| 1 | --- |
| 2 | title: useEffectEvent for Stable Callback Refs |
| 3 | impact: LOW |
| 4 | impactDescription: prevents effect re-runs |
| 5 | tags: advanced, hooks, useEffectEvent, refs, optimization |
| 6 | --- |
| 7 | |
| 8 | ## useEffectEvent for Stable Callback Refs |
| 9 | |
| 10 | Access latest values in callbacks without adding them to dependency arrays. Prevents effect re-runs while avoiding stale closures. |
| 11 | |
| 12 | **Incorrect (effect re-runs on every callback change):** |
| 13 | |
| 14 | ```tsx |
| 15 | function SearchInput({ onSearch }: { onSearch: (q: string) => void }) { |
| 16 | const [query, setQuery] = useState('') |
| 17 | |
| 18 | useEffect(() => { |
| 19 | const timeout = setTimeout(() => onSearch(query), 300) |
| 20 | return () => clearTimeout(timeout) |
| 21 | }, [query, onSearch]) |
| 22 | } |
| 23 | ``` |
| 24 | |
| 25 | **Correct (using React's useEffectEvent):** |
| 26 | |
| 27 | ```tsx |
| 28 | import { useEffectEvent } from 'react'; |
| 29 | |
| 30 | function SearchInput({ onSearch }: { onSearch: (q: string) => void }) { |
| 31 | const [query, setQuery] = useState('') |
| 32 | const onSearchEvent = useEffectEvent(onSearch) |
| 33 | |
| 34 | useEffect(() => { |
| 35 | const timeout = setTimeout(() => onSearchEvent(query), 300) |
| 36 | return () => clearTimeout(timeout) |
| 37 | }, [query]) |
| 38 | } |
| 39 | ``` |
| 40 |