emberjs/ember.js — pull request #2258 by rykov (2013-03-10 20:49:07+00:00)
Title: Make Evented#on, #off, and #one chainable

Simple change to make Evented#on, #off, and #one chainable.

Comes in useful with `ember-data`:

record.one('didCreate', function() {
ctrl.transitionToRoute('success');
}).one('becameError', function() {
alert('Bad input');
}).get('transaction').commit();