class Response

1. 8.x drupal/core/vendor/guzzle/http/Guzzle/Http/Message/Response.php \Guzzle\Http\Message\Response
2. 8.x drupal/core/vendor/symfony/http-foundation/Symfony/Component/HttpFoundation/Response.php \Symfony\Component\HttpFoundation\Response

BanSubscriber.php in drupal/core/modules/ban/lib/Drupal/ban/EventSubscriber/BanSubscriber.php

Definition of Drupal\ban\EventSubscriber\BanSubscriber.

bootstrap.inc in drupal/core/includes/bootstrap.inc

Functions that need to be loaded on every Drupal request.

Client.php in drupal/core/vendor/symfony/http-kernel/Symfony/Component/HttpKernel/Client.php

ClientTest.php in drupal/core/vendor/symfony/http-kernel/Symfony/Component/HttpKernel/Tests/ClientTest.php

common.inc in drupal/core/includes/common.inc

Common functions that many Drupal modules will need to reference.

... See full list

class Response {

  /**
   * @var \Symfony\Component\HttpFoundation\ResponseHeaderBag
   */
  public $headers;

  /**
   * @var string
   */
  protected $content;

  /**
   * @var string
   */
  protected $version;

  /**
   * @var integer
   */
  protected $statusCode;

  /**
   * @var string
   */
  protected $statusText;

  /**
   * @var string
   */
  protected $charset;

  /**
   * Status codes translation table.
   *
   * The list of codes is complete according to the
   * {@link http://www.iana.org/assignments/http-status-codes/ Hypertext Transfer Protocol (HTTP) Status Code Registry}
   * (last updated 2012-02-13).
   *
   * Unless otherwise noted, the status code is defined in RFC2616.
   *
   * @var array
   */
  public static $statusTexts = array(
    100 => 'Continue',
    101 => 'Switching Protocols',
    102 => 'Processing',
    // RFC2518
    200 => 'OK',
    201 => 'Created',
    202 => 'Accepted',
    203 => 'Non-Authoritative Information',
    204 => 'No Content',
    205 => 'Reset Content',
    206 => 'Partial Content',
    207 => 'Multi-Status',
    // RFC4918
    208 => 'Already Reported',
    // RFC5842
    226 => 'IM Used',
    // RFC3229
    300 => 'Multiple Choices',
    301 => 'Moved Permanently',
    302 => 'Found',
    303 => 'See Other',
    304 => 'Not Modified',
    305 => 'Use Proxy',
    306 => 'Reserved',
    307 => 'Temporary Redirect',
    308 => 'Permanent Redirect',
    // RFC-reschke-http-status-308-07
    400 => 'Bad Request',
    401 => 'Unauthorized',
    402 => 'Payment Required',
    403 => 'Forbidden',
    404 => 'Not Found',
    405 => 'Method Not Allowed',
    406 => 'Not Acceptable',
    407 => 'Proxy Authentication Required',
    408 => 'Request Timeout',
    409 => 'Conflict',
    410 => 'Gone',
    411 => 'Length Required',
    412 => 'Precondition Failed',
    413 => 'Request Entity Too Large',
    414 => 'Request-URI Too Long',
    415 => 'Unsupported Media Type',
    416 => 'Requested Range Not Satisfiable',
    417 => 'Expectation Failed',
    418 => 'I\'m a teapot',
    // RFC2324
    422 => 'Unprocessable Entity',
    // RFC4918
    423 => 'Locked',
    // RFC4918
    424 => 'Failed Dependency',
    // RFC4918
    425 => 'Reserved for WebDAV advanced collections expired proposal',
    // RFC2817
    426 => 'Upgrade Required',
    // RFC2817
    428 => 'Precondition Required',
    // RFC6585
    429 => 'Too Many Requests',
    // RFC6585
    431 => 'Request Header Fields Too Large',
    // RFC6585
    500 => 'Internal Server Error',
    501 => 'Not Implemented',
    502 => 'Bad Gateway',
    503 => 'Service Unavailable',
    504 => 'Gateway Timeout',
    505 => 'HTTP Version Not Supported',
    506 => 'Variant Also Negotiates (Experimental)',
    // RFC2295
    507 => 'Insufficient Storage',
    // RFC4918
    508 => 'Loop Detected',
    // RFC5842
    510 => 'Not Extended',
    // RFC2774
    511 => 'Network Authentication Required',
  );

