public static function getTemplateQti(){
        if(empty(static::$qtiTagName)){
            throw new QtiModelException('The element has no tag name defined : '.get_called_class());
        }
        $template = static::getTemplatePath().'/qti.'.static::$qtiTagName.'.tpl.php';
        if(!file_exists($template)){
            $template = static::getTemplatePath().'/qti.element.tpl.php';
        }

        return $template;
    }