mqtt.js is a library for the MQTT protocol, written in JavaScript to be used in node.js.
-
v0.3.0 improves connection stability, performance, the reconnection logic and SSL support. See #118 for details. A Connection is a Writable stream, so you can run MQTT.js over any kind of Stream (doc needed). Both the constructors of MqttClient and MqttConnection changed, but not the factory method
mqtt.createClientandmqtt.createConnection. -
v0.2.0 has brough some API breaking changes to mqtt.js. Please consult the migration guide for information or open an issue if you need any help.
npm install mqtt
First you will need to install and run a broker, such as Mosquitto or Mosca, and launch it.
For the sake of simplicity, let's put the subscriber and the publisher in the same file:
var mqtt = require('mqtt')
client = mqtt.createClient(1883, 'localhost');
client.subscribe('presence');
client.publish('presence', 'Hello mqtt');
client.on('message', function (topic, message) {
console.log(message);
});
client.end();output:
Hello mqtt
If you do not want to install a separate broker, you can try using the server/orig example. It implements enough of the semantics of the MQTT protocol to run the example.
Detailed documentation can be found in the wiki
See: examples/client
var mqtt = require('mqtt')
, client = mqtt.createClient();
client.publish('messages', 'mqtt');
client.publish('messages', 'is pretty cool');
client.publish('messages', 'remember that!', {retain: true});
client.end();var mqtt = require('mqtt')
, client = mqtt.createClient();
client.subscribe('messages');
client.publish('messages', 'hello me!');
client.on('message', function(topic, message) {
console.log(message);
});
client.options.reconnectPeriod = 0; // disable automatic reconnectvar mqtt = require('mqtt')
, client = mqtt.createClient();
client
.subscribe('messages')
.publish('presence', 'bin hier')
.on('message', function(topic, message) {
console.log(topic);
});Included in examples/broadcast.js:
var mqtt = require('mqtt');
mqtt.createServer(function(client) {
var self = this;
if (!self.clients) self.clients = {};
client.on('connect', function(packet) {
client.connack({returnCode: 0});
client.id = packet.clientId;
self.clients[client.id] = client;
});
client.on('publish', function(packet) {
for (var k in self.clients) {
self.clients[k].publish({topic: packet.topic, payload: packet.payload});
}
});
client.on('subscribe', function(packet) {
var granted = [];
for (var i = 0; i < packet.subscriptions.length; i++) {
granted.push(packet.subscriptions[i].qos);
}
client.suback({granted: granted, messageId: packet.messageId});
});
client.on('pingreq', function(packet) {
client.pingresp();
});
client.on('disconnect', function(packet) {
client.stream.end();
});
client.on('close', function(err) {
delete self.clients[client.id];
});
client.on('error', function(err) {
client.stream.end();
console.log('error!');
});
}).listen(1883);MIT