<?php
/**
 * Zend Framework (http://framework.zend.com/)
 *
 * @link      http://github.com/zendframework/zf2 for the canonical source repository
 * @copyright Copyright (c) 2005-2014 Zend Technologies USA Inc. (http://www.zend.com)
 * @license   http://framework.zend.com/license/new-bsd New BSD License
 */
 
namespace Zend\Mvc\ResponseSender;
 
use Zend\Http\Header\MultipleHeaderInterface;
 
abstract class AbstractResponseSender implements ResponseSenderInterface
{
    /**
     * Send HTTP headers
     *
     * @param  SendResponseEvent $event
     * @return self
     */
    public function sendHeaders(SendResponseEvent $event)
    {
        if (headers_sent() || $event->headersSent()) {
            return $this;
        }
 
        $response = $event->getResponse();
 
        foreach ($response->getHeaders() as $header) {
            if ($header instanceof MultipleHeaderInterface) {
                header($header->toString(), false);
                continue;
            }
            header($header->toString());
        }
 
        $status = $response->renderStatusLine();
        header($status);
 
        $event->setHeadersSent();
        return $this;
    }
}