}
        Category::exportAllCertificates($cat_id, $userList);
        break;
    case 'generate_all_certificates':
        $user_list = CourseManager::get_user_list_from_course_code(api_get_course_id(), api_get_session_id());
        if (!empty($user_list)) {
            foreach ($user_list as $user_info) {
                if ($user_info['status'] == INVITEE) {
                    continue;
                }
                Category::register_user_certificate($cat_id, $user_info['user_id']);
            }
        }
        break;
    case 'delete_all_certificates':
        Category::deleteAllCertificates($cat_id);
        break;
}
$course_code = api_get_course_id();
$interbreadcrumb[] = array('url' => Security::remove_XSS($_SESSION['gradebook_dest']) . '?', 'name' => get_lang('Gradebook'));
$interbreadcrumb[] = array('url' => '#', 'name' => get_lang('GradebookListOfStudentsCertificates'));
$this_section = SECTION_COURSES;
Display::display_header('');
if (isset($_GET['action']) && $_GET['action'] == 'delete') {
    $check = Security::check_token('get');
    if ($check) {
        $certificate = new Certificate($_GET['certificate_id']);
        $result = $certificate->delete(true);
        Security::clear_token();
        if ($result == true) {
            Display::display_confirmation_message(get_lang('CertificateRemoved'));