A simple, shortened example of needs in a controller in Ember.js

example.js

App.TestController = Em.Controller.extend({
  needs: 'user',
  
  userController: (function() {
    return this.controllerFor('user');
  }).property(),
  
  someObserver: (function() {
    @get('userController.someValue')
  }).observes('userController.someValue')
});