RSS Feed with CodeIgniter + Twig

gistfile1.txt

rss.xml:

<?xml version="1.0"?>
<rss version="2.0">
    <channel>
        <title>your title</title>
        <link>http://www.example.com/</link>
        <description>your description</description>
        <language>en-us</language>
        <lastBuildDate>{{updated}}</lastBuildDate>
        {% for post in posts %}
        <item>
            <title>{{post.title}}</title>
            <author>David Wong</author>
            <pubDate>{{post.date}}</pubDate>
            <link>{{post.url}}</link>
            <comments>{{post.url}}#comments</comments>
            <description>
                <![CDATA[
                    {{post.text|nl2br}}
                ]]>
            </description>
        </item>
        {% endfor %}
    </channel>
</rss>

in a controller:

public function feed(){
// load
$this->load->helper('url');

// get posts
$this->db->order_by('id', 'desc');
$query = $this->db->get('posts', 20);
$posts = $query->result();

// format
foreach ($posts as $post)
{
    $web = url_title($post->title, '-', TRUE);
    $post->url = 'http://www.example.com/article/'.$post->id.'/'.$web.'/';
    $post->date = date('r', strtotime($post->date));
}

$data = array(
    'updated' => $posts[0]->date,
    'posts' => $posts
);

// output cached
$output = $this->twig->render('rss.xml', $data);
$this->output->set_output($output);
$this->output->cache(60); // 1 hour

}