Belfry.js

A simple publish subscribe library returning curried functions to work with cumin.

Installation

Belfry relies on cumin.js, as currently I use cumin for all my functional requirements.

1. install cumin.js and belfry.js, The easiest way to do this is using bower bower install cumin belfry.
2. Include using script tags.

<script type="text/javascript" src="path/to/cumin.js"></script>
<script type="text/javascript" src="path/to/belfry.js"></script>

Usage

Belfry provides a singlton instance from the method getTower.

var tower = Belfry.getTower();

Instance methods are publish, subscribe and unsubscribe.

// create a function to subscribe to topics
var logger = function( data, topic ){
    console.log( topic, data );
};

// subscribe to topic 'channel1'
// Keep returned id to unsubscribe
var subscriberId = tower.subscribe('channel1')(logger);

// publish to 'channel1'
// returns true if any listerns otherwise returns false
tower.publish('channel1')({message: 'Hello, World!'});

// Unsubscribe from topic
// requires both channel and subscriberId
tower.unsubscribe('channel1')(subscriberId);

Tips

Use curried function to create custom listeners

var ListenToResizeEvents = tower.subscribe('resize-events');

// Later
ListenToResizeEvents(logger);

Unsubscribe all listeners from a topic by not passing a subscriberId

ListenToResizeEvents(logger);
ListenToResizeEvents(otherFunc);

var clearResizeListeners = tower.unsubscribe('resize-events');
clearResizeListeners();

Debug Code

Useful code snippet to listen to all messages passing through a channel using cumin.

var logChannel = _.compose(_.invoke(_.log), tower.subscribe);

logChannel('thisChannel');

_.each(logChannel)('listen', 'to', 'all', 'these', 'channels');