[ PROMPT_NODE_27907 ]
Advanced Event Handler Refs
[ SKILL_DOCUMENTATION ]
## Store Event Handlers in Refs
Store callbacks in refs when used in effects that shouldn't re-subscribe on callback changes.
**Incorrect (re-subscribes on every render):**
```tsx
function useWindowEvent(event: string, handler: () => void) {
useEffect(() => {
window.addEventListener(event, handler)
return () => window.removeEventListener(event, handler)
}, [event, handler])
}
```
**Correct (stable subscription):**
```tsx
function useWindowEvent(event: string, handler: () => void) {
const handlerRef = useRef(handler)
useEffect(() => {
handlerRef.current = handler
}, [handler])
useEffect(() => {
const listener = () => handlerRef.current()
window.addEventListener(event, listener)
return () => window.removeEventListener(event, listener)
}, [event])
}
```