EWPP-452: Add RSS feeds for nodes based on list page metadata.

oe_list_pages.module

@@ -29,6 +29,18 @@ function oe_list_pages_theme($existing, $type, $theme, $path) {
         'label' => NULL,
       ],
     ],
+    'oe_list_pages_rss' => [
+      'variables' => [
+        'title' => '',
+        'link' => '',
+        'description' => '',
+        'language' => '',
+        'copyright' => '',
+        'image' => [],
+        'channel_elements' => [],
+        'items' => [],
+      ],
+    ],
   ];
 }
 

oe_list_pages.routing.yml

@@ -0,0 +1,7 @@
+entity.node.list_page_rss:
+  path: '/node/{node}/rss'
+  defaults:
+    _controller: '\Drupal\oe_list_pages\Controller\ListPageRssController::build'
+  requirements:
+    _custom_access: '\Drupal\oe_list_pages\Controller\ListPageRssController::checkAccess'
+    _entity_access: 'node.view'

src/Controller/ListPageRssController.php

@@ -0,0 +1,278 @@
+<?php
+
+declare(strict_types = 1);
+
+namespace Drupal\oe_list_pages\Controller;
+
+use Drupal\Component\Render\FormattableMarkup;
+use Drupal\Core\Access\AccessResult;
+use Drupal\Core\Access\AccessResultInterface;
+use Drupal\Core\Cache\CacheableMetadata;
+use Drupal\Core\Cache\CacheableResponse;
+use Drupal\Core\Config\ConfigFactoryInterface;
+use Drupal\Core\Controller\ControllerBase;
+use Drupal\Core\Entity\EntityTypeManagerInterface;
+use Drupal\Core\Render\Element;
+use Drupal\Core\Render\RendererInterface;
+use Drupal\Core\Theme\ThemeManagerInterface;
+use Drupal\Core\Url;
+use Drupal\emr\Entity\EntityMetaInterface;
+use Drupal\node\NodeInterface;
+use Drupal\oe_list_pages\ListBuilderInterface;
+use Drupal\oe_list_pages\ListPageRssAlterEvent;
+use Drupal\oe_list_pages\ListPageEvents;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+use Symfony\Component\EventDispatcher\EventDispatcherInterface;
+use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
+
+/**
+ * Controller for the List pages RSS feed routes.
+ */
+class ListPageRssController extends ControllerBase {
+
+  /**
+   * The config factory.
+   *
+   * @var \Drupal\Core\Config\ConfigFactoryInterface
+   */
+  protected $configFactory;
+
+  /**
+   * The entity type manager.
+   *
+   * @var \Drupal\Core\Entity\EntityTypeManagerInterface
+   */
+  protected $entityTypeManager;
+
+  /**
+   * The event dispatcher.
+   *
+   * @var \Symfony\Component\EventDispatcher\EventDispatcherInterface
+   */
+  protected $eventDispatcher;
+
+  /**
+   * The list builder.
+   *
+   * @var \Drupal\oe_list_pages\ListBuilderInterface
+   */
+  protected $listBuilder;
+
+  /**
+   * The renderer service.
+   *
+   * @var \Drupal\Core\Render\RendererInterface
+   */
+  protected $renderer;
+
+  /**
+   * The theme manager.
+   *
+   * @var \Drupal\Core\Theme\ThemeManagerInterface
+   */
+  protected $themeManager;
+
+  /**
+   * ListPageRssController constructor.
+   *
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
+   *   The entity type manager.
+   * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
+   *   The entity type manager.
+   * @param \Symfony\Component\EventDispatcher\EventDispatcherInterface $event_dispatcher
+   *   The event dispatcher.
+   * @param \Drupal\oe_list_pages\ListBuilderInterface $list_builder
+   *   The list builder.
+   * @param \Drupal\Core\Render\RendererInterface $renderer
+   *   The event dispatcher.
+   * @param \Drupal\Core\Theme\ThemeManagerInterface $theme_manager
+   *   The theme manager.
+   */
+  public function __construct(ConfigFactoryInterface $config_factory, EntityTypeManagerInterface $entity_type_manager, EventDispatcherInterface $event_dispatcher, ListBuilderInterface $list_builder, RendererInterface $renderer, ThemeManagerInterface $theme_manager) {
+    $this->configFactory = $config_factory;
+    $this->entityTypeManager = $entity_type_manager;
+    $this->eventDispatcher = $event_dispatcher;
+    $this->listBuilder = $list_builder;
+    $this->renderer = $renderer;
+    $this->themeManager = $theme_manager;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container): ListPageRssController {
+    return new static(
+      $container->get('config.factory'),
+      $container->get('entity_type.manager'),
+      $container->get('event_dispatcher'),
+      $container->get('oe_list_pages.builder'),
+      $container->get('renderer'),
+      $container->get('theme.manager')
+    );
+  }
+
+  /**
+   * Render the RSS feed of a list page result.
+   *
+   * @param \Drupal\node\NodeInterface $node
+   *   The list page node.
+   *
+   * @return \Drupal\Core\Cache\CacheableResponse
+   *   The RSS feed response.
+   */
+  public function build(NodeInterface $node): CacheableResponse {
+    // Build the render array for the RSS feed.
+    $cache_metadata = CacheableMetadata::createFromObject($node);
+    $default_title = $this->getChannelTitle($node, $cache_metadata);
+    $default_link = $node->toUrl('canonical', ['absolute' => TRUE])->toString(TRUE);
+    $build = [
+      '#theme' => 'oe_list_pages_rss',
+      '#title' => $default_title,
+      '#link' => $default_link->getGeneratedUrl(),
+      '#description' => $this->getChannelDescription($node, $cache_metadata),
+      '#language' => $node->language()->getId(),
