public function CacheControlEventSubscriber::setHeaderCacheControl in HTTP Cache Control 8

Same name and namespace in other branches

1. 8.2 src/EventSubscriber/CacheControlEventSubscriber.php \Drupal\http_cache_control\EventSubscriber\CacheControlEventSubscriber::setHeaderCacheControl()

Set http cache control headers.

File

src/EventSubscriber/CacheControlEventSubscriber.php, line 17

Class

CacheControlEventSubscriber

Subscriber for adding http cache control headers.

Namespace

Drupal\http_cache_control\EventSubscriber

Code

public function setHeaderCacheControl(FilterResponseEvent $event) {
  $config = \Drupal::service('config.factory')
    ->get('system.performance');
  $response = $event
    ->getResponse();
  if (!$response
    ->isCacheable()) {
    return;
  }
  $max_age = $response
    ->getMaxAge();
  switch ($response
    ->getStatusCode()) {
    case 404:
      $ttl = $config
        ->get('cache.http.404_max_age', $max_age);
      break;
    case 302:
      $ttl = $config
        ->get('cache.http.302_max_age', $max_age);
      break;
    case 301:
      $ttl = $config
        ->get('cache.http.301_max_age', $max_age);
      break;
    default:
      $ttl = $config
        ->get('cache.page.max_age');
      break;
  }

  // Allow modules that set their own max age to retain it.
  // If a response max-age is different to the page max-age
  // then this suggests the max-age has already been manipulated.
  if ($max_age != $config
    ->get('cache.page.max_age')) {
    $ttl = $max_age;
  }
  $response
    ->setSharedMaxAge($ttl);
  $response
    ->setClientTtl($config
    ->get('cache.http.max_age'));
  if ($response
    ->getStatusCode() >= 500) {
    $response
      ->setSharedMaxAge($config
      ->get('cache.http.5xx_max_age'));
  }
  elseif ($response
    ->getStatusCode() < 400) {

    // Add stale-if-error directive.
    if ($seconds = $config
      ->get('cache.http.stale_if_error')) {
      $response->headers
        ->addCacheControlDirective('stale-if-error', $seconds);
    }

    // Add stale-while-revalidate directive.
    if ($seconds = $config
      ->get('cache.http.stale_while_revalidate')) {
      $response->headers
        ->addCacheControlDirective('stale-while-revalidate', $seconds);
    }
  }
}