Add useOnGlobalEvent

snippets/useOnGlobalEvent.md

@@ -0,0 +1,50 @@
+---
+title: useOnGlobalEvent
+tags: hooks,effect,intermediate
+firstSeen: 2021-12-22T05:00:00-04:00
+---
+
+Executes a callback whenever an event occurs on the global object.
+
+- Use the `useRef()` hook to create a variable, `listener`, which will hold the listener reference.
+- Use the `useRef()` hook to create a variable that will hold the previous values of the `type` and `options` arguments.
+- Use the `useEffect()` hook and `EventTarget.addEventListener()` to listen to the given event `type` on the `window` global object.
+- Use `EventTarget.removeEventListener()` to remove any existing listeners and clean up when the component unmounts.
+
+```jsx
+const useOnGlobalEvent = (type, callback, options) => {
+  const listener = React.useRef(null);
+  const previousProps = React.useRef({ type, options });
+
+  React.useEffect(() => {
+    const { type: previousType, options: previousOptions } = previousProps;
+
+    if (listener.current) {
+      window.removeEventListener(
+        previousType,
+        listener.current,
+        previousOptions
+      );
+    }
+
+    listener.current = window.addEventListener(type, callback, options);
+    previousProps.current = { type, options };
+
+    return () => {
+      window.removeEventListener(type, listener.current, options);
+    };
+  }, [callback, type, options]);
+};
+```
+
+```jsx
+const App = () => {
+  useOnGlobalEvent('mousemove', e => {
+    console.log(`(${e.x}, ${e.y})`);
+  });
+
+  return <p>Move your mouse around</p>;
+};
+
+ReactDOM.render(<App />, document.getElementById('root'));
+```