Custom substates in router?

is it possible to create a custom substate in each route like the error/loading substates?

It’s coming in Ember 1.11, it’s in the beta right now: Ember.js 1.10.0 and 1.11 Beta Released (almost at the bottom, named substates).

You also have to explicitly add the loading route to your routes

this.route('todos');
this.route('todos_loading');

but I think that’s a bug.

Edit: If you mean another type of substate, I really don’t know. There’s an intermediateTransitionTo() method on the router, maybe that’ll help.