Marionette.EventAggregator
==========================

An event aggregator is an application level pub/sub mechanism that
allows various pieces of an otherwise segmented and disconnected system
to communicate with each other.

Marionette's EventAggregator is facilitated by
`Backbone.Wreqr <https://github.com/marionettejs/backbone.wreqr>`_'s
EventAggregator object and
`Backbone.EventBinder <https://github.com/marionettejs/backbone.eventbinder>`_.
It combines an EventBinder in to the EventAggregator instance.

Documentation Index
-------------------

-  `Basic Usage <#basic-usage>`_
-  `BindTo <#bindto>`_
-  `Decoupling With An Event-Driven
   Architecture <#decoupling-with-an-event-driven-architecture>`_

Basic Usage
-----------

Marionette provides an event aggregator with each application instance:
``MyApp.vent``. You can also instantiate your own event aggregator:

``js myVent = new Marionette.EventAggregator();``

Passing an object literal of options to the constructor function will
extend the event aggregator with those options:

``js myVent = new Marionette.EventAggregator({foo: "bar"}); myVent.foo // => "bar"``

BindTo
------

The ``EventAggregator`` mixes in an
`EventBinder <./marionette.eventbinder.md>`_ object to easily track and
unbind all event callbacks, including inline callback functions.

\`\`\`js vent = new Marionette.EventAggregator();

vent.bindTo(vent, "foo", function(){ alert("bar"); });

vent.unbindAll();

vent.trigger("foo"); // => nothing. all events have been unbound. \`\`\`

Decoupling With An Event-Driven Architecture
--------------------------------------------

You can use an event aggregator to communicate between various modules
of your application, ensuring correct decoupling while also facilitating
functionality that needs more than one of your application's modules.

\`\`\`js var vent = new Marionette.EventAggregator();

vent.on("some:event", function(){ alert("Some event was fired!!!!"); });

vent.trigger("some:event"); \`\`\`

For a more detailed discussion and example of using an event aggregator
with Backbone applications, see the blog post: `References, Routing, and
The Event Aggregator: Coordinating Views In
Backbone.js <http://lostechies.com/derickbailey/2011/07/19/references-routing-and-the-event-aggregator-coordinating-views-in-backbone-js/>`_.