RoleAccessCheck.php

<?php

namespace Drupal\user\Access;

use Drupal\Core\Access\AccessResult;
use Drupal\Core\Routing\Access\AccessInterface;
use Drupal\Core\Session\AccountInterface;
use Symfony\Component\Routing\Route;

/**
 * Determines access to routes based on roles.
 *
 * You can specify the '_role' key on route requirements. If you specify a
 * single role, users with that role with have access. If you specify multiple
 * ones you can conjunct them with AND by using a "," and with OR by using "+".
 */
class RoleAccessCheck implements AccessInterface {
    
    /**
     * Checks access.
     *
     * @param \Symfony\Component\Routing\Route $route
     *   The route to check against.
     * @param \Drupal\Core\Session\AccountInterface $account
     *   The currently logged in account.
     *
     * @return \Drupal\Core\Access\AccessResultInterface
     *   The access result.
     */
    public function access(Route $route, AccountInterface $account) {
        // Requirements just allow strings, so this might be a comma separated list.
        $rid_string = $route->getRequirement('_role');
        $explode_and = array_filter(array_map('trim', explode(',', $rid_string)));
        if (count($explode_and) > 1) {
            $diff = array_diff($explode_and, $account->getRoles());
            if (empty($diff)) {
                return AccessResult::allowed()->addCacheContexts([
                    'user.roles',
                ]);
            }
        }
        else {
            $explode_or = array_filter(array_map('trim', explode('+', $rid_string)));
            $intersection = array_intersect($explode_or, $account->getRoles());
            if (!empty($intersection)) {
                return AccessResult::allowed()->addCacheContexts([
                    'user.roles',
                ]);
            }
        }
        // If there is no allowed role, give other access checks a chance.
        return AccessResult::neutral()->addCacheContexts([
            'user.roles',
        ]);
    }

}