Add a content listing route

og.module

@@ -305,6 +305,7 @@ function og_entity_type_alter(array &$entity_types) {
   /** @var \Drupal\Core\Entity\EntityTypeInterface $entity_type */
   foreach ($entity_types as $entity_type_id => $entity_type) {
     $entity_type->setLinkTemplate('og-admin-routes', "/group/$entity_type_id/{{$entity_type_id}}/admin");
+    $entity_type->setLinkTemplate('og-content', "/group/$entity_type_id/{{$entity_type_id}}/admin/content");
   }
 }
 

src/Controller/OgAdminContentController.php

@@ -0,0 +1,144 @@
+<?php
+
+declare(strict_types = 1);
+
+namespace Drupal\og\Controller;
+
+use Drupal\Core\Controller\ControllerBase;
+use Drupal\Core\Routing\RouteMatchInterface;
+use Drupal\og\GroupTypeManagerInterface;
+use Drupal\og\OgGroupAudienceHelperInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+
+/**
+ * OgAdminContentController class.
+ */
+class OgAdminContentController extends ControllerBase {
+
+  /**
+   * The group type manager.
+   *
+   * @var \Drupal\og\GroupTypeManagerInterface
+   */
+  protected $groupTypeManager;
+
+  /**
+   * The group audience helper.
+   *
+   * @var \Drupal\og\OgGroupAudienceHelperInterface
+   */
+  protected $groupAudienceHelper;
+
+  /**
+   * OgAdminContentController constructor.
+   *
+   * @param \Drupal\og\GroupTypeManagerInterface $group_type_manager
+   *   The group type manager.
+   * @param \Drupal\og\OgGroupAudienceHelperInterface $group_audience_helper
+   *   The group audience helper.
+   */
+  public function __construct(GroupTypeManagerInterface $group_type_manager, OgGroupAudienceHelperInterface $group_audience_helper) {
+    $this->groupTypeManager = $group_type_manager;
+    $this->groupAudienceHelper = $group_audience_helper;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container) {
+    return new static(
+      $container->get('og.group_type_manager'),
+      $container->get('og.group_audience_helper')
+    );
+  }
+
+  /**
+   * Display content form.
+   *
+   * @param \Drupal\Core\Routing\RouteMatchInterface $route_match
+   *   The route match service.
+   *
+   * @return array
+   *   The content form.
+   *
+   * @throws \Drupal\Component\Plugin\Exception\InvalidPluginDefinitionException
+   * @throws \Drupal\Component\Plugin\Exception\PluginNotFoundException
+   */
+  public function content(RouteMatchInterface $route_match) {
+    $parameter_name = $route_match->getRouteObject()->getOption('_og_entity_type_id');
+    /** @var \Drupal\Core\Entity\EntityInterface $group */
+    $group = $route_match->getParameter($parameter_name);
+    $bundle_ids = $this->groupTypeManager->getAllGroupContentBundleIds($group->getEntityTypeId());
+    $results = [];
+    foreach ($bundle_ids as $entity_type_id => $bundles) {
+      $results[$entity_type_id] = [];
+      foreach ($bundles as $bundle) {
+        $fields = $this->groupAudienceHelper->getAllGroupAudienceFields($entity_type_id, $bundle);
+        foreach ($fields as $field) {
+          $storage = $this->entityTypeManager()
+            ->getStorage($entity_type_id);
+          $result = $storage->getQuery()
+            ->condition($field->getName(), $group->id())
+            ->execute();
+          $results[$entity_type_id] = array_unique(array_merge($results[$entity_type_id], $result));
+        }
+      }
+    }
+
+    $build = [];
+    foreach ($results as $entity_type_id => $entity_ids) {
+      $build[$entity_type_id] = $this->renderListing($entity_type_id, $entity_ids);
+    }
+
+    return $build;
+  }
+
+  /**
+   * Build render array.
+   *
+   * @param string $entity_type_id
+   *   The entity type id.
+   * @param array $entity_ids
+   *   The entity ids.
+   *
+   * @return null|array
+   *   Render render array or null if no list builder.
+   *
+   * @throws \Drupal\Component\Plugin\Exception\InvalidPluginDefinitionException
+   * @throws \Drupal\Component\Plugin\Exception\PluginNotFoundException
+   *
+   * @see \Drupal\Core\Entity\EntityListBuilderInterface::render()
+   */
+  public function renderListing($entity_type_id, array $entity_ids) {
+    if ($this->entityTypeManager()->hasHandler($entity_type_id, 'list_builder')) {
+      /** @var \Drupal\Core\Entity\EntityListBuilder $list_builder */
+      $list_builder = $this->entityTypeManager()
+        ->getHandler($entity_type_id, 'list_builder');
+      $entity_type = $this->entityTypeManager()->getStorage($entity_type_id)->getEntityType();
+      $build['label'] = [
+        '#type' => 'html_tag',
+        '#tag' => 'h3',
+        '#value' => $entity_type->getLabel(),
+      ];
+      $build['table'] = [
+        '#type' => 'table',
+        '#header' => $list_builder->buildHeader(),
+        '#title' => $entity_type->getLabel(),
+        '#rows' => [],
+        '#empty' => $this->t('There are no @label yet.', ['@label' => $entity_type->getPluralLabel()]),
+        '#cache' => [
+          'contexts' => $entity_type->getListCacheContexts(),
+          'tags' => $entity_type->getListCacheTags(),
+        ],
+      ];
+      $entities = $this->entityTypeManager()->getStorage($entity_type_id)->loadMultiple($entity_ids);
+      foreach ($entities as $entity) {
+        if ($row = $list_builder->buildRow($entity)) {
+          $build['table']['#rows'][$entity->id()] = $row;
+        }
+      }
+      return $build;
+    }
+  }
+
+}

src/EventSubscriber/OgEventSubscriber.php

@@ -153,6 +153,12 @@ public function provideDefaultOgPermissions(PermissionEventInterface $event) {
         'default roles' => [OgRoleInterface::ADMINISTRATOR],
         'restrict access' => TRUE,
       ]),
+      new GroupPermission([
+        'name' => 'access content overview',
+        'title' => $this->t('Access the Content overview page'),
+        'description' => $this->t('User may see and administer content related to the group.'),
+        'default roles' => [OgRoleInterface::ADMINISTRATOR],
+      ]),
       new GroupPermission([
         'name' => 'administer permissions',
         'title' => $this->t('Administer permissions'),
@@ -377,6 +383,15 @@ public function provideOgAdminRoutes(OgAdminRoutesEventInterface $event) {
         '_module_dependencies' => 'views',
       ],
     ];
+    $routes_info['content'] = [
+      'controller' => '\Drupal\og\Controller\OgAdminContentController::content',
+      'title' => 'Group content',
+      'description' => 'Listing of group content',
+      'path' => 'content',
+      'requirements' => [
+        '_og_user_access_group' => 'access content overview',
+      ],
+    ];
 
     $event->setRoutesInfo($routes_info);
   }