statedview.js adds a simple, event triggered state machine to Backbone.View. This allows relatively complex UI behavior to be easily modeled and modified without the need for event handlers and state booleans ('var isOpen') all over the place.

By extending Backbone.StatedView rathar then Backbone.View you gain state which is the current state the view is in and states which is a hash that describes the state graph for this view. It is a hash of

{
    'event selector': {                     // <-- The trigger event and selector to attach it to
        'startState' : 'endState'           // <-- A transition this trigger can cause
        'startState2' : 'endState2'         // <-- Another transition this trigger can cause
    },
    'event2 selector2': {
        'startState2' : 'endState2'
        'startState3' : 'endState3'
    }
}

and so on.

A trigger event - like click .closeButton for example - is captured automatically and the matched against its state map. If a match for the current state is found, the view is updated to the end state and a method of the same name is called, allowing you to act of the transition.

... was written in a couple of hours. Only tested with jQuery 1.5 and the latest underscore.js / backbone.js. Feedback appreciated.