aoldcat / mqtt.dart

dart mqtt client

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.