export const useOnClickOutside = (ref, handler) => {
  React.useEffect(() => {
    const listener = (event) => {
      if (!ref.current || ref.current.contains(event.target)) {
        return;
      }
      handler(event);
    };

    document.addEventListener('mousedown', listener);
    document.addEventListener('touchstart', listener);

    return () => {
      document.removeEventListener('mousedown', listener);
      document.removeEventListener('touchstart', listener);
    };
  }, [ref, handler]);
};

Why?

This hook allows you to detect clicks outside of a specified element.

The idea with moving this logic into a hook is so that we can easily use it across all of our components that need this kind of functionality (dropdown menus, tooltips, etc).

Usage

import React from 'react';

function App() {
    // Create a ref that we add to the element for which we want to detect outside clicks
    const ref = React.useRef();

    // State for our modal
    const [isModalOpen, setModalOpen] = React.useState(false);

    // Call hook passing in the ref and a function to call on outside click
    useOnClickOutside(ref, () => setModalOpen(false));

    return (
    <>
        {isModalOpen ? (
            <div ref={ref}>
            👋 Hey, I'm a modal. Click anywhere outside of me to close.
            </div>
        ) : (
            <button onClick={() => setModalOpen(true)}>Open Modal</button>
        )}
    </>
    );
}