  /**
   * Constructor.
   *
   * @param string  $content The response content
   * @param integer $status  The response status code
   * @param array   $headers An array of response headers
   *
   * @throws \InvalidArgumentException When the HTTP status code is not valid
   *
   * @api
   */
  public function __construct($content = '', $status = 200, $headers = array()) {
    $this->headers = new ResponseHeaderBag($headers);
    $this
      ->setContent($content);
    $this
      ->setStatusCode($status);
    $this
      ->setProtocolVersion('1.0');
    if (!$this->headers
      ->has('Date')) {
      $this
        ->setDate(new \DateTime(null, new \DateTimeZone('UTC')));
    }
  }

  /**
   * Factory method for chainability
   *
   * Example:
   *
   *     return Response::create($body, 200)
   *         ->setSharedMaxAge(300);
   *
   * @param string  $content The response content
   * @param integer $status  The response status code
   * @param array   $headers An array of response headers
   *
   * @return Response
   */
  public static function create($content = '', $status = 200, $headers = array()) {
    return new static($content, $status, $headers);
  }

  /**
   * Returns the Response as an HTTP string.
   *
   * The string representation of the Response is the same as the
   * one that will be sent to the client only if the prepare() method
   * has been called before.
   *
   * @return string The Response as an HTTP string
   *
   * @see prepare()
   */
  public function __toString() {
    return sprintf('HTTP/%s %s %s', $this->version, $this->statusCode, $this->statusText) . "\r\n" . $this->headers . "\r\n" . $this
      ->getContent();
  }

  /**
   * Clones the current Response instance.
   */
  public function __clone() {
    $this->headers = clone $this->headers;
  }

  /**
   * Prepares the Response before it is sent to the client.
   *
   * This method tweaks the Response to ensure that it is
   * compliant with RFC 2616. Most of the changes are based on
   * the Request that is "associated" with this Response.
   *
   * @param Request $request A Request instance
   *
   * @return Response The current response.
   */
  public function prepare(Request $request) {
    $headers = $this->headers;
    if ($this
      ->isInformational() || in_array($this->statusCode, array(
      204,
      304,
    ))) {
      $this
        ->setContent(null);
    }

    // Content-type based on the Request
    if (!$headers
      ->has('Content-Type')) {
      $format = $request
        ->getRequestFormat();
      if (null !== $format && ($mimeType = $request
        ->getMimeType($format))) {
        $headers
          ->set('Content-Type', $mimeType);
      }
    }

    // Fix Content-Type
    $charset = $this->charset ?: 'UTF-8';
    if (!$headers
      ->has('Content-Type')) {
      $headers
        ->set('Content-Type', 'text/html; charset=' . $charset);
    }
    elseif (0 === strpos($headers
      ->get('Content-Type'), 'text/') && false === strpos($headers
      ->get('Content-Type'), 'charset')) {

      // add the charset
      $headers
        ->set('Content-Type', $headers
        ->get('Content-Type') . '; charset=' . $charset);
    }

    // Fix Content-Length
    if ($headers
      ->has('Transfer-Encoding')) {
      $headers
        ->remove('Content-Length');
    }
    if ($request
      ->isMethod('HEAD')) {

      // cf. RFC2616 14.13
      $length = $headers
        ->get('Content-Length');
      $this
        ->setContent(null);
      if ($length) {
        $headers
          ->set('Content-Length', $length);
      }
    }

    // Fix protocol
    if ('HTTP/1.0' != $request->server
      ->get('SERVER_PROTOCOL')) {
      $this
        ->setProtocolVersion('1.1');
    }

    // Check if we need to send extra expire info headers
    if ('1.0' == $this
      ->getProtocolVersion() && 'no-cache' == $this->headers
      ->get('Cache-Control')) {
      $this->headers
        ->set('pragma', 'no-cache');
      $this->headers
        ->set('expires', -1);
    }
    $this
      ->ensureIEOverSSLCompatibility($request);
    return $this;
  }

  /**
   * Sends HTTP headers.
   *
   * @return Response
   */
  public function sendHeaders() {

    // headers have already been sent by the developer
    if (headers_sent()) {
      return $this;
    }

