pub-sub-js

pub-sub-js is tiny library with zero dependencies that implements distributed publish/subscribe messaging system.

$ npm install pub-sub-js

Why not use zeromq ? Because of this bug.

Usage

Publish messages to channels:

var Pub = require('pub-sub-js').Publisher;

var publisher = new Pub();

publisher.listen(8002);

setInterval(function () {

  publisher.publish('channel_one', 'message_one');
  publisher.publish('channel_two', {message: 'two'});
  publisher.publish('channel_three', ['message', 'three']);

}, 1000);

Subscribe to channels and receive the messages:

var Sub = require('pub-sub-js').Subscriber;

var subscriber = new Sub();

subscriber.subscribe('channel_one');
subscriber.connect(8002, '127.0.0.1');
subscriber.subscribe('channel_two');

subscriber.on('message', function (channel, data) {

  console.log(channel, data);
});

Output:

channel_one message_one
channel_two { message: 'two' }

Message three will not be received because there is no subscription to the channel_three. There will be no network traffic on publisher.send('channel_three', ...) call.

API

###Class: Subscriber

.subscribe(channel)

Subscribes to the channel.

.unsubscribe(channel)

Unsubscribes from the channel.

.connect(port, [host])

Opens connection to the Publisher. See net.Socket.connect().

.disconnect(port, [host])

Closes the connection.

.listen(port, [host])

Begin accepting connections on the specified port and hostname. See net.Server.listen().

.close([callback])

Stops from accepting new connections. See net.Server.close().

Event: 'message' (channel, data)

Emitted when the message is received.

Event: 'log' (args)

Can be used for debugging.

###Class: Publisher

.publish(channel, message)

Publish message to the channel.