Channel API Presence not triggering

Question

I'm trying to handle disconnect / connect states using Presence in the Channel API.

Here are some of my code.

app.yaml

handlers:
- url: /(.*\.(gif|png|jpg|ico|js|css))
  static_files: \1
  upload: (.*\.(gif|png|jpg|ico|js|css))

- url: .*
  script: main.py

inbound_services:
- channel_presence

main.py

class onConnect(webapp.RequestHandler):
  def post(self):
    for user in users:
      users = User.all().fetch(1000)
      client = client_id = self.request.get('from')
      channel.send_message(user.channel,' connected');

class onDisconnect(webapp.RequestHandler):
  def post(self):
    Mainpage()
    for user in users:
      users = User.all().fetch(1000)
      client = client_id = self.request.get('from')
      channel.send_message(user.channel, ' disconnected');

application = webapp.WSGIApplication(
                                     [('/', MainPage),
                                     ('/_ah/channel/connected/',onConnect),
                                     ('/_ah/channel/disconnected/',onDisconnect),
                                     ('/chat',handleChat)],
                                     debug=True)

Javascript

<script>
        openChannel = function(){
            var token = '{{ token }}';
            var channel = new goog.appengine.Channel(token);
            var handler = {
                  'onopen': onOpened,
                  'onmessage': onMessage,
                  'onerror': function() {},
                  'onclose': function() {}
                };
            var socket = channel.open(handler);
            socket.onopen = onOpened;
            socket.onmessage = onMessage;

            var chat = document.getElementById('chatinput');
                chat.onkeyup = function(e){
                    if(e.keyCode == 13){
                        sendChat(this.value);
                        this.value = '';
                    }
                }
        }

        sendMessage = function(path, opt_param) {
            if (opt_param) {
                path += '?' + opt_param;
            }
            var xhr = new XMLHttpRequest();
            xhr.open('POST', path, true);
            xhr.send();
        };

        onOpened = function(){
            console.log('Channel Opened');  
            var chatlog = document.getElementById('chatlog');
            var msg = document.createElement('div');
                msg.innerHTML = 'Channel Opened';
                chatlog.appendChild(msg);
            sendMessage('/chat','m='+'A User Joined.');
        }

        onMessage = function(m){
            console.log('Message Recieved');
            var chatlog = document.getElementById('chatlog');
            var msg = document.createElement('div');
            var d = new Date();
                msg.innerHTML = d.toLocaleTimeString() + ': ' + m.data;
                chatlog.appendChild(msg);
        }

        sendChat = function(msg){
            console.log(msg);
            sendMessage('/chat','m='+msg);
        }

        openChannel();
    </script>

Using this code, connnect and disconnect is not triggering when a user closes their browser or whatever.

Are there anything wrong with this code?

Do you actually create a token and initialize client side? I don't see the code of that part in your question. — alex
What do you see in your logs for /_ah/channel/connected and /_ah/channel/disconnected? — Nick Johnson
are you on SDK 1.6.5? Do you notice the problem when they just reload the page? — Anentropic

Alex Dvoretsky Alex Dvoretsky · Accepted Answer · 2015-08-27T11:46:06

Yes, route list is wrong. Put ('/', MainPage) in the end of the routes list. From webapp2 URI routing guide:

When the application receives a request, it tries to match each one in order until one matches, and then call the corresponding handler.

Channel API Presence not triggering

1 Answers