Rocket.Chat/app/ui-utils/client/lib/fireGlobalEvent.js

import { Tracker } from 'meteor/tracker';

import { settings } from '../../../settings';

export const fireGlobalEvent = function _fireGlobalEvent(eventName, params) {
	window.dispatchEvent(new CustomEvent(eventName, { detail: params }));

	Tracker.autorun((computation) => {
		const enabled = settings.get('Iframe_Integration_send_enable');
		if (enabled === undefined) {
			return;
		}
		computation.stop();
		if (enabled) {
			parent.postMessage({
				eventName,
				data: params,
			}, settings.get('Iframe_Integration_send_target_origin'));
		}
	});
};