Скачать или смотреть Managing WebSocket Connections in React with useEffect for Clean Unmounting

Learn how to properly manage WebSocket connections in React using useEffect and useRef to avoid memory leaks and duplicate messages.
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This video is based on the question https://stackoverflow.com/q/79540619/ asked by the user 'Sandro Tushurashvili' ( https://stackoverflow.com/u/30079156/ ) and on the answer https://stackoverflow.com/a/79540638/ provided by the user 'Nancy Gupta' ( https://stackoverflow.com/u/11036778/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

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Introduction

Handling WebSocket connections in React requires careful management to avoid issues like persistent open connections or duplicate messages when components unmount or remount.

This guide explains how to properly manage WebSocket lifecycle in React using hooks.



The Problem

A common approach to opening a WebSocket inside a useEffect looks like this:

[[See Video to Reveal this Text or Code Snippet]]

However, this can lead to:

WebSocket connections persisting even after the component unmounts

Receiving duplicate messages when returning to the page

These happen because of improper cleanup or multiple connections opened without closing previous ones.



Proper WebSocket Management in React

Using useRef to Track the WebSocket Instance

To gracefully manage the connection, store the WebSocket instance in a useRef variable. This enables:

Easy access to the current socket outside the effect scope

Proper closing of any existing connection before opening a new one

Updated Hook Example

[[See Video to Reveal this Text or Code Snippet]]

Key Takeaways

Always close existing WebSocket connections before creating new ones when url changes.

Close connections when the component unmounts by returning a cleanup function in useEffect.

Use useRef to keep a persistent reference to the WebSocket, allowing proper control over its lifecycle.



Conclusion

By tracking your WebSocket with useRef and ensuring cleanup on unmount or when dependencies change, you can prevent memory leaks and duplicate messages. This pattern leads to clean, maintainable real-time React applications.



Pro Tip: Consider handling additional events like onerror and onclose for enhanced robustness.