    // status
    header(sprintf('HTTP/%s %s %s', $this->version, $this->statusCode, $this->statusText));

    // headers
    foreach ($this->headers
      ->allPreserveCase() as $name => $values) {
      foreach ($values as $value) {
        header($name . ': ' . $value, false);
      }
    }

    // cookies
    foreach ($this->headers
      ->getCookies() as $cookie) {
      setcookie($cookie
        ->getName(), $cookie
        ->getValue(), $cookie
        ->getExpiresTime(), $cookie
        ->getPath(), $cookie
        ->getDomain(), $cookie
        ->isSecure(), $cookie
        ->isHttpOnly());
    }
    return $this;
  }

  /**
   * Sends content for the current web response.
   *
   * @return Response
   */
  public function sendContent() {
    echo $this->content;
    return $this;
  }

  /**
   * Sends HTTP headers and content.
   *
   * @return Response
   *
   * @api
   */
  public function send() {
    $this
      ->sendHeaders();
    $this
      ->sendContent();
    if (function_exists('fastcgi_finish_request')) {
      fastcgi_finish_request();
    }
    elseif ('cli' !== PHP_SAPI) {

      // ob_get_level() never returns 0 on some Windows configurations, so if
      // the level is the same two times in a row, the loop should be stopped.
      $previous = null;
      $obStatus = ob_get_status(1);
      while (($level = ob_get_level()) > 0 && $level !== $previous) {
        $previous = $level;
        if ($obStatus[$level - 1] && isset($obStatus[$level - 1]['del']) && $obStatus[$level - 1]['del']) {
          ob_end_flush();
        }
      }
      flush();
    }
    return $this;
  }

  /**
   * Sets the response content.
   *
   * Valid types are strings, numbers, and objects that implement a __toString() method.
   *
   * @param mixed $content
   *
   * @return Response
   *
   * @throws \UnexpectedValueException
   *
   * @api
   */
  public function setContent($content) {
    if (null !== $content && !is_string($content) && !is_numeric($content) && !is_callable(array(
      $content,
      '__toString',
    ))) {
      throw new \UnexpectedValueException(sprintf('The Response content must be a string or object implementing __toString(), "%s" given.', gettype($content)));
    }
    $this->content = (string) $content;
    return $this;
  }

  /**
   * Gets the current response content.
   *
   * @return string Content
   *
   * @api
   */
  public function getContent() {
    return $this->content;
  }

  /**
   * Sets the HTTP protocol version (1.0 or 1.1).
   *
   * @param string $version The HTTP protocol version
   *
   * @return Response
   *
   * @api
   */
  public function setProtocolVersion($version) {
    $this->version = $version;
    return $this;
  }

  /**
   * Gets the HTTP protocol version.
   *
   * @return string The HTTP protocol version
   *
   * @api
   */
  public function getProtocolVersion() {
    return $this->version;
  }

  /**
   * Sets the response status code.
   *
   * @param integer $code HTTP status code
   * @param mixed   $text HTTP status text
   *
   * If the status text is null it will be automatically populated for the known
   * status codes and left empty otherwise.
   *
   * @return Response
   *
   * @throws \InvalidArgumentException When the HTTP status code is not valid
   *
   * @api
   */
  public function setStatusCode($code, $text = null) {
    $this->statusCode = $code = (int) $code;
    if ($this
      ->isInvalid()) {
      throw new \InvalidArgumentException(sprintf('The HTTP status code "%s" is not valid.', $code));
    }
    if (null === $text) {
      $this->statusText = isset(self::$statusTexts[$code]) ? self::$statusTexts[$code] : '';
      return $this;
    }
    if (false === $text) {
      $this->statusText = '';
      return $this;
    }
    $this->statusText = $text;
    return $this;
  }

  /**
   * Retrieves the status code for the current web response.
   *
   * @return integer Status code
   *
   * @api
   */
  public function getStatusCode() {
    return $this->statusCode;
  }

  /**
   * Sets the response charset.
   *
   * @param string $charset Character set
   *
   * @return Response
   *
   * @api
   */
  public function setCharset($charset) {
    $this->charset = $charset;
    return $this;
  }

  /**
   * Retrieves the response charset.
   *
   * @return string Character set
   *
   * @api
   */
  public function getCharset() {
    return $this->charset;
  }

