te, you'll continue to see the templates from the previous route
until the model finish loading, and then, boom, suddenly all the
templates for <code>slow-model</code> load.</p>
<p>So, how can we provide some visual feedback during the transition?</p>
<p>Simply define a template called <code>loading</code> (and optionally a corresponding route)
that Ember will transition to. The
intermediate transition into the loading substate happens immediately
(synchronously), the URL won't be updated, and, unlike other