+      '#copyright' => $this->getChannelCopyright(),
+      '#image' => $this->getChannelImage($cache_metadata),
+      '#channel_elements' => [],
+      '#items' => $this->getItemList($node),
+    ];
+    $cache_metadata->addCacheableDependency($default_link);
+    $cache_metadata->applyTo($build);
+
+    // Dispatch event to allow modules to alter the build before being rendered.
+    $event = new ListPageRssAlterEvent($build, $node);
+    $this->eventDispatcher->dispatch(ListPageEvents::ALTER_RSS_BUILD, $event);
+    $build = $event->getBuild();
+
+    // Create the response and add the xml type header.
+    $response = new CacheableResponse('', 200);
+    $response->headers->set('Content-Type', 'application/rss+xml; charset=utf-8');
+
+    // Render the list and add it to the response.
+    $output = (string) $this->renderer->renderRoot($build);
+    if (empty($output)) {
+      throw new NotFoundHttpException();
+    }
+    $response->setContent($output);
+    $response->addCacheableDependency($cache_metadata);
+
+    return $response;
+  }
+
+  /**
+   * Returns a list of items to be rendered.
+   *
+   * @param \Drupal\node\NodeInterface $node
+   *   The node containing the list.
+   *
+   * @return array
+   *   Array of items to be rendered.
+   */
+  protected function getItemList(NodeInterface $node): array {
+    return [];
+  }
+
+  /**
+   * Asserts whether we can access the RSS route for a given node.
+   *
+   * @param \Drupal\node\NodeInterface $node
+   *   The node being checked.
+   *
+   * @return \Drupal\Core\Access\AccessResultInterface
+   *   The access result.
+   */
+  public function checkAccess(NodeInterface $node): AccessResultInterface {
+    $entity_meta = $node->get('emr_entity_metas')->getEntityMeta('oe_list_page');
+    if ($entity_meta instanceof EntityMetaInterface && !$entity_meta->isNew()) {
+      return AccessResult::allowed()->addCacheableDependency($node);
+    }
+
+    return AccessResult::forbidden($this->t('Node type does not have List Page meta configured.'))->addCacheableDependency($node);
+  }
+
+  /**
+   * Get the channel title.
+   *
+   * @param \Drupal\node\NodeInterface $node
+   *   The node being rendered.
+   * @param \Drupal\Core\Cache\CacheableMetadata $cache_metadata
+   *   The current cache metadata.
+   *
+   * @return string
+   *   The channel title.
+   */
+  protected function getChannelTitle(NodeInterface $node, CacheableMetadata $cache_metadata): string {
+    $site_config = $this->configFactory->get('system.site');
+    $cache_metadata->addCacheableDependency($site_config);
+    $site_name = $site_config->get('name');
+    return $site_name . ' | ' . $node->label();
+  }
+
+  /**
+   * Get the channel image array.
+   *
+   * @param \Drupal\Core\Cache\CacheableMetadata $cache_metadata
+   *   The current cache metadata.
+   *
+   * @return array
+   *   The image information array.
+   */
+  protected function getChannelImage(CacheableMetadata $cache_metadata): array {
+    $title = $this->t('@title logo', ['@title' => 'European Commission']);
+    // Get the logo location.
+    $theme = $this->themeManager->getActiveTheme();
+    $site_url = Url::fromRoute('<front>', [], ['absolute' => TRUE])->toString(TRUE);
+    $cache_metadata->addCacheableDependency($site_url);
+
+    return [
+      'url' => file_create_url($theme->getLogo()),
+      'title' => $title,
+      'link' => $site_url->getGeneratedUrl(),
+    ];
+  }
+
+  /**
+   * Get the channel description.
+   *
+   * The default channel description shows a complete list of selected
+   * filter labels and values.
+   *
+   * @param \Drupal\node\NodeInterface $node
+   *   The node being rendered.
+   * @param \Drupal\Core\Cache\CacheableMetadata $cache_metadata
+   *   The current cache metadata.
+   *
+   * @return string
+   *   The default description.
+   */
+  protected function getChannelDescription(NodeInterface $node, CacheableMetadata $cache_metadata): string {
+    $selected_filter_information = $this->listBuilder->buildSelectedFilters($node);
+    $filter_cache = CacheableMetadata::createFromRenderArray($selected_filter_information);
+    $cache_metadata->addCacheableDependency($filter_cache);
+    // Extract the selected filter information.
+    $selected_filters = [];
+    foreach (Element::children($selected_filter_information) as $child) {
+      $filter_information = $selected_filter_information[$child];
+      $filter_values = [];
+      if (!isset($filter_information['#items'])) {
+        continue;
+      }
+      foreach ($filter_information['#items'] as $filter_value_information) {
+        $filter_values[] = $filter_value_information['label'];
+      }
+      $selected_filters[] = $filter_information['#label'] . ': ' . implode(', ', $filter_values);
+    }
+    return implode(' | ', $selected_filters);
+  }
+
+  /**
+   * Get the channel copyright value.
+   *
+   * @return \Drupal\Component\Render\FormattableMarkup
+   *   The default copyright value.
+   */
+  protected function getChannelCopyright(): FormattableMarkup {
+    return new FormattableMarkup('© @copyright_name, 1995-@enddate', ['@copyright_name' => $this->t('European Union'), '@enddate' => date('Y')]);
+  }
+
+}

