Backbone View Event Types

Today I read through Derick Bailey's excellent post on memory management in Backbone view code.  I was a bit confused by all the different ways to register and un-register events and what they were all for.  Specifically I was confused by his close() method, used to clean up view events.

Why was unbind() needed in addition to remove()?   Why was stopListening() not needed?

So I put together a simple guide for myself.

• undelegateEvents() calls off() for all events registered through backbone's delegateEvents()
• usually this means all events named in the 'events' object passed to a view, which hande DOM events
• code: http://backbonejs.org/docs/backbone.html#section-139
• delegateEvents() works differently from directly binding events with jquery's on()
• code: http://backbonejs.org/docs/backbone.html#section-138
• namespaces events under .delegateEvents{view cid} 
• this makes it easy to remove events only for this view with undelegateEvents() 
• stopListening() calls off() for all events registered through backbone, on this._listeningTo
• usually these are non-DOM events
• code: http://backbonejs.org/docs/backbone.html#section-23
• unbind() is the same as off() now
• can captures anything that doesn't go through listenTo() (and everything that does)
• code: http://backbonejs.org/docs/backbone.html#section-30
• docs: http://backbonejs.org/#Events-listenTo
• the main advantage of using listenTo() is easy cleanup
• remove() delegates to jquery's remove()
• docs: http://api.jquery.com/remove/
• removes DOM elements, bound events, and data

After putting this together the code makes more sense.

You do need to call unbind() in addition to remove() because remove() handles DOM events and unbind() handles Backbone events.

You don't need to call stopListening() because unbind() catches everything stopListening() would catch.  You don't need undelegateEvents() because jquery's remove() removes all of the events on that DOM element for you.

Hope that helps.