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/assets/javascripts/channels/meeting_updates.js

@@ -21,7 +21,7 @@
       $(".center-panel-wrapper").html(html);
       displayRoomURL();
     });
-  }
+  };
 
   var initRooms = function() {
     App.messages = App.cable.subscriptions.create({
@@ -43,6 +43,13 @@
         } else if (data.action === 'meeting_ended') {
           sessionStatusRefresh($('.meeting-url').val());
           showAlert(I18n.meeting_ended, 4000);
+        } else if (data.action === 'user_waiting') {
+          // show a browser notification only to the owner
+          if (GreenLight.user.roomOwner) {
+            showNotification(I18n.user_waiting_title, {
+              body: I18n.user_waiting_body.replace(/%{user}/, data.user)
+            });
+          }
         }
       }
     });

app/assets/javascripts/shared.js.erb

@@ -32,7 +32,7 @@ var loopJoin = function() {
   jqxhr.fail(function(xhr, status, error) {
     console.info("meeting join failed");
   });
-}
+};
 
 var alertTimeout = null;
 var showAlert = function(html, timeout_delay) {
@@ -54,3 +54,19 @@ var showAlert = function(html, timeout_delay) {
 var displayRoomURL = function() {
   $('.meeting-url').val(Meeting.getInstance().getURL());
 };
+
+var showNotification = function(title, options) {
+  if (Notification.permission === "granted") {
+    var icon = '<%= asset_path("bbb-logo.png") %>';
+    options = $.extend(options, {
+      icon: icon
+    });
+    var notification = new Notification(title, options);
+    notification.onclick = function() {
+      window.focus();
+    };
+  }
+};
+
+// TODO: only need permissions if the user is signed in
+Notification.requestPermission();

app/controllers/bbb_controller.rb

@@ -52,8 +52,13 @@ class BbbController < ApplicationController
         options
       )
 
+      # the user can join the meeting
       if bbb_res[:returncode] && current_user && current_user == user
         JoinMeetingJob.perform_later(user.encrypted_id)
+
+      # user will be waiting for a moderator
+      else
+        NotifyUserWaitingJob.perform_later(user.encrypted_id, params[:name])
       end
 
       render_bbb_response bbb_res, bbb_res[:response]

app/helpers/users_helper.rb

@@ -15,4 +15,8 @@
 # with BigBlueButton; if not, see <http://www.gnu.org/licenses/>.
 
 module UsersHelper
+  def is_room_owner
+    token = current_user ? current_user.encrypted_id : nil
+    token.present? && params[:id].present? && token == params[:id]
+  end
 end

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

app/views/layouts/application.html.erb

@@ -77,10 +77,13 @@ with BigBlueButton; if not, see <http://www.gnu.org/licenses/>.
   </body>
 </html>
 
+<!-- Global javascript variables and helpers -->
 <script type="text/javascript">
   window.I18n = <%= client_translations.to_json.html_safe %>
   window.GreenLight = {};
   window.GreenLight.META_LISTED = "<%= BbbApi::META_LISTED %>";
   window.GreenLight.META_TOKEN = "<%= BbbApi::META_TOKEN %>";
   window.GreenLight.META_HOOK_URL = "<%= BbbApi::META_HOOK_URL %>";
+  window.GreenLight.user = {};
+  window.GreenLight.user.roomOwner = <%= is_room_owner %>;
 </script>

config/locales/en-us.yml

@@ -54,6 +54,8 @@ en-US:
     recording_unlisted: Recording was unlisted
     recording_unpublished: Recording was unpublished
     unpublish_recording: Hide recording
+    user_waiting_body: "%{user} is waiting to join your room!"
+    user_waiting_title: A user is waiting
   copied: Copied
   copy_error: Use Ctrl-c to copy
   create_session: Create a Session