JSPM

  • ESM via JSPM
  • ES Module Entrypoint
  • Export Map
  • Keywords
  • License
  • Repository URL
  • TypeScript Types
  • README
  • Created
  • Published
  • Downloads 1264054
  • Score
    100M100P100Q192136F
  • License MIT

Parse and generate MQTT packets like a breeze

Package Exports

  • mqtt-packet

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (mqtt-packet) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

mqtt-packet   Build Status

Encode and Decode MQTT packets the node way.

Acknowledgements

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

Installation

npm install mqtt-packet --save

Examples

Generating

var mqtt    = require('mqtt-packet')
  , object  = {
        cmd: 'publish'
      , retain: false
      , qos: 0
      , dup: false
      , length: 10
      , topic: 'test'
      , payload: 'test'
    }

console.log(mqtt.generate(object))
// prints
// <Buffer 30 0a 00 04 74 65 73 74 74 65 73 74>
//
// the same as
//
// new Buffer([
//   48, 10, // Header
//   0, 4, // Topic length
//   116, 101, 115, 116, // Topic (test)
//   116, 101, 115, 116 // Payload (test)
// ])

Parsing

var mqtt      = require('mqtt-packet')
  , parser    = mqtt.parser()

// synchronously emits all the parsed packets
parser.on('packet', function(packet) {
  console.log(packet)
  // prints:
  //
  // {
  //     cmd: 'publish'
  //   , retain: false
  //   , qos: 0
  //   , dup: false
  //   , length: 10
  //   , topic: 'test'
  //   , payload: 'test'
  // }
})

parser.parse(new Buffer([
  48, 10, // Header
  0, 4, // Topic length
  116, 101, 115, 116, // Topic (test)
  116, 101, 115, 116 // Payload (test)
])
// returns the number of bytes left in the parser

Streams

var mqtt      = require('mqtt-packet')
  , assert    = require('assert')
  , parser    = mqtt.parseStream()
  , generator = mqtt.generateStream()
  , object  = {
        cmd: 'publish'
      , retain: false
      , qos: 0
      , dup: false
      , length: 10
      , topic: 'test'
      , payload: 'test'
    }

generator.pipe(parser)

parser.on('data', function(packet) {
  assert.deepEqual(packet, object, 'expected packet')
})

generator.end(object)

Duplex Wrapper

var mqtt        = require('mqtt-packet')
  , assert      = require('assert')
  , through     = require('through2')
  , connection  = mqtt.connection(through())
  , object      = {
        cmd: 'publish'
      , retain: false
      , qos: 0
      , dup: false
      , length: 10
      , topic: 'test'
      , payload: 'test'
    }

connection.on('data', function(packet) {
  assert.deepEqual(packet, object, 'expected packet')
})

connection.end(object)

API

### mqtt.generate(object)

Generates a Buffer containing an MQTT packet. The object must be one of the ones specified by the packets section. Throws an Error if a packet cannot be generated.

### mqtt.parser(opts)

Returns a new Parser object. Parser inherits from EventEmitter and will emit:

The only allowed option is { encoding: 'binary' } which will block the automatic parsing of all the strings in the package. Instead, the strings will remain 'raw', i.e. a Buffer.

#### Parser.parse(buffer)

Parse a given Buffer and emits synchronously all the MQTT packets that are included. Returns the number of bytes left to parse.

 ### mqtt.generateStream()

Returns a Transform stream that calls generate(). The stream is configured into object mode.

### mqtt.parseStream(opts)

Returns a Transform stream that embeds a Parser and calls Parser.parse() for each new Buffer. The stream is configured into object mode. It accepts the same options of parser(opts).

### mqtt.connection(duplex, opts)

Wraps a duplex using reduplexer so that the user can both write and read an object, as defined in packets. It accepts the same options of parser(opts).

Packets

This section describes the format of all packets emitted by the Parser and that you can input to generate.

Connect

{
    cmd: 'connect'
  , protocolId: 'MQTT' // or 'MQIsdp' in MQTT 3.1.1
  , protocolVersion: 4 // or 3 in MQTT 3.1
  , clean: true // or false
  , clientId: 'my-device'
  , keepalive: 0 // seconds, 0 is the default, can be any positive number
  , username: 'matteo'
  , password: 'collina'
  , will: {
        topic: 'mydevice/status'
      , payload: 'dead'
    }
}

The only mandatory argument is clientId, as generate will throw if missing.

Connack

{
    cmd: 'connack'
  , returnCode: 0 // or whatever else you see fit
}

The only mandatory argument is returnCode, as generate will throw if missing.

Subscribe

{
    cmd: 'subscribe'
  , messageId: 42
  , subscriptions: [{
        topic: 'test'
      , qos: 0
    }]
}

All properties are mandatory.

Suback

{
    cmd: 'suback'
  , messageId: 42
  , granted: [0, 1, 2, 128]
}

All the granted qos must be < 256, as they are encoded as UInt8. All properties are mandatory.

Unsubscribe

{
    cmd: 'unsubscribe'
  , messageId: 42
  , unsubscriptions: [
        'test'
      , 'a/topic'
    ]
}

All properties are mandatory.

Unsuback

{
    cmd: 'unsuback'
  , messageId: 42
}

All properties are mandatory.

Publish

{
    cmd: 'publish'
  , messageId: 42
  , qos: 2
  , dup: false
  , topic: 'test'
  , payload: 'test'
  , retain: false
}

Only the topic and properties are mandatory Both topic and payload can be Buffer objects instead of strings. messageId is mandatory for qos > 0.

Puback

{
    cmd: 'puback'
  , messageId: 42
}

The only mandatory argument is messageId, as generate will throw if missing.

Pubrec

{
    cmd: 'pubcomp'
  , messageId: 42
}

The only mandatory argument is messageId, as generate will throw if missing.

Pubrel

{
    cmd: 'pubrel'
  , messageId: 42
}

The only mandatory argument is messageId, as generate will throw if missing.

Pubcomp

{
    cmd: 'pubcomp'
  , messageId: 42
}

The only mandatory argument is messageId, as generate will throw if missing.

Pingreq

{
  cmd: 'pingreq'
}

Pingresp

{
  cmd: 'pingresp'
}

Disconnect

{
  cmd: 'pingresp'
}

License

MIT