Ember js controller with computed properties

gistfile1.js

App.DashboardController = Em.ArrayController.extend({
	content: [],
	
	// contentRecent: Em.ArrayController.create({
	// 	content: [],
	// 	count: Em.computed(function() {
	// 		return this.get('content').length;
	// 	}).property('content.@each')
	// }),
	
	// contentWhatsnew: Em.ArrayController.create({
	// 	content: [],
	// 	count: Em.computed(function() {
	// 		return this.get('content').length;
	// 	}).property('content.@each')
	// }),
	
	// contentMessages: Em.ArrayController.create({
	// 	content: [],
	// 	count: Em.computed(function() {
	// 		return this.get('content').length;
	// 	}).property('content.@each')
	// }),

	// contentActivities: Em.ArrayController.create({
	// 	content: [],
	// 	count: Em.computed(function() {
	// 		return this.get('content').length;
	// 	}).property('content.@each')
	// }),
	
	templatehtmltext: '',
	
	init: function() {
		var me = this;
		//me.loadContent();
	},
	
	loadContent: function() {
		var me = this;
		
		me.set('content', []);
		var recentItemsController = App.RecentItemsController.create();
		recentItemsController.set('content', []);
		// App.WhatsNew.set('content', []);
		// App.Messages.set('content', []);
		// App.Activities.set('content', []);
		
		$.post('data/Ajax.php', {'class': 'App', 'method': 'getDashboardObjects', 'params': ['']}, function(data) {
			if (data) {
				if (data.templatehtmltext) me.set('templatehtmltext', data.templatehtmltext);
				if (data['recent']) recentItemsController.pushObjects(data['recent']);
				// if (data['whatsnew']) me.get('contentWhatsnew').pushObjects(data['whatsnew']);
				// if (data['messages']) me.get('contentMessages').pushObjects(data['messages']);
				// if (data['activities']) me.get('contentActivities').pushObjects(data['activities']);
			}
		}, 'json');
		
	}	
});


App.RecentItemsController = Em.ArrayController.extend({
  content: [],
  count: Em.computed(function() {
    return this.get('content').length;
  }).property('content.@each')
});

App.WhatsNewController = Em.ArrayController.extend({
  content: [],
  count: Em.computed(function() {
    return this.get('content').length;
  }).property('content.@each')
});

App.MessagesController = Em.ArrayController.extend({
  content: [],
  count: Em.computed(function() {
    return this.get('content').length;
  }).property('content.@each')
});

App.ActivitiesController = Em.ArrayController.extend({
  content: [],
  count: Em.computed(function() {
    return this.get('content').length;
  }).property('content.@each')
});