yf_dynamic_validate user module

    public function ajax_validate()
    {
        $error_msg = null;
        no_graphics(true);
        header('X-Robots-Tag: noindex, nofollow, noarchive, nosnippet');

        $allowed_params = $this->_parent->AJAX_VALIDATE_ALLOWED;

        $rules = [];
        $errors = [];
        if (isset($_POST['rules']) && is_array($_POST['rules'] ?? null)) {
            $rules = ($_POST['rules'] ?? null);
        } elseif (isset($_GET['rules']) && is_array($_GET['rules'] ?? null)) {
            $rules = ($_GET['rules'] ?? null);
        } else {
            $rules[] = [
                'func' => preg_replace('~[^a-z0-9_]+~ims', '', (isset($_POST['func']) ? ($_POST['func'] ?? null) : (isset($_GET['func']) ? ($_GET['func'] ?? null) : ($_GET['id'] ?? null)))),
                'data' => isset($_POST['data']) ? ($_POST['data'] ?? null) : ($_GET['data'] ?? null),
                'param' => isset($_POST['param']) ? ($_POST['param'] ?? null) : ($_GET['param'] ?? null),
                'field' => isset($_POST['field']) ? ($_POST['field'] ?? null) : ($_GET['field'] ?? null),
            ];
        }
        $class_validate = _class('validate');
        $is_valid = false;
        $error_msg = null;
        foreach ((array) $rules as $rule) {
            if ($rule['data'] === null) {
                $errors[] = 'empty data';
            }
            if (strlen($rule['param'])) {
                $not_allowed_param = true;
                if (in_array($rule['param'], $allowed_params)) {
                    $not_allowed_param = false;
                } else {
                    foreach ((array) $allowed_params as $aparam) {
                        // is_unique_without[user.login.1]
                        if ($rule['param'] && strpos($rule['param'], $aparam . '.') === 0) {
                            $not_allowed_param = false;
                            break;
                        }
                    }
                }
                if ($not_allowed_param) {
                    $errors[] = 'not allowed param';
                }
            }
            if ( ! preg_match('~^[a-z][a-z0-9_]+$~ims', $rule['func'])) {
                $errors[] = 'wrong func name';
            } elseif ( ! method_exists($class_validate, $rule['func'])) {
                $errors[] = 'no such func';
            }
            if ($errors) {
                break;
            }
            if ($rule['param'] == 'user.email') {
                $email_valid = $class_validate->valid_email($rule['data'], [], [], $error_msg);
                if ( ! $email_valid) {
                    break;
                }
            }
            $fname = (string) $rule['func'];
            $is_valid = $class_validate->$fname($rule['data'], ['param' => $rule['param']], [], $error_msg);
            if ( ! $is_valid) {
                if ( ! $error_msg) {
                    $error_msg = t('form_validate_' . $rule['func'], ['%field' => $rule['field'], '%param' => $rule['param']]);
                }
                break;
            }
        }
        if ($errors) {
            $out = ['error' => $errors];
        } else {
            if ($is_valid) {
                $out = ['ok' => 1];
            } else {
                $out = ['ko' => 1];
            }
        }
        if ($error_msg) {
            $out['error_msg'] = $error_msg;
        }
        $is_ajax = conf('IS_AJAX');
        if ($is_ajax) {
            header('Content-type: application/json');
        }
        echo json_encode($out);
        if ($is_ajax) {
            exit;
        }
    }

    public function __call($name, $arguments)
    {
        trigger_error(__CLASS__ . ': No method ' . $name, E_USER_WARNING);
        return false;
    }

    public function __construct()
    {
        $this->_parent = module('dynamic');
    }