Issue #2943351 by jeffschuler: Simplify Views display plugin by deriving from RestExport class.

namespace Drupal\views_geojson\Plugin\views\display;

use Drupal;

use Drupal\Core\Cache\CacheableMetadata;

use Drupal\Core\Cache\CacheableResponse;

use Drupal\Core\Render\RenderContext;

use Drupal\views\Plugin\views\display\PathPluginBase;

use Drupal\views\Plugin\views\display\ResponseDisplayPluginInterface;

use Drupal\views\Render\ViewsRenderPipelineMarkup;

use Drupal\views\ViewExecutable;

use Symfony\Component\Routing\RouteCollection;

use Drupal\rest\Plugin\views\display\RestExport;

/**

 * The plugin that handles Data response callbacks for REST resources.

 * The plugin that handles Data response callbacks for GeoJSON REST resources.

 *

 * @ingroup views_display_plugins

 *

 *     returns_response=TRUE

 * )

 */

class GeoJsonExport extends PathPluginBase implements ResponseDisplayPluginInterface {

  /**

   * Overrides the content type of the data response, if needed.

   *

   * @var string

   */

  protected $contentType = 'json';

  /**

   * The mime type for the response.

   *

   * @var string

   */

  protected $mimeType;

  /**

   * Uses AJAX variable.

   *

   * Overrides \Drupal\views\Plugin\views\display\DisplayPluginBase::$usesAJAX.

   *

   * @var bool

   */

  protected $usesAJAX = FALSE;

  /**

   * Uses Areas variable.

   *

   * Overrides \Drupal\views\Plugin\views\display\DisplayPluginBase::$usesAreas.

   *

   * @var bool

   */

  protected $usesAreas = FALSE;

  /**

   * Uses More variable.

   *

   * Overrides \Drupal\views\Plugin\views\display\DisplayPluginBase::$usesMore.

   *

   * @var bool

   */

  protected $usesMore = FALSE;

  /**

   * Uses Options variable.

   *

   * Overrides \Drupal\views\Plugin\views\display\DisplayPluginBase::$usesAreas.

   *

   * @var bool

   */

  protected $usesOptions = FALSE;

  /**

   * Uses Pager variable.

   *

   * Overrides \Drupal\views\Plugin\views\display\DisplayPluginBase::$usesPager.

   *

   * @var bool

   */

  protected $usesPager = FALSE;

  /**

   * {@inheritdoc}

   */

  public static function buildResponse($view_id, $display_id, array $args = []) {

    $build = static::buildBasicRenderable($view_id, $display_id, $args);

    // Set up an empty response, so for example RSS can set the proper

    // Content-Type header.

    $response = new CacheableResponse('', 200);

    $build['#response'] = $response;

    /** @var \Drupal\Core\Render\RendererInterface $renderer */

    $renderer = Drupal::service('renderer');

    $output = (string) $renderer->renderRoot($build);

    if (empty($output)) {

      // Throw new NotFoundHttpException();

    }

    $response->setContent($output);

    $cache_metadata = CacheableMetadata::createFromRenderArray($build);

    $response->addCacheableDependency($cache_metadata);

    return $response;

  }

  /**

   * {@inheritdoc}

   */

  public function collectRoutes(RouteCollection $collection) {

    parent::collectRoutes($collection);

    $view_id = $this->view->storage->id();

    $display_id = $this->display['id'];

    if ($route = $collection->get("view.{$view_id}.{$display_id}")) {

      $style_plugin = $this->getPlugin('style');

      // REST exports should only respond to get methods.

      $requirements = [

        '_method' => 'GET',

        '_format' => 'json',

      ];

      // Add the new requirements to the route.

      $route->addRequirements($requirements);

    }

  }

  /**

   * {@inheritdoc}

   */

  public function displaysExposed() {

    return FALSE;

  }

  /**

   * {@inheritdoc}

   */

  public function execute() {

    parent::execute();

    return $this->view->render();

  }

  /**

   * Gets the content type.

   *

   * @return string

   *   The content type machine name. E.g. 'json'.

   */

  public function getContentType() {

    return $this->contentType;

  }

  /**

   * Gets the mime type.

