public function CacheControlOverrideSubscriber::onRespond in Cache Control Override 8

Overrides cache control header if any of override methods are enabled.

Parameters

\Symfony\Component\HttpKernel\Event\FilterResponseEvent $event: The event to process.

File

src/EventSubscriber/CacheControlOverrideSubscriber.php, line 22

Class

CacheControlOverrideSubscriber

Cache Control Override.

Namespace

Drupal\cache_control_override\EventSubscriber

Code

public function onRespond(FilterResponseEvent $event) {
  if (!$event
    ->isMasterRequest()) {
    return;
  }
  $response = $event
    ->getResponse();

  // If the current response isn't an implementation of the
  // CacheableResponseInterface, then there is nothing we can override.
  if (!$response instanceof CacheableResponseInterface) {
    return;
  }

  // If FinishResponseSubscriber didn't set the response as cacheable, then
  // don't override anything.
  if (!$response->headers
    ->hasCacheControlDirective('max-age') || !$response->headers
    ->hasCacheControlDirective('public')) {
    return;
  }
  $max_age = $response
    ->getCacheableMetadata()
    ->getCacheMaxAge();

  // We treat permanent cache max-age as default therefore we don't override
  // the max-age.
  if ($max_age != Cache::PERMANENT) {
    $response->headers
      ->set('Cache-Control', 'public, max-age=' . $max_age);
  }
}