  /**
   * Returns true if the response is worth caching under any circumstance.
   *
   * Responses marked "private" with an explicit Cache-Control directive are
   * considered uncacheable.
   *
   * Responses with neither a freshness lifetime (Expires, max-age) nor cache
   * validator (Last-Modified, ETag) are considered uncacheable.
   *
   * @return Boolean true if the response is worth caching, false otherwise
   *
   * @api
   */
  public function isCacheable() {
    if (!in_array($this->statusCode, array(
      200,
      203,
      300,
      301,
      302,
      404,
      410,
    ))) {
      return false;
    }
    if ($this->headers
      ->hasCacheControlDirective('no-store') || $this->headers
      ->getCacheControlDirective('private')) {
      return false;
    }
    return $this
      ->isValidateable() || $this
      ->isFresh();
  }

  /**
   * Returns true if the response is "fresh".
   *
   * Fresh responses may be served from cache without any interaction with the
   * origin. A response is considered fresh when it includes a Cache-Control/max-age
   * indicator or Expires header and the calculated age is less than the freshness lifetime.
   *
   * @return Boolean true if the response is fresh, false otherwise
   *
   * @api
   */
  public function isFresh() {
    return $this
      ->getTtl() > 0;
  }

  /**
   * Returns true if the response includes headers that can be used to validate
   * the response with the origin server using a conditional GET request.
   *
   * @return Boolean true if the response is validateable, false otherwise
   *
   * @api
   */
  public function isValidateable() {
    return $this->headers
      ->has('Last-Modified') || $this->headers
      ->has('ETag');
  }

  /**
   * Marks the response as "private".
   *
   * It makes the response ineligible for serving other clients.
   *
   * @return Response
   *
   * @api
   */
  public function setPrivate() {
    $this->headers
      ->removeCacheControlDirective('public');
    $this->headers
      ->addCacheControlDirective('private');
    return $this;
  }

  /**
   * Marks the response as "public".
   *
   * It makes the response eligible for serving other clients.
   *
   * @return Response
   *
   * @api
   */
  public function setPublic() {
    $this->headers
      ->addCacheControlDirective('public');
    $this->headers
      ->removeCacheControlDirective('private');
    return $this;
  }

  /**
   * Returns true if the response must be revalidated by caches.
   *
   * This method indicates that the response must not be served stale by a
   * cache in any circumstance without first revalidating with the origin.
   * When present, the TTL of the response should not be overridden to be
   * greater than the value provided by the origin.
   *
   * @return Boolean true if the response must be revalidated by a cache, false otherwise
   *
   * @api
   */
  public function mustRevalidate() {
    return $this->headers
      ->hasCacheControlDirective('must-revalidate') || $this->headers
      ->has('proxy-revalidate');
  }

  /**
   * Returns the Date header as a DateTime instance.
   *
   * @return \DateTime A \DateTime instance
   *
   * @throws \RuntimeException When the header is not parseable
   *
   * @api
   */
  public function getDate() {
    return $this->headers
      ->getDate('Date', new \DateTime());
  }

  /**
   * Sets the Date header.
   *
   * @param \DateTime $date A \DateTime instance
   *
   * @return Response
   *
   * @api
   */
  public function setDate(\DateTime $date) {
    $date
      ->setTimezone(new \DateTimeZone('UTC'));
    $this->headers
      ->set('Date', $date
      ->format('D, d M Y H:i:s') . ' GMT');
    return $this;
  }

  /**
   * Returns the age of the response.
   *
   * @return integer The age of the response in seconds
   */
  public function getAge() {
    if (null !== ($age = $this->headers
      ->get('Age'))) {
      return (int) $age;
    }
    return max(time() - $this
      ->getDate()
      ->format('U'), 0);
  }

  /**
   * Marks the response stale by setting the Age header to be equal to the maximum age of the response.
   *
   * @return Response
   *
   * @api
   */
  public function expire() {
    if ($this
      ->isFresh()) {
      $this->headers
        ->set('Age', $this
        ->getMaxAge());
    }
    return $this;
  }

  /**
   * Returns the value of the Expires header as a DateTime instance.
   *
   * @return \DateTime|null A DateTime instance or null if the header does not exist
   *
   * @api
   */
  public function getExpires() {
    try {
      return $this->headers
        ->getDate('Expires');
    } catch (\RuntimeException $e) {

