class FragmentHandler

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

class FragmentHandler {
  private $debug;
  private $renderers;
  private $request;

  /**
   * Constructor.
   *
   * @param FragmentRendererInterface[] $renderers An array of FragmentRendererInterface instances
   * @param Boolean                     $debug     Whether the debug mode is enabled or not
   */
  public function __construct(array $renderers = array(), $debug = false) {
    $this->renderers = array();
    foreach ($renderers as $renderer) {
      $this
        ->addRenderer($renderer);
    }
    $this->debug = $debug;
  }

  /**
   * Adds a renderer.
   *
   * @param FragmentRendererInterface $renderer A FragmentRendererInterface instance
   */
  public function addRenderer(FragmentRendererInterface $renderer) {
    $this->renderers[$renderer
      ->getName()] = $renderer;
  }

  /**
   * Sets the current Request.
   *
   * @param Request $request The current Request
   */
  public function setRequest(Request $request = null) {
    $this->request = $request;
  }

  /**
   * Renders a URI and returns the Response content.
   *
   * Available options:
   *
   *  * ignore_errors: true to return an empty string in case of an error
   *
   * @param string|ControllerReference $uri      A URI as a string or a ControllerReference instance
   * @param string                     $renderer The renderer name
   * @param array                      $options  An array of options
   *
   * @return string|null The Response content or null when the Response is streamed
   *
   * @throws \InvalidArgumentException when the renderer does not exist
   * @throws \RuntimeException         when the Response is not successful
   */
  public function render($uri, $renderer = 'inline', array $options = array()) {
    if (!isset($options['ignore_errors'])) {
      $options['ignore_errors'] = !$this->debug;
    }
    if (!isset($this->renderers[$renderer])) {
      throw new \InvalidArgumentException(sprintf('The "%s" renderer does not exist.', $renderer));
    }
    if (null === $this->request) {
      throw new \LogicException('Rendering a fragment can only be done when handling a master Request.');
    }
    return $this
      ->deliver($this->renderers[$renderer]
      ->render($uri, $this->request, $options));
  }

  /**
   * Delivers the Response as a string.
   *
   * When the Response is a StreamedResponse, the content is streamed immediately
   * instead of being returned.
   *
   * @param Response $response A Response instance
   *
   * @return string|null The Response content or null when the Response is streamed
   *
   * @throws \RuntimeException when the Response is not successful
   */
  protected function deliver(Response $response) {
    if (!$response
      ->isSuccessful()) {
      throw new \RuntimeException(sprintf('Error when rendering "%s" (Status code is %s).', $this->request
        ->getUri(), $response
        ->getStatusCode()));
    }
    if (!$response instanceof StreamedResponse) {
      return $response
        ->getContent();
    }
    $response
      ->sendContent();
  }

}