reserve/src/ReserveCategoryHtmlRouteProvider.php

<?php

namespace Drupal\reserve;

use Drupal\Core\Entity\EntityTypeInterface;
use Drupal\Core\Entity\Routing\AdminHtmlRouteProvider;
use Symfony\Component\Routing\Route;

/**
 * Provides routes for reservation categories.
 *
 * @see Drupal\Core\Entity\Routing\AdminHtmlRouteProvider
 * @see Drupal\Core\Entity\Routing\DefaultHtmlRouteProvider
 */
class ReserveCategoryHtmlRouteProvider extends AdminHtmlRouteProvider {

  /**
   * {@inheritdoc}
   */
  public function getRoutes(EntityTypeInterface $entity_type) {
    $collection = parent::getRoutes($entity_type);

    $entity_type_id = $entity_type->id();

    if ($collection_route = $this->getCollectionRoute($entity_type)) {
      $collection->add("entity.{$entity_type_id}.collection", $collection_route);
    }

    if ($settings_form_route = $this->getSettingsFormRoute($entity_type)) {
      $collection->add("$entity_type_id.settings", $settings_form_route);
    }

    return $collection;
  }

  /**
   * Gets the collection route.
   *
   * @param \Drupal\Core\Entity\EntityTypeInterface $entity_type
   *   The entity type.
   *
   * @return \Symfony\Component\Routing\Route|null
   *   The generated route, if available.
   */
  protected function getCollectionRoute(EntityTypeInterface $entity_type) {
    if ($entity_type->hasLinkTemplate('collection') && $entity_type->hasListBuilderClass()) {
      $entity_type_id = $entity_type->id();
      $route = new Route($entity_type->getLinkTemplate('collection'));
      $route
        ->setDefaults([
          '_entity_list' => $entity_type_id,
          '_title' => "{$entity_type->getLabel()} list",
        ])
        ->setRequirement('_permission', 'access reservation category overview')
        ->setOption('_admin_route', TRUE);

      return $route;
    }
  }

  /**
   * Gets the settings form route.
   *
   * @param \Drupal\Core\Entity\EntityTypeInterface $entity_type
   *   The entity type.
   *
   * @return \Symfony\Component\Routing\Route|null
   *   The generated route, if available.
   */
  protected function getSettingsFormRoute(EntityTypeInterface $entity_type) {
    if (!$entity_type->getBundleEntityType()) {
      $route = new Route("/admin/structure/{$entity_type->id()}/settings");
      $route
        ->setDefaults([
          '_form' => 'Drupal\reserve\Form\ReserveCategorySettingsForm',
          '_title' => "{$entity_type->getLabel()} settings",
        ])
        ->setRequirement('_permission', $entity_type->getAdminPermission())
        ->setOption('_admin_route', TRUE);

      return $route;
    }
  }

}