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https://github.com/kjanat/livedash-node.git
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Kaj Kowalski
cd05fc8648
- Fix syntax errors in skills markdown files (.github/skills, .opencode/skills) - Change typescript to tsx for code blocks with JSX - Replace ellipsis (...) in array examples with valid syntax - Separate CSS from TypeScript into distinct code blocks - Convert JavaScript object examples to valid JSON in docs - Fix enum definitions with proper comma separation
50 lines
1.2 KiB
Markdown
50 lines
1.2 KiB
Markdown
---
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title: useLatest 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, useLatest, refs, optimization
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---
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## useLatest 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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**Implementation:**
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```typescript
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function useLatest<T>(value: T) {
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const ref = useRef(value);
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useLayoutEffect(() => {
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ref.current = value;
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}, [value]);
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return ref;
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}
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```
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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 (stable effect, fresh callback):**
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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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const onSearchRef = useLatest(onSearch);
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useEffect(() => {
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const timeout = setTimeout(() => onSearchRef.current(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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