navigation.js

var NavigationController = Ember.ArrayController.extend({
  content: Ember.A([
    Ember.Object.create({title: "About", location: 'about', active: null}),
    Ember.Object.create({title: "Projects", location: 'projects', active: null})
  ]),
  title: "Almighty Machine",
  activeLink: null,
  activeLinkObserver: function() {
    var activeLink = this.get('activeLink');
    var content = this.get('model');
    content.setEach('active', false);
    if(typeof activeLink !== "undefined"  && activeLink !== null) {
      content.findBy('location', activeLink).set('active', true);
    }
  }.observes('activeLink')
});

export default NavigationController;