aswi2021vochomurka-gitlab/aswi2021vochomurka/service/mqtt/mqtt_subscriber.py @ f3873472

import paho.mqtt.client as mqtt

from aswi2021vochomurka.service.message_parser import parse_mqtt_message, ParseException
from aswi2021vochomurka.service.subscriber import Subscriber


class MQTTSubscriber(Subscriber):

    # The callback for when the client receives a CONNACK response from the server.
    def on_connect(self, client, userdata, flags, rc, properties=None):
        print("Connected with result code " + str(rc))
        self.callback.onConnected()

        # Subscribing in on_connect() means that if we lose the connection and
        # reconnect then subscriptions will be renewed.
        for topic in self.params.topics:
            print("Subscribed to topic: " + topic)
            client.subscribe(topic)

    # The callback for when a PUBLISH message is received from the server.
    def on_message(self, client, userdata, message: mqtt.MQTTMessage):
        try:
            m = parse_mqtt_message(message)
            print(m)
            self.callback.onMessage(m)
            self.write_to_file(m)
        except ParseException as error:
            print('invalid message data format')
            # TODO better reaction on bad format
            pass

    def on_disconnect(self, client, userdata, rc):
        self.callback.onDisconnected()
        self.stop()

    def start(self):
        super().start()
        client = mqtt.Client()
        client.on_connect = self.on_connect
        client.on_message = self.on_message
        client.on_disconnect = self.on_disconnect

        if not self.params.anonymous:
            client.tls_set()
            client.username_pw_set(self.params.username, self.params.password)

        try:
            client.connect(
                self.params.connection.host,
                self.params.connection.port,
                self.params.connection.timeout
            )
        except Exception as error:
            self.callback.onError()
            return

        client.loop_forever()