public function onStart($text)
    {
        // process of smileys and other special characters
        if ($this->getParam('convertSmileys'))
            $text = Smiley::convertSmileys($text);
        if ($this->getParam('convertSymbols'))
            $text = Smiley::convertSymbols($text);

        // if a specific pre-parse function was defined, it is called
        /** @var callable $func */
        $func = $this->getParam('preParseFunction');
        if (isset($func))
            $text = $func($text);
        return ($text);
    }