Ember-CLI-101 sortable issue

adapters_application.js

import DS from 'ember-data';

export default DS.ActiveModelAdapter.extend({
	namespace: 'api/v4',
	coalesceFindRequests: true
});

controllers_friends_index.js

import Ember from 'ember';

export default Ember.ArrayController.extend({
	sortAscending: false,
	sortBy: 'fullName',
	sortProperties: Ember.computed('sortBy', function() {
		return [this.get('sortBy')];
	}),
	actions: {
		setSortBy: function(fieldName) {
			console.log('setting sort by to '+fieldName);
			this.set('sortBy', fieldName);
			this.toggleProperty('sortAscending');
			return false;
		}
	}
});

fixed_friends_index.hbs

<h1>{{model.length}} Friends</h1>

<table class="primary">
	<thead>
		<tr>
			<th {{action "setSortBy" "fullName"}}>Name</th>
			<th {{action "setSortBy" "totalArticles"}}>Articles</th>
			<th></th>
		</tr>
	</thead>
	<tbody>
		{{#each}}
			<tr>
				<td>{{link-to fullName 'articles' this}}</td>
				<td>{{totalArticles}}</td>
				<td><a href="#" {{action "delete" this}}>Delete</a></td>
			</tr>
		{{/each}}
	</tbody>
</table>

models_friend.js

import Ember from 'ember';
import DS from 'ember-data';

export default DS.Model.extend({
  articles: DS.hasMany('article', {async: true}),
  email: DS.attr('string'),
  firstName: DS.attr('string'),
  lastName: DS.attr('string'),
  totalArticles: DS.attr('number'),
  twitter: DS.attr('string'),
  fullName: Ember.computed('firstName', 'lastName', function() {
  	return this.get('firstName') + ' ' + this.get('lastName');
  })
});

routes_friends_index.js

import Ember from 'ember';

export default Ember.Route.extend({
	queryParams: {
		sortBy: {
			refreshModel: true
		},
		sortAscending: {
			refreshModel: true
		}
	},
	model: function() {
		return this.store.find('friend');
	},
	actions: {
	}
});

templates_friends_index.hbs

<h1>{{model.length}} Friends</h1>

<table class="primary">
	<thead>
		<tr>
			<th {{action "setSortBy" "fullName"}}>Name</th>
			<th {{action "setSortBy" "totalArticles"}}>Articles</th>
			<th></th>
		</tr>
	</thead>
	<tbody>
		{{#each friend in model}}
			<tr>
				<td>{{link-to friend.fullName 'articles' friend}}</td>
				<td>{{friend.totalArticles}}</td>
				<td><a href="#" {{action "delete" friend}}>Delete</a></td>
			</tr>
		{{/each}}
	</tbody>
</table>