AI solution for React Coding Question on BFE.dev
15. useClickOutside()

To implement the useClickOutside() hook, we need to:

1. Define a ref using the useRef() hook to store a reference to the element that we want to detect clicks outside of.
2. Define a callback function that runs when a click event is detected outside the element that we are tracking.
3. Add event listeners to detect clicks on the document once the component has been mounted using the useEffect() hook.
4. Remove event listeners when the component is unmounted using the cleanup function returned from useEffect().

Here is one possible implementation of the useClickOutside() hook:

import { useRef, useEffect } from 'react';

function useClickOutside(onClickOutside) {
  const ref = useRef(null);

  useEffect(() => {
    const handleClickOutside = (event) => {
      if (ref.current && !ref.current.contains(event.target)) {
        onClickOutside();
      }
    };

    document.addEventListener('mousedown', handleClickOutside);

    return () => {
      document.removeEventListener('mousedown', handleClickOutside);
    };
  }, [ref, onClickOutside]);

  return ref;
}

export default useClickOutside;

Then, we can use the useClickOutside() hook like this:

import { useState } from 'react';
import useClickOutside from './useClickOutside';

function Component() {
  const [isMenuOpen, setIsMenuOpen] = useState(false);

  const toggleMenu = () => {
    setIsMenuOpen((prevState) => !prevState);
  };

  const closeMenu = () => {
    setIsMenuOpen(false);
  };

  const menuRef = useClickOutside(closeMenu);

  return (
    <div>
      <button onClick={toggleMenu}>Toggle Menu</button>
      {isMenuOpen && (
        <ul ref={menuRef}>
          <li>Menu Item 1</li>
          <li>Menu Item 2</li>
          <li>Menu Item 3</li>
        </ul>
      )}
    </div>
  );
}

export default Component;

In this example, clicking the "Toggle Menu" button will show/hide a dropdown menu. When the menu is shown, the useClickOutside() hook is used to detect clicks outside the dropdown menu and close the menu accordingly.