Mqtt

This is an mqtt client written in Dart. It can be used in the browser (over websocket) or the VM (over socker or websocket).

See http://mqtt.org/ for details on mqtt protocol.

Usage

Create a connection over websocket:

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

Create a connection over socket:

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

Create mqtt client:

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

Set a will (must be done before connecting to the broker):

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

Connect to broker:

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

Publish a message:

c.publish("MyTopic", "MyMessage", 1, QOS_1, 0)
    .then( (m) => print("Message ${m.messageID} published"); );

Subscribe to a topic:

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

Unsubscribe:

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

Disconnect:

c.disconnect();    

VM Example

See example/mqtt_sub/ for a sample mqtt publish and example/mqtt_pub/ for a sample subscribe. Available options can be displayed through:

• dart mqtt_sub.dart -h
• dart mqtt_pub.dart -h

Web Example

See example/mqtt_web for a sample web page connecting, subscribing and publishing mqtt messages

Testing

Testing was done using the mosquitto broker (http://mosquitto.org/). A mosquitto test server is available at http://test.mosquitto.org/.

Websocket testing was done through mqtt_ws_bridge.dart.