      // according to RFC 2616 invalid date formats (e.g. "0" and "-1") must be treated as in the past
      return \DateTime::createFromFormat(DATE_RFC2822, 'Sat, 01 Jan 00 00:00:00 +0000');
    }
  }

  /**
   * Sets the Expires HTTP header with a DateTime instance.
   *
   * Passing null as value will remove the header.
   *
   * @param \DateTime|null $date A \DateTime instance or null to remove the header
   *
   * @return Response
   *
   * @api
   */
  public function setExpires(\DateTime $date = null) {
    if (null === $date) {
      $this->headers
        ->remove('Expires');
    }
    else {
      $date = clone $date;
      $date
        ->setTimezone(new \DateTimeZone('UTC'));
      $this->headers
        ->set('Expires', $date
        ->format('D, d M Y H:i:s') . ' GMT');
    }
    return $this;
  }

  /**
   * Returns the number of seconds after the time specified in the response's Date
   * header when the response should no longer be considered fresh.
   *
   * First, it checks for a s-maxage directive, then a max-age directive, and then it falls
   * back on an expires header. It returns null when no maximum age can be established.
   *
   * @return integer|null Number of seconds
   *
   * @api
   */
  public function getMaxAge() {
    if ($this->headers
      ->hasCacheControlDirective('s-maxage')) {
      return (int) $this->headers
        ->getCacheControlDirective('s-maxage');
    }
    if ($this->headers
      ->hasCacheControlDirective('max-age')) {
      return (int) $this->headers
        ->getCacheControlDirective('max-age');
    }
    if (null !== $this
      ->getExpires()) {
      return $this
        ->getExpires()
        ->format('U') - $this
        ->getDate()
        ->format('U');
    }
    return null;
  }

  /**
   * Sets the number of seconds after which the response should no longer be considered fresh.
   *
   * This methods sets the Cache-Control max-age directive.
   *
   * @param integer $value Number of seconds
   *
   * @return Response
   *
   * @api
   */
  public function setMaxAge($value) {
    $this->headers
      ->addCacheControlDirective('max-age', $value);
    return $this;
  }

  /**
   * Sets the number of seconds after which the response should no longer be considered fresh by shared caches.
   *
   * This methods sets the Cache-Control s-maxage directive.
   *
   * @param integer $value Number of seconds
   *
   * @return Response
   *
   * @api
   */
  public function setSharedMaxAge($value) {
    $this
      ->setPublic();
    $this->headers
      ->addCacheControlDirective('s-maxage', $value);
    return $this;
  }

  /**
   * Returns the response's time-to-live in seconds.
   *
   * It returns null when no freshness information is present in the response.
   *
   * When the responses TTL is <= 0, the response may not be served from cache without first
   * revalidating with the origin.
   *
   * @return integer|null The TTL in seconds
   *
   * @api
   */
  public function getTtl() {
    if (null !== ($maxAge = $this
      ->getMaxAge())) {
      return $maxAge - $this
        ->getAge();
    }
    return null;
  }

  /**
   * Sets the response's time-to-live for shared caches.
   *
   * This method adjusts the Cache-Control/s-maxage directive.
   *
   * @param integer $seconds Number of seconds
   *
   * @return Response
   *
   * @api
   */
  public function setTtl($seconds) {
    $this
      ->setSharedMaxAge($this
      ->getAge() + $seconds);
    return $this;
  }

  /**
   * Sets the response's time-to-live for private/client caches.
   *
   * This method adjusts the Cache-Control/max-age directive.
   *
   * @param integer $seconds Number of seconds
   *
   * @return Response
   *
   * @api
   */
  public function setClientTtl($seconds) {
    $this
      ->setMaxAge($this
      ->getAge() + $seconds);
    return $this;
  }

  /**
   * Returns the Last-Modified HTTP header as a DateTime instance.
   *
   * @return \DateTime|null A DateTime instance or null if the header does not exist
   *
   * @throws \RuntimeException When the HTTP header is not parseable
   *
   * @api
   */
  public function getLastModified() {
    return $this->headers
      ->getDate('Last-Modified');
  }

