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

import { Meteor } from 'meteor/meteor';
import { Tracker } from 'meteor/tracker';
import { Blaze } from 'meteor/blaze';
import { Template } from 'meteor/templating';
import { FlowRouter } from 'meteor/kadira:flow-router';
import { BlazeLayout } from 'meteor/kadira:blaze-layout';
import { Session } from 'meteor/session';
import mem from 'mem';
import _ from 'underscore';

import { ChatSubscription, Rooms } from '../../../models';
import { settings } from '../../../settings';
import { callbacks } from '../../../callbacks';
import { roomTypes, handleError } from '../../../utils';

import { RoomManager, fireGlobalEvent, RoomHistoryManager } from '..';

window.currentTracker = undefined;

const getDomOfLoading = mem(function getDomOfLoading() {
	const loadingDom = document.createElement('div');
	const contentAsFunc = (content) => () => content;

	const template = Blaze._TemplateWith({ }, contentAsFunc(Template.loading));
	Blaze.render(template, loadingDom);

	return loadingDom;
});

function replaceCenterDomBy(dom) {
	const mainNode = document.querySelector('.main-content');
	if (mainNode) {
		for (const child of Array.from(mainNode.children)) {
			if (child) { mainNode.removeChild(child); }
		}
		mainNode.appendChild(dom);
	}

	return mainNode;
}

export const openRoom = function(type, name) {
	window.currentTracker = Tracker.autorun(function(c) {
		const user = Meteor.user();
		if ((user && user.username == null) || (user == null && settings.get('Accounts_AllowAnonymousRead') === false)) {
			BlazeLayout.render('main');
			return;
		}

		if (RoomManager.open(type + name).ready() !== true) {
			if (settings.get('Accounts_AllowAnonymousRead')) {
				BlazeLayout.render('main');
			}
			replaceCenterDomBy(getDomOfLoading());
			return;
		}
		if (window.currentTracker) {
			window.currentTracker = undefined;
		}
		c.stop();

		const room = roomTypes.findRoom(type, name, user);
		if (room == null) {
			if (type === 'd') {
				Meteor.call('createDirectMessage', name, function(error) {
					if (!error) {
						RoomManager.close(type + name);
						return openRoom('d', name);
					}
					Session.set('roomNotFound', { type, name, error });
					BlazeLayout.render('main', { center: 'roomNotFound' });
				});
			} else {
				Meteor.call('getRoomByTypeAndName', type, name, function(error, record) {
					if (error) {
						Session.set('roomNotFound', { type, name, error });
						return BlazeLayout.render('main', { center: 'roomNotFound' });
					}
					Rooms.upsert({ _id: record._id }, _.omit(record, '_id'));
					RoomManager.close(type + name);
					return openRoom(type, name);
				});
			}
			return;
		}

		const roomDom = RoomManager.getDomOfRoom(type + name, room._id);
		const mainNode = replaceCenterDomBy(roomDom);

		if (mainNode) {
			if (roomDom.classList.contains('room-container')) {
				roomDom.querySelector('.messages-box > .wrapper').scrollTop = roomDom.oldScrollTop;
			}
		}

		Session.set('openedRoom', room._id);
		RoomManager.openedRoom = room._id;

		fireGlobalEvent('room-opened', _.omit(room, 'usernames'));

		Session.set('editRoomTitle', false);
		// KonchatNotification.removeRoomNotification(params._id)
		// update user's room subscription
		const sub = ChatSubscription.findOne({ rid: room._id });
		if (sub && sub.open === false) {
			Meteor.call('openRoom', room._id, function(err) {
				if (err) {
					return handleError(err);
				}
			});
		}

		if (FlowRouter.getQueryParam('msg')) {
			const msg = { _id: FlowRouter.getQueryParam('msg'), rid: room._id };
			RoomHistoryManager.getSurroundingMessages(msg);
		}

		return callbacks.run('enter-room', sub);
	});
};