities of working with WebSockets directly. 4. To send real-time cursor updates from the client to the server, we throttled the updates using lodash.throttle. This helped reduce network traffic and improve performance by preventing the server from being overwhelmed with too many messages at once. 5. On the server side, we used the WebSocketServer class provided by the ws library to handle incoming WebSocket connections. We also implemented a simple broadcast mechanism that allows us to send updates to all connected clients simultaneously. 6. To render real-time cursors on the screen, we used perfect-cursors - a small utility library that can animate the movement of a cursor between two points. This helped create a smooth and visually appealing real-time cursor experience for our users. 7. Finally, we added a "who's online" list to our application by leveraging the user presence information maintained by Ably. This feature allowed us to easily display a textual representation of who's currently connected and their state. By following this tutorial, you should now have a good understanding of how to use WebSockets in your React applications for real-time communication between clients and servers. You can also apply the same concepts and techniques to other types of real-time applications such as chat apps, multiplayer games, or collaborative editing tools.