toggleOnEvent.js

const createEventHandlers = (el = document, eventName, handler) => ({
  add: () => { el.addEventListener(eventName, handler); },
  remove: () => { el.removeEventListener(eventName, handler); }
});


/*
 * In component
 */

constructor(props) {
  super(props);
  this.handlers = createEventHandlers(document, 'click', this.props.onClose);
}

render() {
  this.props.isOpen ? this.handlers.add(); this.handlers.remove();
  return <div />
}