How to get (needs included) controllers from a template in ember.js?

I have a controller that proxies up a parent controllers model so I can get ask if a property is undefined or not.

import Ember from "ember";

export default Ember.Controller.extend({
    needs: "todos",
    isLoaded: function() {
        return this.get("controllers.todos.model.isLoaded");
    }.property("controllers.todos.model.isLoaded")
});

I'd much prefer to pull this in a template directly but when I do the following my tests hang as it doesn't appear to be legit syntax

{{if controllers.todos.model.isLoaded}}
{{/if}}

Yet I know (in ember 1.11) you can still use controller (singular)

{{#if controller.content}}
{{/if}}

Is it possible to shorthand this computed or even include this in a template? If nothing else I could create a hbs helper (assuming I can get controllers from that scope).