ContactFormAccessControlHandler.php

<?php

namespace Drupal\contact;

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

/**
 * Defines the access control handler for the contact form entity type.
 *
 * @see \Drupal\contact\Entity\ContactForm.
 */
class ContactFormAccessControlHandler extends EntityAccessControlHandler {
    
    /**
     * {@inheritdoc}
     */
    protected function checkAccess(EntityInterface $entity, $operation, AccountInterface $account) {
        if ($operation == 'view') {
            // Do not allow access personal form via site-wide route.
            return AccessResult::allowedIfHasPermission($account, 'access site-wide contact form')->andIf(AccessResult::allowedIf($entity->id() !== 'personal'));
        }
        elseif ($operation == 'delete' || $operation == 'update') {
            // Do not allow the 'personal' form to be deleted, as it's used for
            // the personal contact form.
            return AccessResult::allowedIfHasPermission($account, 'administer contact forms')->andIf(AccessResult::allowedIf($entity->id() !== 'personal'));
        }
        return parent::checkAccess($entity, $operation, $account);
    }

}