Chris@0: <?php
Chris@0: 
Chris@0: namespace Drupal\big_pipe\Render;
Chris@0: 
Chris@0: use Drupal\Core\Render\HtmlResponse;
Chris@0: 
Chris@0: /**
Chris@0:  * A response that is sent in chunks by the BigPipe service.
Chris@0:  *
Chris@0:  * Note we cannot use \Symfony\Component\HttpFoundation\StreamedResponse because
Chris@0:  * it makes the content inaccessible (hidden behind a callback), which means no
Chris@0:  * middlewares are able to modify the content anymore.
Chris@0:  *
Chris@0:  * @see \Drupal\big_pipe\Render\BigPipe
Chris@0:  *
Chris@0:  * @internal
Chris@0:  *   This is a temporary solution until a generic response emitter interface is
Chris@0:  *   created in https://www.drupal.org/node/2577631. Only code internal to
Chris@0:  *   BigPipe should instantiate or type hint to this class.
Chris@0:  */
Chris@0: class BigPipeResponse extends HtmlResponse {
Chris@0: 
Chris@0:   /**
Chris@0:    * The BigPipe service.
Chris@0:    *
Chris@0:    * @var \Drupal\big_pipe\Render\BigPipe
Chris@0:    */
Chris@0:   protected $bigPipe;
Chris@0: 
Chris@0:   /**
Chris@0:    * The original HTML response.
Chris@0:    *
Chris@0:    * Still contains placeholders. Its cacheability metadata and attachments are
Chris@0:    * for everything except the placeholders (since those are not yet rendered).
Chris@0:    *
Chris@0:    * @see \Drupal\Core\Render\StreamedResponseInterface
Chris@0:    * @see ::getStreamedResponse()
Chris@0:    *
Chris@0:    * @var \Drupal\Core\Render\HtmlResponse
Chris@0:    */
Chris@0:   protected $originalHtmlResponse;
Chris@0: 
Chris@0:   /**
Chris@0:    * Constructs a new BigPipeResponse.
Chris@0:    *
Chris@0:    * @param \Drupal\Core\Render\HtmlResponse $response
Chris@0:    *   The original HTML response.
Chris@0:    */
Chris@0:   public function __construct(HtmlResponse $response) {
Chris@0:     parent::__construct('', $response->getStatusCode(), []);
Chris@0: 
Chris@0:     $this->originalHtmlResponse = $response;
Chris@0: 
Chris@0:     $this->populateBasedOnOriginalHtmlResponse();
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Returns the original HTML response.
Chris@0:    *
Chris@0:    * @return \Drupal\Core\Render\HtmlResponse
Chris@0:    *   The original HTML response.
Chris@0:    */
Chris@0:   public function getOriginalHtmlResponse() {
Chris@0:     return $this->originalHtmlResponse;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Populates this BigPipeResponse object based on the original HTML response.
Chris@0:    */
Chris@0:   protected function populateBasedOnOriginalHtmlResponse() {
Chris@0:     // Clone the HtmlResponse's data into the new BigPipeResponse.
Chris@0:     $this->headers = clone $this->originalHtmlResponse->headers;
Chris@0:     $this
Chris@0:       ->setStatusCode($this->originalHtmlResponse->getStatusCode())
Chris@0:       ->setContent($this->originalHtmlResponse->getContent())
Chris@0:       ->setAttachments($this->originalHtmlResponse->getAttachments())
Chris@0:       ->addCacheableDependency($this->originalHtmlResponse->getCacheableMetadata());
Chris@0: 
Chris@0:     // A BigPipe response can never be cached, because it is intended for a
Chris@0:     // single user.
Chris@0:     // @see http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.9.1
Chris@0:     $this->setPrivate();
Chris@0: 
Chris@0:     // Inform surrogates how they should handle BigPipe responses:
Chris@0:     // - "no-store" specifies that the response should not be stored in cache;
Chris@0:     //   it is only to be used for the original request
Chris@0:     // - "content" identifies what processing surrogates should perform on the
Chris@0:     //   response before forwarding it. We send, "BigPipe/1.0", which surrogates
Chris@0:     //   should not process at all, and in fact, they should not even buffer it
Chris@0:     //   at all.
Chris@0:     // @see http://www.w3.org/TR/edge-arch/
Chris@0:     $this->headers->set('Surrogate-Control', 'no-store, content="BigPipe/1.0"');
Chris@0: 
Chris@0:     // Add header to support streaming on NGINX + php-fpm (nginx >= 1.5.6).
Chris@0:     $this->headers->set('X-Accel-Buffering', 'no');
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Sets the BigPipe service to use.
Chris@0:    *
Chris@0:    * @param \Drupal\big_pipe\Render\BigPipe $big_pipe
Chris@0:    *   The BigPipe service.
Chris@0:    */
Chris@0:   public function setBigPipeService(BigPipe $big_pipe) {
Chris@0:     $this->bigPipe = $big_pipe;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function sendContent() {
Chris@0:     $this->bigPipe->sendContent($this);
Chris@0: 
Chris@0:     // All BigPipe placeholders are processed, so update this response's
Chris@0:     // attachments.
Chris@0:     unset($this->attachments['big_pipe_placeholders']);
Chris@0:     unset($this->attachments['big_pipe_nojs_placeholders']);
Chris@0: 
Chris@0:     return $this;
Chris@0:   }
Chris@0: 
Chris@0: }