MicroFrameWork/kernel/modules/user/models/forms/CreateUserForm.php

<?php

namespace kernel\modules\user\models\forms;

use kernel\FormModel;

class CreateUserForm extends FormModel
{

    public function rules(): array
    {
        return [
            'username' => 'required|min-str-len:5|max-str-len:30',
            'password' => 'required|min-str-len:5|max-str-len:30',
            'email' => 'required|email'
        ];
    }

    public function rulesForUpdate(): array
    {
        return [
            'username' => 'required|min-str-len:5|max-str-len:30',
            'password' => '',
            'email' => 'required|email'
        ];
    }

}