mqtt_over_websockets

mows

MQTT Over Websockets Client Library

based on

http://git.eclipse.org/c/paho/org.eclipse.paho.mqtt.javascript.git/plain/src/mqttws31.js

Send and receive messages using web browsers.

This programming interface lets a Node client application use the MQTT V3.1 protocol to connect to an MQTT-supporting messaging server.

The function supported includes:

1. Connecting to and disconnecting from a server. The server is identified by its host name and port number.
2. Specifying options that relate to the communications link with the server, for example the frequency of keep-alive heartbeats, and whether SSL/TLS is required.
3. Subscribing to and receiving messages from MQTT Topics.
4. Publishing messages to MQTT Topics.

The API consists of two main objects:

The Messaging.Client object. This contains methods that provide the functionality of the API, including provision of callbacks that notify the application when a message arrives from or is delivered to the messaging server, or when the status of its connection to the messaging server changes.

The Messaging.Message object. This encapsulates the payload of the message along with various attributes associated with its delivery, in particular the destination to which it has been (or is about to be) sent.

The programming interface validates parameters passed to it, and will throw an Error containing an error message intended for developer use, if it detects an error with any parameter.

Installation:
npm install mqtt_over_websockets

Includes:
var Messaging = require("mqtt_over_websockets");

Sample Working Complete Source Code

var Messaging = require("mqtt_over_websockets");

var wsClient = null;

function defaultClientId(){
	return "WS" + (Math.random() + 1).toString(36).substring(10);
	//return "WScoj8xgvi";
}

// the client is notified when it is connected to the server.
var onConnect = function(frame) {
	console.log("WS:Connected:Successfully");
	wsClient.subscribe('/Ashutosh');
	var message = new Messaging.Message("JAI GANESH JI MAHARAJ KI JAI");
	message.destinationName = "/Ashutosh";
  	wsClient.send(message);
};


function onFailure(failure) {
	console.log("WS:Failure:" + failure.errorMessage);
}

function onMessageArrived(message) {
	console.log("WS:Message Arrived: Topic:" + message.destinationName + ":Msg:" + message.payloadString);
}

function onConnectionLost(responseObject) {
	if (responseObject.errorCode !== 0) {
		console.log("WS:Connection Lost:"  + wsClient.clientId + ": " + responseObject.errorCode + "\n");
	}
}

var PLATFORM_IP 			= 'SERVER-IP';
var PLATFORM_PORT 			= SERVER-PORT;
var CLIENT_ID 				= defaultClientId();
var USER 				= 'USER-ID';
var PASSWD 				= 'PASSWORD';


function doConnection(ip,port,clientId,username,passwd){
	console.log("Default Client-Id:" + clientId);
	wsClient = new Messaging.Client(ip, port , clientId);
	wsClient.onConnect = onConnect;
	wsClient.onMessageArrived = onMessageArrived;
	wsClient.onConnectionLost = onConnectionLost;
	wsClient.connect({userName: username, password:passwd, onSuccess:onConnect, onFailure:onFailure});
}

doConnection(PLATFORM_IP,PLATFORM_PORT,CLIENT_ID,USER,PASSWD);