Rocket.Chat/app/ui-master/server/scripts.ts

import { debounce } from 'underscore';

import { settings } from '../../settings/server';
import { addScript } from './inject';

const getContent = (): string => `
${ process.env.DISABLE_ANIMATION ? 'window.DISABLE_ANIMATION = true;\n' : '' }

${ settings.get('API_Use_REST_For_DDP_Calls') ? 'window.USE_REST_FOR_DDP_CALLS = true;\n' : '' }
${ settings.get('ECDH_Enabled') ? 'window.ECDH_Enabled = true;\n' : '' }
// Custom_Script_Logged_Out
window.addEventListener('Custom_Script_Logged_Out', function() {
	${ settings.get('Custom_Script_Logged_Out') }
})


// Custom_Script_Logged_In
window.addEventListener('Custom_Script_Logged_In', function() {
	${ settings.get('Custom_Script_Logged_In') }
})


// Custom_Script_On_Logout
window.addEventListener('Custom_Script_On_Logout', function() {
	${ settings.get('Custom_Script_On_Logout') }
})

${ settings.get('Accounts_ForgetUserSessionOnWindowClose') ? `
window.addEventListener('load', function() {
	if (window.localStorage) {
		Object.keys(window.localStorage).forEach(function(key) {
			window.sessionStorage.setItem(key, window.localStorage.getItem(key));
		});
		window.localStorage.clear();
		Meteor._localStorage = window.sessionStorage;
	}
});
` : '' }`;

settings.get(/(API_Use_REST_For_DDP_Calls|Custom_Script_Logged_Out|Custom_Script_Logged_In|Custom_Script_On_Logout|Accounts_ForgetUserSessionOnWindowClose|ECDH_Enabled)/, debounce(() => {
	const content = getContent();
	addScript('scripts', content);
}, 1000));