  /**
   * Sets the Last-Modified HTTP header with a DateTime instance.
   *
   * Passing null as value will remove the header.
   *
   * @param \DateTime|null $date A \DateTime instance or null to remove the header
   *
   * @return Response
   *
   * @api
   */
  public function setLastModified(\DateTime $date = null) {
    if (null === $date) {
      $this->headers
        ->remove('Last-Modified');
    }
    else {
      $date = clone $date;
      $date
        ->setTimezone(new \DateTimeZone('UTC'));
      $this->headers
        ->set('Last-Modified', $date
        ->format('D, d M Y H:i:s') . ' GMT');
    }
    return $this;
  }

  /**
   * Returns the literal value of the ETag HTTP header.
   *
   * @return string|null The ETag HTTP header or null if it does not exist
   *
   * @api
   */
  public function getEtag() {
    return $this->headers
      ->get('ETag');
  }

  /**
   * Sets the ETag value.
   *
   * @param string|null $etag The ETag unique identifier or null to remove the header
   * @param Boolean     $weak Whether you want a weak ETag or not
   *
   * @return Response
   *
   * @api
   */
  public function setEtag($etag = null, $weak = false) {
    if (null === $etag) {
      $this->headers
        ->remove('Etag');
    }
    else {
      if (0 !== strpos($etag, '"')) {
        $etag = '"' . $etag . '"';
      }
      $this->headers
        ->set('ETag', (true === $weak ? 'W/' : '') . $etag);
    }
    return $this;
  }

  /**
   * Sets the response's cache headers (validation and/or expiration).
   *
   * Available options are: etag, last_modified, max_age, s_maxage, private, and public.
   *
   * @param array $options An array of cache options
   *
   * @return Response
   *
   * @throws \InvalidArgumentException
   *
   * @api
   */
  public function setCache(array $options) {
    if ($diff = array_diff(array_keys($options), array(
      'etag',
      'last_modified',
      'max_age',
      's_maxage',
      'private',
      'public',
    ))) {
      throw new \InvalidArgumentException(sprintf('Response does not support the following options: "%s".', implode('", "', array_values($diff))));
    }
    if (isset($options['etag'])) {
      $this
        ->setEtag($options['etag']);
    }
    if (isset($options['last_modified'])) {
      $this
        ->setLastModified($options['last_modified']);
    }
    if (isset($options['max_age'])) {
      $this
        ->setMaxAge($options['max_age']);
    }
    if (isset($options['s_maxage'])) {
      $this
        ->setSharedMaxAge($options['s_maxage']);
    }
    if (isset($options['public'])) {
      if ($options['public']) {
        $this
          ->setPublic();
      }
      else {
        $this
          ->setPrivate();
      }
    }
    if (isset($options['private'])) {
      if ($options['private']) {
        $this
          ->setPrivate();
      }
      else {
        $this
          ->setPublic();
      }
    }
    return $this;
  }

  /**
   * Modifies the response so that it conforms to the rules defined for a 304 status code.
   *
   * This sets the status, removes the body, and discards any headers
   * that MUST NOT be included in 304 responses.
   *
   * @return Response
   *
   * @see http://tools.ietf.org/html/rfc2616#section-10.3.5
   *
   * @api
   */
  public function setNotModified() {
    $this
      ->setStatusCode(304);
    $this
      ->setContent(null);

    // remove headers that MUST NOT be included with 304 Not Modified responses
    foreach (array(
      'Allow',
      'Content-Encoding',
      'Content-Language',
      'Content-Length',
      'Content-MD5',
      'Content-Type',
      'Last-Modified',
    ) as $header) {
      $this->headers
        ->remove($header);
    }
    return $this;
  }

  /**
   * Returns true if the response includes a Vary header.
   *
   * @return Boolean true if the response includes a Vary header, false otherwise
   *
   * @api
   */
  public function hasVary() {
    return null !== $this->headers
      ->get('Vary');
  }

  /**
   * Returns an array of header names given in the Vary header.
   *
   * @return array An array of Vary names
   *
   * @api
   */
  public function getVary() {
    if (!($vary = $this->headers
      ->get('Vary'))) {
      return array();
    }
    return is_array($vary) ? $vary : preg_split('/[\\s,]+/', $vary);
  }

