jQuery-xPubSub

A very minimal client-side publish/subscribe system on top of jQuery.

Publish/subscribe allows greater degree of separation between components when designing large or complex javascript application. See the test-mvc.html file for an example.

Under the hood, it is just a sugar coating on top of $.bind and $.trigger with an additional $.connect that helps reduce a lot of glue code for you. But in reality, publish/subscribe is an entirely different mode of thought.

In large events-based system, large portion of your code will be glue code gathering data from one component and feeding it into another anyway, so why not make that "gathering data" and "feeding" a first-class thing and model your component accordingly?

If you're drowing in javascript glue code, connecting one interface to another looking up multiple files at a time just to debug one small bug, then xPubSub might help you. Especially so if you prefer functional-style js. :)

• channel - Can be any valid JS object that works with the $(obj).bind function. This is best used (not required) in conjunction with the $.newChannel method below.
• data - Can be anything that isn't null or undefined.

This plugin provides the following methods:

• $.publish(channel, data)

  Publish data to channel channel if data is not null or undefined.

• $.subscribe(channel, handler)

  Subscribe to channel channel using handler handler.

  Handler should have signature: function (data) { } with data being the data object passed exactly as published.

• $.connect(fromChannel, toChannel, translator)

  Connect two channels together, so when data arrives on fromChannel, it is automatically published to toChannel as well.

  Optionally, a translator function with signature: function(data) { return translatedData; } maybe provided. The data parameter being published to the fromChannel. It should returns a translated version of data to be published to toChannel.

  The translator function may also be used as a kind of filter, by selectively returning null. Returning null from the translator function will prevents the message from being published to toChannel

• $.newChannel(channelName)

  Convenience method for creating new channel endpoints. This is not required. Channel endpoint can be any valid javascript object such as a simple {} which the pub/sub system can bind (using $.bind) events to.