   *

   * This will return any overridden mime type, otherwise returns the mime type

   * from the request.

   *

   * @return string

   *   The response mime type. E.g. 'application/json'.

   */

  public function getMimeType() {

    return $this->mimeType;

  }

  /**

   * {@inheritdoc}

   */

  public function getType() {

    return 'data';

  }

  /**

   * {@inheritdoc}

   */

  public function initDisplay(ViewExecutable $view, array &$display, array &$options = NULL) {

    parent::initDisplay($view, $display, $options);

    $this->setContentType('json');

    $this->setMimeType($this->view->getRequest()

      ->getMimeType($this->contentType));

  }

  /**

   * {@inheritdoc}

   */

  public function optionsSummary(&$categories, &$options) {

    parent::optionsSummary($categories, $options);

    // Hide some settings, as they aren't useful for pure data output.

    unset($categories['page'], $categories['exposed'], $options['show_admin_links'], $options['analyze-theme']);

    $categories['path'] = [

      'title' => $this->t('Path settings'),

      'column' => 'second',

      'build' => [

        '#weight' => -10,

      ],

    ];

    $options['path']['category'] = 'path';

    $options['path']['title'] = $this->t('Path');

    // Remove css/exposed form settings, as they are not used for the data

    // display.

    unset($options['exposed_form'], $options['exposed_block'], $options['css_class']);

  }

  /**

   * {@inheritdoc}

   *

   * The DisplayPluginBase preview method assumes we will be returning a render

   * array. The data plugin will already return the serialized string.

   */

  public function preview() {

    return $this->view->render();

  }

  /**

   * {@inheritdoc}

   */

  public function render() {

    $build = [];

    $build['#markup'] = $this

      ->getRenderer()

      ->executeInRenderContext(

        new RenderContext(),

        function () {

          return $this->view->style_plugin->render();

        }

      );

    $this->view->element['#content_type'] = $this->getMimeType();

    $this->view->element['#cache_properties'][] = '#content_type';

    // Encode and wrap the output in a pre tag if this is for a live preview.    // Wrap the output in a pre tag if this is for a live preview.

    if (!empty($this->view->live_preview)) {

      $build['#prefix'] = '<pre>';

      $build['#plain_text'] = $build['#markup'];

      $build['#suffix'] = '</pre>';

      unset($build['#markup']);

    }

    else {

      // This display plugin is for returning non-HTML formats. However, we

      // still invoke the renderer to collect cacheability metadata. Because the

      // renderer is designed for HTML rendering, it filters #markup for XSS

      // unless it is already known to be safe, but that filter only works for

      // HTML. Therefore, we mark the contents as safe to bypass the filter. So

      // long as we are returning this in a non-HTML response,

      // this is safe, because an XSS attack only works when executed by an HTML

      // agent.

      // @todo Decide how to support non-HTML in the render API in

      //   https://www.drupal.org/node/2501313.

      $build['#markup'] = ViewsRenderPipelineMarkup::create($build['#markup']);

    }

    parent::applyDisplayCacheabilityMetadata($build);

    return $build;

  }

  /**

   * Sets the content type.

   *

   * @param string $content_type

   *   The content type machine name. E.g. 'json'.

   */

  public function setContentType($content_type) {

    $this->contentType = $content_type;

  }

  /**

   * Sets the request content type.

   *

   * @param string $mime_type

   *   The response mime type. E.g. 'application/json'.

   */

  public function setMimeType($mime_type) {

    $this->mimeType = $mime_type;

  }

class GeoJsonExport extends RestExport {

  /**

   * {@inheritdoc}

   */

  protected function defineOptions() {

    $options = parent::defineOptions();

    // Set the default style plugin to 'json'.

    // Set the default style plugin to 'geojson'.

    $options['style']['contains']['type']['default'] = 'geojson';

    $options['row']['contains']['type']['default'] = 'data_field';

    $options['defaults']['default']['style'] = FALSE;

    $options['defaults']['default']['row'] = FALSE;

    // Remove css/exposed form settings, as they are not used for the data

    // display.

    unset(

      $options['exposed_form'],

      $options['exposed_block'],

      $options['css_class']

    );

    return $options;

  }

}