Kebab file names

snippets/use-on-window-scroll.md

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+---
+title: React useOnWindowScroll hook
+tags: hooks,effect,event
+author: chalarangelo
+cover: planning
+firstSeen: 2021-12-08T05:00:00-04:00
+---
+
+Executes a callback whenever the window is scrolled.
+
+- Use the `useRef()` hook to create a variable, `listener`, which will hold the listener reference.
+- Use the `useEffect()` hook and `EventTarget.addEventListener()` to listen to the `'scroll'` event of the `Window` global object.
+- Use `EventTarget.removeEventListener()` to remove any existing listeners and clean up when the component unmounts.
+
+```jsx
+const useOnWindowScroll = callback => {
+  const listener = React.useRef(null);
+
+  React.useEffect(() => {
+    if (listener.current)
+      window.removeEventListener('scroll', listener.current);
+    listener.current = window.addEventListener('scroll', callback);
+    return () => {
+      window.removeEventListener('scroll', listener.current);
+    };
+  }, [callback]);
+};
+```
+
+```jsx
+const App = () => {
+  useOnWindowScroll(() => console.log(`scroll Y: ${window.pageYOffset}`));
+  return <p style={{ height: '300vh' }}>Scroll and check the console</p>;
+};
+
+ReactDOM.createRoot(document.getElementById('root')).render(
+  <App />
+);
+```