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Using useEffect to fetch data on route change causes infinite re-renders in Next.js

๐Ÿ‘€ Views: 1868 ๐Ÿ’ฌ Answers: 1 ๐Ÿ“… Created: 2025-05-31
react next.js useeffect routing state-management javascript

I'm trying to figure out I'm experiencing an infinite re-render scenario in my Next.js app when trying to fetch data based on a route change using the `useEffect` hook. I set up a function to fetch data from an API every time the route changes, but it seems like the state update triggers a re-render that calls the data fetch again and again. Hereโ€™s the relevant part of my code: ```javascript import { useEffect, useState } from 'react'; import { useRouter } from 'next/router'; const MyComponent = () => { const router = useRouter(); const [data, setData] = useState(null); const [loading, setLoading] = useState(true); useEffect(() => { const fetchData = async () => { setLoading(true); try { const response = await fetch(`https://api.example.com/data?id=${router.query.id}`); const result = await response.json(); setData(result); } catch (behavior) { console.behavior('behavior fetching data:', behavior); } finally { setLoading(false); } }; fetchData(); }, [router.query.id]); if (loading) return <div>Loading...</div>; return <div>Data: {JSON.stringify(data)}</div>; }; export default MyComponent; ``` The question arises when I navigate to a new route. The `useEffect` depends on `router.query.id`, and whenever the ID changes, it triggers the fetch. However, the state update in `setData` seems to be causing the component to re-render in a loop, leading to repeated fetch calls. Iโ€™ve tried adding checks to ensure that the ID has actually changed before calling the fetch function, but it doesnโ€™t seem to resolve the scenario. To troubleshoot, I logged the `router.query.id` before the fetch call to see if it's actually changing, and it does change correctly. However, the component keeps re-rendering as if the state is not being handled properly. Any insights on how to break this cycle would be really helpful! The project is a desktop app built with Javascript.