src/ListPageEvents.php

@@ -23,4 +23,11 @@ final class ListPageEvents {
    */
   const ALTER_BUNDLES = 'oe_list_pages.bundles_alter';
 
+  /**
+   * Event fired when the RSS build before its rendered.
+   *
+   * @var string
+   */
+  const ALTER_RSS_BUILD = "oe_list_pages.rss_build_alter";
+
 }

src/ListPageRssAlterEvent.php

@@ -0,0 +1,72 @@
+<?php
+
+declare(strict_types = 1);
+
+namespace Drupal\oe_list_pages;
+
+use Drupal\node\NodeInterface;
+use Symfony\Component\EventDispatcher\Event;
+
+/**
+ * Event thrown in order to alter the RSS build before its rendered.
+ */
+class ListPageRssAlterEvent extends Event {
+
+  /**
+   * The render array for the list page RSS list.
+   *
+   * @var array
+   */
+  protected $build;
+
+  /**
+   * The node being rendered.
+   *
+   * @var \Drupal\node\NodeInterface
+   */
+  protected $node;
+
+  /**
+   * Constructs the object.
+   *
+   * @param array $build
+   *   The render array for the list page RSS list.
+   * @param \Drupal\node\NodeInterface $node
+   *   The node being rendered.
+   */
+  public function __construct(array $build, NodeInterface $node) {
+    $this->build = $build;
+    $this->node = $node;
+  }
+
+  /**
+   * Returns the build.
+   *
+   * @return array
+   *   The current build.
+   */
+  public function getBuild(): array {
+    return $this->build;
+  }
+
+  /**
+   * Sets the build.
+   *
+   * @param array $build
+   *   The modified build.
+   */
+  public function setBuild(array $build): void {
+    $this->build = $build;
+  }
+
+  /**
+   * Returns the list page.
+   *
+   * @return \Drupal\node\NodeInterface
+   *   The list page being processed.
+   */
+  public function getNode(): NodeInterface {
+    return $this->node;
+  }
+
+}