40 lines
1.0 KiB
Markdown
40 lines
1.0 KiB
Markdown
---
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title: useEffectEvent for Stable Callback Refs
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impact: LOW
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impactDescription: prevents effect re-runs
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tags: advanced, hooks, useEffectEvent, refs, optimization
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---
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## useEffectEvent for Stable Callback Refs
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Access latest values in callbacks without adding them to dependency arrays. Prevents effect re-runs while avoiding stale closures.
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**Incorrect (effect re-runs on every callback change):**
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```tsx
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function SearchInput({ onSearch }: { onSearch: (q: string) => void }) {
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const [query, setQuery] = useState('')
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useEffect(() => {
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const timeout = setTimeout(() => onSearch(query), 300)
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return () => clearTimeout(timeout)
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}, [query, onSearch])
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}
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```
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**Correct (using React's useEffectEvent):**
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```tsx
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import { useEffectEvent } from 'react';
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function SearchInput({ onSearch }: { onSearch: (q: string) => void }) {
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const [query, setQuery] = useState('')
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const onSearchEvent = useEffectEvent(onSearch)
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useEffect(() => {
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const timeout = setTimeout(() => onSearchEvent(query), 300)
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return () => clearTimeout(timeout)
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}, [query])
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}
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```
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