mqtt-connection   

Barebone Connection object for MQTT. Works over any kind of binary Streams, TCP, TLS, WebSocket, ...

It uses mqtt-packet for generating and parsing MQTT packets. See it for the full documentations on the packet types.

This library works with node v0.10 and node v0.8, but it requires at least NPM 1.4. To upgrade on node v0.8, run npm install npm@v1.4-latest -g.

Acknowledgements

This library has been extracted and refactored from MQTT.js. Thanks Adam Rudd for the great module.

Install

npm install mqtt-connection --save

Usage

As a client:

var net     = require('net')
  , mqttCon = require('mqtt-connection')
  , stream  = net.createConnection(1883, 'localhost')
  , conn    = mqttCon(stream);

// conn is your MQTT connection!

As a server:

var net     = require('net')
  , mqttCon = require('mqtt-connection')
  , server  = new net.Server();

server.on('connection', function(stream) {
  var conn = mqttCon(stream);

  // conn is your MQTT connection!
});

As a websocket server:

var websocket = require('websocket-stream')
  , WebSocketServer = require('ws').Server
  , Connection = require('mqtt-connection')
  , server = http.createServer()

function attachWebsocketServer(server, handler) {
  var wss = new WebSocketServer({server: server})

  if (handler)
    server.on('client', handler)

  wss.on('connection', function(ws) {
    var stream = websocket(ws)
    var connection = new Connection(stream)

    server.emit("client", connection)
  })

  return server
}

attachWebsocketServer(server)

API

Creates a new MQTT Connection.

Options:

• encoding: encoding of the payload. See buffer docs
• notData: do not listen to the 'data' event, so that it can respect backpressure. Pipe the Connection to another stream to consume the packets. If this option is passed true the object will emit no packet-related events.

Connection#connect(options, [callback])

Send an MQTT connect packet.

options supports the following properties:

• protocolId: Protocol ID, usually MQIsdp. string
• protocolVersion: Protocol version, usually 3. number
• keepalive: keepalive period in seconds. number
• clientId: client ID. string
• will: the client's will message options. object that supports the following properties:
  • topic: the will topic. string
  • payload: the will payload. string
  • qos: will qos level. number
  • retain: will retain flag. boolean
• clean: the 'clean start' flag. boolean
• username: username for protocol v3.1. string
• password: password for protocol v3.1. string

Connection#connack(options, [callback])

Send an MQTT connack packet.

options supports the following properties:

• returnCode: the return code of the connack, success is indicated by 0. number

Connection#publish(options, [callback])

Send an MQTT publish packet.

options supports the following properties:

• topic: the topic to publish to. string
• payload: the payload to publish, defaults to an empty buffer. string or buffer
• qos: the quality of service level to publish on. number
• messageId: the message ID of the packet, required if qos > 0. number
• retain: retain flag. boolean

Connection#puback #pubrec #pubcomp #unsuback(options, [callback])

Send an MQTT [puback, pubrec, pubcomp, unsuback] packet.

options supports the following properties:

• messageId: the ID of the packet

Connection#pubrel(options, [callback])

Send an MQTT pubrel packet.

options supports the following properties:

• dup: duplicate message flag
• messageId: the ID of the packet

Connection#subscribe(options, [callback])

Send an MQTT subscribe packet.

options supports the following properties:

• dup: duplicate message flag
• messageId: the ID of the packet
• subscriptions: a list of subscriptions of the form [{topic: a, qos: 0}, {topic: b, qos: 1}]

Connection#suback(options, [callback])

Send an MQTT suback packet.

options supports the following properties:

• granted: a vector of granted QoS levels, of the form [0, 1, 2]
• messageId: the ID of the packet

Connection#unsubscribe(options, [callback])

Send an MQTT unsubscribe packet.

options supports the following properties:

• messageId: the ID of the packet
• dup: duplicate message flag
• unsubscriptions: a list of topics to unsubscribe from, of the form ["topic1", "topic2"]

Connection#pingreq #pingresp #disconnect(options, [callback])

Send an MQTT [pingreq, pingresp, disconnect] packet.

Event: 'connect'

function(packet) {}

Emitted when an MQTT connect packet is received by the client.

packet is an object that may have the following properties:

• version: the protocol version string
• versionNum: the protocol version number
• keepalive: the client's keepalive period
• clientId: the client's ID
• will: an object with the following keys:
  • topic: the client's will topic
  • payload: the will message
  • retain: will retain flag
  • qos: will qos level
• clean: clean start flag
• username: v3.1 username
• password: v3.1 password

Event: 'connack'

function(packet) {}

Emitted when an MQTT connack packet is received by the client.

packet is an object that may have the following properties:

• returnCode: the return code of the connack packet

Event: 'publish'

function(packet) {}

Emitted when an MQTT publish packet is received by the client.

packet is an object that may have the following properties:

• topic: the topic the message is published on
• payload: the payload of the message
• messageId: the ID of the packet
• qos: the QoS level to publish at

Events: <'puback', 'pubrec', 'pubrel', 'pubcomp', 'unsuback'>

function(packet) {}

Emitted when an MQTT [puback, pubrec, pubrel, pubcomp, unsuback] packet is received by the client.

packet is an object that may contain the property:

• messageId: the ID of the packet

Event: 'subscribe'

function(packet) {}

Emitted when an MQTT subscribe packet is received.

packet is an object that may contain the properties:

• messageId: the ID of the packet
• subscriptions: an array of objects representing the subscribed topics, containing the following keys
  • topic: the topic subscribed to
  • qos: the qos level of the subscription

Event: 'suback'

function(packet) {}

Emitted when an MQTT suback packet is received.

packet is an object that may contain the properties:

• messageId: the ID of the packet
• granted: a vector of granted QoS levels

Event: 'unsubscribe'

function(packet) {}

Emitted when an MQTT unsubscribe packet is received.

packet is an object that may contain the properties:

• messageId: the ID of the packet
• unsubscriptions: a list of topics the client is unsubscribing from, of the form [topic1, topic2, ...]

Events: <'pingreq', 'pingresp', 'disconnect'>

function(packet){}

Emitted when an MQTT [pingreq, pingresp, disconnect] packet is received.

packet only includes static header information and can be ignored.

License

MIT