Show a browser notification when a user is waiting to join a room

The owner of a room receives a browser notification if he has the page open
and another person tries to join his room.

app/jobs/notify_user_waiting_job.rb

@@ -0,0 +1,24 @@
+# BigBlueButton open source conferencing system - http://www.bigbluebutton.org/.
+#
+# Copyright (c) 2016 BigBlueButton Inc. and by respective authors (see below).
+#
+# This program is free software; you can redistribute it and/or modify it under the
+# terms of the GNU Lesser General Public License as published by the Free Software
+# Foundation; either version 3.0 of the License, or (at your option) any later
+# version.
+#
+# BigBlueButton is distributed in the hope that it will be useful, but WITHOUT ANY
+# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+# PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License along
+# with BigBlueButton; if not, see <http://www.gnu.org/licenses/>.
+
+class NotifyUserWaitingJob < ApplicationJob
+  queue_as :default
+
+  def perform(room, user)
+    ActionCable.server.broadcast "#{room}_meeting_updates_channel",
+                                 { action: 'user_waiting', user: user }
+  end
+end