MQTT.DART - MQTT Client Library

I developed the MQTT Dart library as I was working on the backend of a mobile app in 2013. The backend was developed in Dart but I could not find any MQTT library.

I’ve not been too active on the library recently due to lack of time. But I have plan to review the library with the latest Dart features and include the missing MQTT features before the end of the year.

Overview of MQTT.DART MQTT Client Library

Features Supported by MQTT.DART MQTT Client Library

Advanced Features: Supported by MQTT.DART MQTT Client Library

Usage of MQTT.DART MQTT Client Library

How to Install the MQTT.DART MQTT Client Library?

Add this to your package’s pubspec.yaml file:

dependencies:
mqtt: "^1.1.0"

You can install packages from the command line:

$ pub get

In your dart code add:

import 'package:mqtt/mqtt_shared.dart';

How to Connect an MQTT Broker to MQTT.DART MQTT Client Library

1.Define a connection before connecting to the MQTT broker you must define a connection. Web socket and socket connections are supported:

websocket:

var mqttCnx = new MqttConnectionIOWebSocket.setOptions("ws://127.0.0.1/8080");

socket:

var mqttCnx = new MqttConnectionIOSocket.setOptions(host:127.0.0.1, port: 8083);

2.Create a client

MqttClient c = new MqttClient(mqttCnx, clientID: "MyClientID", qos: QOS_1);

3.Connect

c.connect(onConnectionLost) .then( (c)=> onConnected(c) ) .catchError((e) => print("Error: $e"), test: (e) => e is SocketException)
.catchError((mqttErr) => print("Error: $mqttErr") );

Connect with LWT

1. Define a connection Before connecting to the broker you must define a connection. Web socket and socket connections are supported:

websocket:

var mqttCnx = new MqttConnectionIOWebSocket.setOptions("ws://127.0.0.1/8080");

socket:

var mqttCnx = new MqttConnectionIOSocket.setOptions(host:127.0.0.1, port: 8083);

2. Create a client

MqttClient c = new MqttClient(mqttCnx, clientID: "MyClientID", qos: QOS_1);

3. Define the will

c.setWill("MyWillTopic", "MyWillPayload", QOS_1, 0);

4. Connect

c.connect(onConnectionLost) .then( (c)=> onConnected(c) ) .catchError((e) => print("Error: $e"), test: (e) => e is SocketException)
.catchError((mqttErr) => print("Error: $mqttErr") ); 

Connect with Username/ Password

Create the client as:

MqttClient c = new MqttClient(mqttCnx, clientID: "MyClientID", qos: QOS_1, userName: “MyUserName”, password: ”MyPassword”);

Publish

c.publish("MyTopic", "MyMessage")
.then( (m) => print("Message ${m.messageID} published"); 

Publish a retained message

c.publish("MyTopic", "MyMessage", retain: true)
.then( (m) => print("Message ${m.messageID} published"); );

Subscribe

c.subscribe("MyTopic", QOS_1, onMessage) 
.then( (s) => print("Subscription done - ID: ${s.messageID}

Unsubscribe

c.unsubscribe("MyTopic", s.messageID) 
.then( (u) => print("Unsubscribed from subscription ${u.messageID}") );

Disconnect

c.disconnect();