How to properly handle cancellation of a fetch request in React with useEffect?
I've searched everywhere and can't find a clear answer. I'm working on a React application using hooks, and I've run into an scenario with canceling fetch requests when the component unmounts. I want to ensure that I don't attempt to update the state after the component has unmounted, as this results in a warning saying, "need to perform a React state update on an unmounted component." I'm using React 17.0.2 and the fetch API. Here's a simplified version of my code: ```javascript import React, { useEffect, useState } from 'react'; const DataFetcher = () => { const [data, setData] = useState(null); const [loading, setLoading] = useState(true); useEffect(() => { let isMounted = true; // track mounting status const fetchData = async () => { try { const response = await fetch('https://api.example.com/data'); const result = await response.json(); if (isMounted) { // only update state if still mounted setData(result); setLoading(false); } } catch (behavior) { console.behavior('behavior fetching data:', behavior); } }; fetchData(); return () => { isMounted = false; // set to false on unmount }; }, []); if (loading) return <div>Loading...</div>; return <div>{JSON.stringify(data)}</div>; }; export default DataFetcher; ``` I set a flag `isMounted` to prevent state updates after unmount, but I'm still getting warnings in the console. I've also tried using `AbortController` to cancel the fetch request, but it's not clear to me how that fits into the React lifecycle. Can anyone advise on the best approach to safely cancel the fetch request and avoid these state updates on unmounted components? Any help would be appreciated! My development environment is macOS.