Simple pywebsocket setup for listening to MQTT broker.

glass_wsh.py

_OPEN_ = 1
_CLOSING_ = 2
_CLOSE_ = 3
_status_ = _CONNECTING_

# broker information for mqtt
_BROKER_URL = "localhost"
_BROKER_PORT = 1883
_TOPIC_BASE = "justin/glass"

class broker():

    def __init__(self, url, port, topic, socket):
        self.url = url
        self.port = port
        self.socket = socket
        self.topic = topic
        self.clientid = ''.join(random.choice(string.ascii_letters + string.digits) for letter in xrange(23))
        self.client = mosquitto.Mosquitto(self.clientid)

        self.client.on_message = self.onMessage
        self.client.on_connect = self.onConnect
        self.client.on_subscribe = self.onSubscribe
        self.client.on_publish = self.onPublish

        self.client.connect(self.url)
        self.client.subscribe(_TOPIC_BASE + "/#", 2)

    def close(self):
        self.client.disconnect()

    def onMessage(self, mosq, obj, msg):
        if _status_ == _OPEN_:
                try:
                        string = json.dumps({"topic": msg.topic, "message": msg.payload})
                        self.socket.ws_stream.send_message(string)
                except Exception:
                        #self.socket.ws_stream.send_message("There was a message but I don't know what happened")
                        return

    def onConnect(self, mosq, obj, rc):
        if rc == 0:
            string = json.dumps({"topic": self.topic + "/status", "message": "Connected to Justin's Glass"})
            self.socket.ws_stream.send_message(string)

    def onSubscribe(self, mosq, obj, mid, granted_qos):
        if _status_ == _OPEN_:
            string = json.dumps({"topic": self.topic + "/status", "message": "Subscribed to timer"})
            self.socket.ws_stream.send_message(string)

    def onPublish(self, mosq, obj, mid):
        if _status_ == _OPEN_:
            try:
                string = json.dumps({"topic": self.topic + "/status", "message": "Message published to broker"})
                self.socket.ws_stream.send_message(string)
            except Exception:
                return

    def run(self):
        global _status_

        #keep web socket connected while mqtt is connected
        while self.client.loop() == 0:
            #self.socket.ws_stream.send_message(str(_status_))
            if _status_ == _OPEN_:
                #self.socket.ws_stream.send_message("open")
                pass
            else:
                #self.socket.ws_stream.send_message("disconnecting")
                self.client.disconnect()
                break

def web_socket_do_extra_handshake(request):
    pass  # Always accept.

def web_socket_transfer_data(request):
    global _status_
    _status_ = _OPEN_

    instance = broker(_BROKER_URL, _BROKER_PORT, _TOPIC_BASE, request)

    arr = ()
    talk = thread.start_new_thread(instance.run, arr)
    while True:
        try:
            #######################################################
            # Note::
            # mesgutil.receive_message() returns 'unicode', so
            # if you want to treated as 'string', use encode('utf-8')
            #######################################################
            line = request.ws_stream.receive_message()

            # client is still alive
            if line == _HEARTBEAT:
                continue

        except Exception:
            _status_ = _CLOSING_
            # wait until _status_ change.
            i = 0
            while _status_ == _CLOSING_:
                time.sleep(0.5)
                i += 1
                if i > 10:
                    break
            instance.close()
            # close connection
            return