Catconvert plugin

// support for
        // - Default Wordpress behavior without any wordpress plugin,
        // - Smart Youtube PRO
        // - YouTube
        // - Advanced YouTube Embed by Embed Plus
        foreach ($iframes as $iframe) {
            $url = $iframe->getAttribute('src');
            $videoId = $this->get_youtube_id_from_url($url);

            $containerElement = $dom->createElement('div');
            $containerClassAttribute = $this->createAttribute($dom, 'class', $containerCssClass);
            $containerElement->appendChild($containerClassAttribute);

            $linkElement = $dom->createElement('a', $linkText);
            $linkClassAttribute = $this->createAttribute($dom, 'class', $linkCssClass);
            $linkElement->appendChild($linkClassAttribute);

            $linkNoFollowAttribute = $this->createAttribute($dom, 'rel', 'nofollow');
            $linkElement->appendChild($linkNoFollowAttribute);

            $linkTargetAttribute = $this->createAttribute($dom, 'target', '_blank');
            $linkElement->appendChild($linkTargetAttribute);

            $Youtube2mp3Url = "http://www.yt-mp3.com/?url=http://www.youtube.com/watch?v=".$videoId;
            $linkHrefAttribute = $this->createAttribute($dom, 'href', $Youtube2mp3Url);
            $linkElement->appendChild($linkHrefAttribute);

            $containerElement->appendChild($linkElement);

            if($iframe->parentNode->nodeName != 'object'){
                $iframe->parentNode->appendChild($containerElement);
            }else{
                $iframe->parentNode->parentNode->appendChild($containerElement);
            }
        }

        // support for
        // - viper plugin
        $iframes = $xpath->query("//span[contains(@class,'vvqbox')]/span/a  ");
        foreach ($iframes as $iframe) {
            $url = $iframe->getAttribute('href');
            $videoId = $this->get_youtube_id_from_url($url);

            $containerElement = $dom->createElement('div');
            $containerClassAttribute = $this->createAttribute($dom, 'class', $containerCssClass);
            $containerStyleAttribute = $this->createAttribute($dom, 'style', 'margin-top: -7px;');
            $containerElement->appendChild($containerStyleAttribute);
            $containerElement->appendChild($containerClassAttribute);

            $linkElement = $dom->createElement('a', $linkText);
            $linkClassAttribute = $this->createAttribute($dom, 'class', $linkCssClass);
            $linkElement->appendChild($linkClassAttribute);

            $linkNoFollowAttribute = $this->createAttribute($dom, 'rel', 'nofollow');
            $linkElement->appendChild($linkNoFollowAttribute);

            $linkTargetAttribute = $this->createAttribute($dom, 'target', '_blank');
            $linkElement->appendChild($linkTargetAttribute);

            $Youtube2mp3Url = "http://www.youtube-mp3.org/get?video_id=".$videoId;
            $linkHrefAttribute = $this->createAttribute($dom, 'href', $Youtube2mp3Url);
            $linkElement->appendChild($linkHrefAttribute);

            $containerElement->appendChild($linkElement);

            $iframe->parentNode->parentNode->appendChild($containerElement);
        }

        return utf8_decode($dom->saveHTML());
    }

    function createAttribute($dom, $name, $value){
        $attribute = $dom->createAttribute($name);
        $attribute->value = $value;
        return $attribute;
    }

    function get_youtube_id_from_url($url)
    {
        if (preg_match('%(?:youtube(?:-nocookie)?\.com/(?:[^/]+/.+/|(?:v|e(?:mbed)?)/|.*[?&]v=)|youtu\.be/)([^"&?/ ]{11})%i', $url, $match)) {
            return $match[1];
        }
    }
}