symfony/src/Symfony/Component/HttpFoundation/ResponseHeaderBag.php

<?php

namespace Symfony\Component\HttpFoundation;

/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier <fabien.potencier@symfony-project.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

/**
 * ResponseHeaderBag is a container for Response HTTP headers.
 *
 * @author Fabien Potencier <fabien.potencier@symfony-project.com>
 */
class ResponseHeaderBag extends HeaderBag
{
    protected $computedCacheControl = array();

    /**
     * {@inheritdoc}
     */
    public function replace(array $headers = array())
    {
        parent::replace($headers);

        if (!isset($this->headers['cache-control'])) {
            $this->set('cache-control', '');
        }
    }

    /**
     * {@inheritdoc}
     */
    public function set($key, $values, $replace = true)
    {
        parent::set($key, $values, $replace);

        // ensure the cache-control header has sensible defaults
        if ('cache-control' === strtr(strtolower($key), '_', '-')) {
            $computed = $this->computeCacheControlValue();
            $this->headers['cache-control'] = array($computed);
            $this->computedCacheControl = $this->parseCacheControl($computed);
        }
    }

    /**
     * {@inheritdoc}
     */
    public function remove($key)
    {
        parent::remove($key);

        if ('cache-control' === strtr(strtolower($key), '_', '-')) {
            $this->computedCacheControl = array();
        }
    }

    /**
     * {@inheritdoc}
     */
    public function setCookie($name, $value, $domain = null, $expires = null, $path = '/', $secure = false, $httponly = true)
    {
        $this->validateCookie($name, $value);

        $cookie = sprintf('%s=%s', $name, urlencode($value));

        if (null !== $expires) {
            if (is_numeric($expires)) {
                $expires = (int) $expires;
            } elseif ($expires instanceof \DateTime) {
                $expires = $expires->getTimestamp();
            } else {
                $expires = strtotime($expires);
                if (false === $expires || -1 == $expires) {
                    throw new \InvalidArgumentException(sprintf('The "expires" cookie parameter is not valid.', $expires));
                }
            }

            $cookie .= '; expires='.substr(\DateTime::createFromFormat('U', $expires, new \DateTimeZone('UTC'))->format('D, d-M-Y H:i:s T'), 0, -5);
        }

        if ($domain) {
            $cookie .= '; domain='.$domain;
        }

        $cookie .= '; path='.$path;

        if ($secure) {
            $cookie .= '; secure';
        }

        if ($httponly) {
            $cookie .= '; httponly';
        }

        $this->set('Set-Cookie', $cookie, false);
    }

    /**
     * {@inheritdoc}
     */
    public function hasCacheControlDirective($key)
    {
        return array_key_exists($key, $this->computedCacheControl);
    }

    /**
     * {@inheritdoc}
     */
    public function getCacheControlDirective($key)
    {
        return array_key_exists($key, $this->computedCacheControl) ? $this->computedCacheControl[$key] : null;
    }

    /**
     * Returns the calculated value of the cache-control header.
     *
     * This considers several other headers and calculates or modifies the
     * cache-control header to a sensible, conservative value.
     *
     * @return string
     */
    protected function computeCacheControlValue()
    {
        if (!$this->cacheControl && !$this->has('ETag') && !$this->has('Last-Modified') && !$this->has('Expires')) {
            return 'no-cache';
        }

        if (!$this->cacheControl) {
            // conservative by default
            return 'private, max-age=0, must-revalidate';
        }

        $header = $this->getCacheControlHeader();
        if (isset($this->cacheControl['public']) || isset($this->cacheControl['private'])) {
            return $header;
        }

        // public if s-maxage is defined, private otherwise
        if (!isset($this->cacheControl['s-maxage'])) {
            return $header.', private';
        }

        return $header;
    }
}