gistfile1.php

<?php
namespace Application\Controller;

use Zend\View\Model\ViewModel;
use Core\Controller\ActionController;
use Zend\Paginator\Paginator;
use Zend\Paginator\Adapter\DbSelect as PaginatorDbSelectAdapter;

use Symfony\Component\Serializer\Serializer;
use Symfony\Component\Serializer\Normalizer\GetSetMethodNormalizer;
use Symfony\Component\Serializer\Encoder\JsonEncoder;
use Symfony\Component\Serializer\Encoder\XmlEncoder;

/**
 * Controlador que gerencia os posts
 * 
 * @category Application
 * @package Controller
 * @author  Elton Minetto <eminetto@coderockr.com>
 */
class IndexController extends ActionController
{
    /**
     * Mostra os posts cadastrados
     * @return void
     */
    public function indexAction()
    {
        $post = $this->getTable('Application\Model\Post');
        $sql = $post->getSql();
        $select = $sql->select();

        $paginatorAdapter = new PaginatorDbSelectAdapter($select, $sql);
        $paginator = new Paginator($paginatorAdapter);
        $paginator->setCurrentPageNumber($this->params()->fromRoute('page'));
        $paginator->setItemCountPerPage(10);

        return new ViewModel(array(
            'posts' => $paginator
        ));
    }

    /**
     * Retorna os comentários de um post
     * @return Zend\Http\Response 
     */
    public function commentsAction()
    {
        $id = (int) $this->params()->fromRoute('id', 0);
        if ($id == 0) {
            throw new \Exception("Código obrigatório");
        }
        $format = $this->params()->fromRoute('format', 'json');

        $where = array('post_id' => $id);
        $comments = $this->getTable('Application\Model\Comment')
                         ->fetchAll(null, $where)
                         ->toArray();

        $serializer = new Serializer(
            array(new GetSetMethodNormalizer()), 
            array(
                'xml' => new XmlEncoder(),
                'json' => new JsonEncoder()
            )
        );
        if ($format == 'json') {
            $content = $serializer->serialize($comments, 'json');
        }
        if ($format == 'xml') {
            $content = $serializer->serialize($comments, 'xml');
        }

        $response = $this->getResponse();
        $response->setStatusCode(200);
        $response->setContent($content);
        $response->getHeaders()->addHeaderLine('Content-Type', 'application/' . $format);
        return $response;
    }
}