crm_core-8.x-3.x-dev/modules/crm_core_activity/src/ActivityTypeAccessControlHandler.php

<?php

namespace Drupal\crm_core_activity;

use Drupal\Core\Access\AccessResult;
use Drupal\Core\Entity\EntityAccessControlHandler;
use Drupal\Core\Entity\EntityInterface;
use Drupal\Core\Session\AccountInterface;

/**
 * Activity Type Access Control Handler.
 */
class ActivityTypeAccessControlHandler extends EntityAccessControlHandler {

  /**
   * {@inheritdoc}
   */
  protected function checkAccess(
    EntityInterface $entity,
    $operation,
    AccountInterface $account,
  ) {

    // First check drupal permission.
    if (parent::checkAccess($entity, $operation, $account)->isForbidden()) {
      return AccessResult::forbidden();
    }

    switch ($operation) {
      case 'enable':
        // Only disabled activity type can be enabled.
        return AccessResult::allowedIf(!$entity->status());

      case 'disable':
        return AccessResult::allowedIf($entity->status());

      case 'delete':
        // If the activity instance of this activity type exist, you can't
        // delete it.
        $count = \Drupal::entityQuery('crm_core_activity')
          ->condition('type', $entity->id())
          ->accessCheck(TRUE)
          ->count()
          ->execute();

        return AccessResult::allowedIf($count == 0);

      case 'view':
      case 'update':
        return AccessResult::allowed();

      default:
        return AccessResult::neutral();
    }
  }

}