class HttpKernel

1. 9.x drupal/core/lib/Drupal/Core/HttpKernel.php \Drupal\Core\HttpKernel
2. 9.x drupal/core/vendor/symfony/http-kernel/Symfony/Component/HttpKernel/HttpKernel.php \Symfony\Component\HttpKernel\HttpKernel

class HttpKernel extends BaseHttpKernel {
  protected $container;
  private $esiSupport;
  public function __construct(EventDispatcherInterface $dispatcher, ContainerInterface $container, ControllerResolverInterface $controllerResolver) {
    parent::__construct($dispatcher, $controllerResolver);
    $this->container = $container;
  }
  public function handle(Request $request, $type = HttpKernelInterface::MASTER_REQUEST, $catch = true) {
    $request->headers
      ->set('X-Php-Ob-Level', ob_get_level());
    $this->container
      ->enterScope('request');
    $this->container
      ->set('request', $request, 'request');
    try {
      $response = parent::handle($request, $type, $catch);
    } catch (\Exception $e) {
      $this->container
        ->leaveScope('request');
      throw $e;
    }
    $this->container
      ->leaveScope('request');
    return $response;
  }

  /**
   * Forwards the request to another controller.
   *
   * @param string $controller The controller name (a string like BlogBundle:Post:index)
   * @param array  $attributes An array of request attributes
   * @param array  $query      An array of request query parameters
   *
   * @return Response A Response instance
   */
  public function forward($controller, array $attributes = array(), array $query = array()) {
    $attributes['_controller'] = $controller;
    $subRequest = $this->container
      ->get('request')
      ->duplicate($query, null, $attributes);
    return $this
      ->handle($subRequest, HttpKernelInterface::SUB_REQUEST);
  }

  /**
   * Renders a Controller and returns the Response content.
   *
   * Note that this method generates an esi:include tag only when both the standalone
   * option is set to true and the request has ESI capability (@see Symfony\Component\HttpKernel\HttpCache\ESI).
   *
   * Available options:
   *
   *  * attributes: An array of request attributes (only when the first argument is a controller)
   *  * query: An array of request query parameters (only when the first argument is a controller)
   *  * ignore_errors: true to return an empty string in case of an error
   *  * alt: an alternative controller to execute in case of an error (can be a controller, a URI, or an array with the controller, the attributes, and the query arguments)
   *  * standalone: whether to generate an esi:include tag or not when ESI is supported
   *  * comment: a comment to add when returning an esi:include tag
   *
   * @param string $controller A controller name to execute (a string like BlogBundle:Post:index), or a relative URI
   * @param array  $options    An array of options
   *
   * @return string The Response content
   */
  public function render($controller, array $options = array()) {
    $options = array_merge(array(
      'attributes' => array(),
      'query' => array(),
      'ignore_errors' => !$this->container
        ->getParameter('kernel.debug'),
      'alt' => array(),
      'standalone' => false,
      'comment' => '',
    ), $options);
    if (!is_array($options['alt'])) {
      $options['alt'] = array(
        $options['alt'],
      );
    }
    if (null === $this->esiSupport) {
      $this->esiSupport = $this->container
        ->has('esi') && $this->container
        ->get('esi')
        ->hasSurrogateEsiCapability($this->container
        ->get('request'));
    }
    if ($this->esiSupport && (true === $options['standalone'] || 'esi' === $options['standalone'])) {
      $uri = $this
        ->generateInternalUri($controller, $options['attributes'], $options['query']);
      $alt = '';
      if ($options['alt']) {
        $alt = $this
          ->generateInternalUri($options['alt'][0], isset($options['alt'][1]) ? $options['alt'][1] : array(), isset($options['alt'][2]) ? $options['alt'][2] : array());
      }
      return $this->container
        ->get('esi')
        ->renderIncludeTag($uri, $alt, $options['ignore_errors'], $options['comment']);
    }
    if ('js' === $options['standalone']) {
      $uri = $this
        ->generateInternalUri($controller, $options['attributes'], $options['query'], false);
      $defaultContent = null;
      if ($template = $this->container
        ->getParameter('templating.hinclude.default_template')) {
        $defaultContent = $this->container
          ->get('templating')
          ->render($template);
      }
      return $this
        ->renderHIncludeTag($uri, $defaultContent);
    }
    $request = $this->container
      ->get('request');

    // controller or URI?
    if (0 === strpos($controller, '/')) {
      $subRequest = Request::create($request
        ->getUriForPath($controller), 'get', array(), $request->cookies
        ->all(), array(), $request->server
        ->all());
      if ($session = $request
        ->getSession()) {
        $subRequest
          ->setSession($session);
      }
    }
    else {
      $options['attributes']['_controller'] = $controller;
      if (!isset($options['attributes']['_format'])) {
        $options['attributes']['_format'] = $request
          ->getRequestFormat();
      }
      $options['attributes']['_route'] = '_internal';
      $subRequest = $request
        ->duplicate($options['query'], null, $options['attributes']);
      $subRequest
        ->setMethod('GET');
    }
    $level = ob_get_level();
    try {
      $response = $this
        ->handle($subRequest, HttpKernelInterface::SUB_REQUEST, false);
      if (!$response
        ->isSuccessful()) {
        throw new \RuntimeException(sprintf('Error when rendering "%s" (Status code is %s).', $request
          ->getUri(), $response
          ->getStatusCode()));
      }
      if (!$response instanceof StreamedResponse) {
        return $response
          ->getContent();
      }
      $response
        ->sendContent();
    } catch (\Exception $e) {
      if ($options['alt']) {
        $alt = $options['alt'];
        unset($options['alt']);
        $options['attributes'] = isset($alt[1]) ? $alt[1] : array();
        $options['query'] = isset($alt[2]) ? $alt[2] : array();
        return $this
          ->render($alt[0], $options);
      }
      if (!$options['ignore_errors']) {
        throw $e;
      }

      // let's clean up the output buffers that were created by the sub-request
      while (ob_get_level() > $level) {
        ob_get_clean();
      }
    }
  }

  /**
   * Generates an internal URI for a given controller.
   *
   * This method uses the "_internal" route, which should be available.
   *
   * @param string  $controller A controller name to execute (a string like BlogBundle:Post:index), or a relative URI
   * @param array   $attributes An array of request attributes
   * @param array   $query      An array of request query parameters
   * @param boolean $secure
   *
   * @return string An internal URI
   */
  public function generateInternalUri($controller, array $attributes = array(), array $query = array(), $secure = true) {
    if (0 === strpos($controller, '/')) {
      return $controller;
    }
    $path = http_build_query($attributes, '', '&');
    $uri = $this->container
      ->get('router')
      ->generate($secure ? '_internal' : '_internal_public', array(
      'controller' => $controller,
      'path' => $path ?: 'none',
      '_format' => $this->container
        ->get('request')
        ->getRequestFormat(),
    ));
    if ($queryString = http_build_query($query, '', '&')) {
      $uri .= '?' . $queryString;
    }
    return $uri;
  }

  /**
   * Renders an HInclude tag.
   *
   * @param string $uri A URI
   * @param string $defaultContent Default content
   */
  public function renderHIncludeTag($uri, $defaultContent = null) {
    return sprintf('<hx:include src="%s">%s</hx:include>', $uri, $defaultContent);
  }
  public function hasEsiSupport() {
    return $this->esiSupport;
  }

}