UserPermissionsRoleSpecificForm.php

<?php

namespace Drupal\user\Form;

use Drupal\Core\Form\FormStateInterface;
use Drupal\user\RoleInterface;

/**
 * Provides the user permissions administration form for a specific role.
 *
 * @internal
 */
class UserPermissionsRoleSpecificForm extends UserPermissionsForm {
    
    /**
     * The specific role for this form.
     *
     * @var \Drupal\user\RoleInterface
     */
    protected $userRole;
    
    /**
     * {@inheritdoc}
     */
    protected function getRoles() {
        return [
            $this->userRole
                ->id() => $this->userRole,
        ];
    }
    
    /**
     * Builds the user permissions administration form for a specific role.
     *
     * @param array $form
     *   An associative array containing the structure of the form.
     * @param \Drupal\Core\Form\FormStateInterface $form_state
     *   The current state of the form.
     * @param \Drupal\user\RoleInterface|null $user_role
     *   (optional) The user role used for this form. Defaults to NULL.
     */
    public function buildForm(array $form, FormStateInterface $form_state, RoleInterface $user_role = NULL) {
        $this->userRole = $user_role;
        return parent::buildForm($form, $form_state);
    }

}