90 lines
2.3 KiB
Markdown
90 lines
2.3 KiB
Markdown
## useDebounce Hook
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A hook that debounces the giving value.
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```jsx
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export function useDebounce(value, delay) {
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// State and setters for debounced value
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const [debouncedValue, setDebouncedValue] = useState(value);
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useEffect(
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() => {
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// Update debounced value after delay
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const handler = setTimeout(() => {
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setDebouncedValue(value);
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}, delay);
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// Cancel the timeout if value changes (also on delay change or unmount)
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// This is how we prevent debounced value from updating if value is changed ...
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// .. within the delay period. Timeout gets cleared and restarted.
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return () => {
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clearTimeout(handler);
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};
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},
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[value, delay] // Only re-call effect if value or delay changes
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);
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return debouncedValue;
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}
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// const value = useDebounce(val, 500)
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```
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## useLocation Hook
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URL location hook which fires when URL (location.pathname) changes.
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```jsx
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export function useLocation(){
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const [ location, setLocation ] = useState(window.location.pathname)
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function locListener(){
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const isSamePage = location==window.location.pathname
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//console.log("isSamePage", isSamePage)
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if(!isSamePage){
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setLocation(window.location.pathname)
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}
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}
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useEffect(() =>{
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locListener()
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window.addEventListener("location", locListener);
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// for removing repeatedly rendering
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return () =>{
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window.removeEventListener("location", locListener);
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}
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},[window.location.pathname])
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//console.log("hook", location)
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return location
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}
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// const path = useLocation()
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```
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## useWindowWidth
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A hook that listens window resizing.
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```jsx
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export function useWindowWidth() {
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const [screenSize, setScreenSize] = useState(window.innerWidth)// S | M | L
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const screenListener = () => {
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const currentSize = window.innerWidth;
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//if size (not width) is changed, then change state
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if (screenSize != currentSize) {
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setScreenSize(currentSize);
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}
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}
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useEffect(() => {
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// Once screenSize changed this will be fired
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window.addEventListener("resize", screenListener);
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// for removing repeatedly rendering
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return () => {
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window.removeEventListener("resize", screenListener);
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}
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})
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return screenSize
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}
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// const vw = useWindowWidth()
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```
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#react-hooks
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