Nicholai
75168f7678
structure: state/CURRENT.md — 2-4 line session state (rewritten each session) events/ — json event bus (pull-based, optional context) persistent/ — important decisions (one doc per decision) emit — helper script for emitting events
40 lines
1.0 KiB
Markdown
40 lines
1.0 KiB
Markdown
---
|
|
title: useEffectEvent for Stable Callback Refs
|
|
impact: LOW
|
|
impactDescription: prevents effect re-runs
|
|
tags: advanced, hooks, useEffectEvent, refs, optimization
|
|
---
|
|
|
|
## useEffectEvent for Stable Callback Refs
|
|
|
|
Access latest values in callbacks without adding them to dependency arrays. Prevents effect re-runs while avoiding stale closures.
|
|
|
|
**Incorrect (effect re-runs on every callback change):**
|
|
|
|
```tsx
|
|
function SearchInput({ onSearch }: { onSearch: (q: string) => void }) {
|
|
const [query, setQuery] = useState('')
|
|
|
|
useEffect(() => {
|
|
const timeout = setTimeout(() => onSearch(query), 300)
|
|
return () => clearTimeout(timeout)
|
|
}, [query, onSearch])
|
|
}
|
|
```
|
|
|
|
**Correct (using React's useEffectEvent):**
|
|
|
|
```tsx
|
|
import { useEffectEvent } from 'react';
|
|
|
|
function SearchInput({ onSearch }: { onSearch: (q: string) => void }) {
|
|
const [query, setQuery] = useState('')
|
|
const onSearchEvent = useEffectEvent(onSearch)
|
|
|
|
useEffect(() => {
|
|
const timeout = setTimeout(() => onSearchEvent(query), 300)
|
|
return () => clearTimeout(timeout)
|
|
}, [query])
|
|
}
|
|
```
|