  /**
   * Sets the Vary header.
   *
   * @param string|array $headers
   * @param Boolean      $replace Whether to replace the actual value of not (true by default)
   *
   * @return Response
   *
   * @api
   */
  public function setVary($headers, $replace = true) {
    $this->headers
      ->set('Vary', $headers, $replace);
    return $this;
  }

  /**
   * Determines if the Response validators (ETag, Last-Modified) match
   * a conditional value specified in the Request.
   *
   * If the Response is not modified, it sets the status code to 304 and
   * removes the actual content by calling the setNotModified() method.
   *
   * @param Request $request A Request instance
   *
   * @return Boolean true if the Response validators match the Request, false otherwise
   *
   * @api
   */
  public function isNotModified(Request $request) {
    if (!$request
      ->isMethodSafe()) {
      return false;
    }
    $lastModified = $request->headers
      ->get('If-Modified-Since');
    $notModified = false;
    if ($etags = $request
      ->getEtags()) {
      $notModified = (in_array($this
        ->getEtag(), $etags) || in_array('*', $etags)) && (!$lastModified || $this->headers
        ->get('Last-Modified') == $lastModified);
    }
    elseif ($lastModified) {
      $notModified = $lastModified == $this->headers
        ->get('Last-Modified');
    }
    if ($notModified) {
      $this
        ->setNotModified();
    }
    return $notModified;
  }

  // http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html

  /**
   * Is response invalid?
   *
   * @return Boolean
   *
   * @api
   */
  public function isInvalid() {
    return $this->statusCode < 100 || $this->statusCode >= 600;
  }

  /**
   * Is response informative?
   *
   * @return Boolean
   *
   * @api
   */
  public function isInformational() {
    return $this->statusCode >= 100 && $this->statusCode < 200;
  }

  /**
   * Is response successful?
   *
   * @return Boolean
   *
   * @api
   */
  public function isSuccessful() {
    return $this->statusCode >= 200 && $this->statusCode < 300;
  }

  /**
   * Is the response a redirect?
   *
   * @return Boolean
   *
   * @api
   */
  public function isRedirection() {
    return $this->statusCode >= 300 && $this->statusCode < 400;
  }

  /**
   * Is there a client error?
   *
   * @return Boolean
   *
   * @api
   */
  public function isClientError() {
    return $this->statusCode >= 400 && $this->statusCode < 500;
  }

  /**
   * Was there a server side error?
   *
   * @return Boolean
   *
   * @api
   */
  public function isServerError() {
    return $this->statusCode >= 500 && $this->statusCode < 600;
  }

  /**
   * Is the response OK?
   *
   * @return Boolean
   *
   * @api
   */
  public function isOk() {
    return 200 === $this->statusCode;
  }

  /**
   * Is the response forbidden?
   *
   * @return Boolean
   *
   * @api
   */
  public function isForbidden() {
    return 403 === $this->statusCode;
  }

  /**
   * Is the response a not found error?
   *
   * @return Boolean
   *
   * @api
   */
  public function isNotFound() {
    return 404 === $this->statusCode;
  }

  /**
   * Is the response a redirect of some form?
   *
   * @param string $location
   *
   * @return Boolean
   *
   * @api
   */
  public function isRedirect($location = null) {
    return in_array($this->statusCode, array(
      201,
      301,
      302,
      303,
      307,
      308,
    )) && (null === $location ?: $location == $this->headers
      ->get('Location'));
  }

  /**
   * Is the response empty?
   *
   * @return Boolean
   *
   * @api
   */
  public function isEmpty() {
    return in_array($this->statusCode, array(
      201,
      204,
      304,
    ));
  }

  /**
   * Check if we need to remove Cache-Control for ssl encrypted downloads when using IE < 9
   *
   * @link http://support.microsoft.com/kb/323308
   */
  protected function ensureIEOverSSLCompatibility(Request $request) {
    if (false !== stripos($this->headers
      ->get('Content-Disposition'), 'attachment') && preg_match('/MSIE (.*?);/i', $request->server
      ->get('HTTP_USER_AGENT'), $match) == 1 && true === $request
      ->isSecure()) {
      if (intval(preg_replace("/(MSIE )(.*?);/", "\$2", $match[0])) < 9) {
        $this->headers
          ->remove('Cache-Control');
      }
    }
  }

}