public function loadPOST()
    {
        $post = $_POST;

        $this->hook('loadPOST', [&$post]);
        $errors = [];

        foreach ($this->fields as $key => $field) {
            try {
                $value = isset($post[$key]) ? $post[$key] : null;

                // save field value only if field was editable in form at all
                if (!$field->readonly && !$field->disabled) {
                    $this->model[$key] = $this->app->ui_persistence->typecastLoadField($field->field, $value);
                }
            } catch (\atk4\core\Exception $e) {
                $errors[$key] = $e->getMessage();
            }
        }

        if ($errors) {
            throw new \atk4\data\ValidationException($errors);
        }
    }