Asynchronous Routing
This section covers some more advanced features of the router and its capability for handling complex async logic within your app.
A Word on Promises...
Ember's approach to handling asynchronous logic in the router makes heavy use of the concept of Promises. In short, promises are objects that represent an eventual value. A promise can either fulfill (successfully resolve the value) or reject (fail to resolve the value). The way to retrieve this eventual value, or handle
