CMarkdownParser

public function _doCodeBlocks_callback($matches)
{
    $codeblock = $this->outdent($matches[1]);
    if(($codeblock = $this->highlightCodeBlock($codeblock)) !== null)
        return "\n\n".$this->hashBlock($codeblock)."\n\n";
    else
        return parent::_doCodeBlocks_callback($matches);
}

public function _doFencedCodeBlocks_callback($matches)
{
    return "\n\n".$this->hashBlock($this->highlightCodeBlock($matches[2]))."\n\n";
}

protected function createHighLighter($options)
{
    if(!class_exists('Text_Highlighter', false))
    {
        require_once(Yii::getPathOfAlias('system.vendors.TextHighlighter.Text.Highlighter').'.php');
        require_once(Yii::getPathOfAlias('system.vendors.TextHighlighter.Text.Highlighter.Renderer.Html').'.php');
    }
    $lang = current(preg_split('/\s+/', substr(substr($options,1), 0,-1),2));
    $highlighter = Text_Highlighter::factory($lang);
    if($highlighter)
        $highlighter->setRenderer(new Text_Highlighter_Renderer_Html($this->getHiglightConfig($options)));
    return $highlighter;
}

public function getDefaultCssFile()
{
    return Yii::getPathOfAlias('system.vendors.TextHighlighter.highlight').'.css';
}

protected function getHighlightTag($codeblock)
{
    $str = trim(current(preg_split("/\r|\n/", $codeblock,2)));
    if(strlen($str) > 2 && $str[0] === '[' && $str[strlen($str)-1] === ']')
        return $str;
}

public function getHiglightConfig($options)
{
    $config['use_language'] = true;
    if( $this->getInlineOption('showLineNumbers', $options, false) )
        $config['numbers'] = HL_NUMBERS_LI;
    $config['tabsize'] = $this->getInlineOption('tabSize', $options, 4);
    return $config;
}

protected function getInlineOption($name, $str, $defaultValue)
{
    if(preg_match('/'.$name.'(\s*=\s*(\d+))?/i', $str, $v) && count($v) > 2)
        return $v[2];
    else
        return $defaultValue;
}

protected function highlightCodeBlock($codeblock)
{
    if(($tag=$this->getHighlightTag($codeblock))!==null && ($highlighter=$this->createHighLighter($tag)))
    {
        $codeblock = preg_replace('/\A\n+|\n+\z/', '', $codeblock);
        $tagLen = strpos($codeblock, $tag)+strlen($tag);
        $codeblock = ltrim(substr($codeblock, $tagLen));
        $output=preg_replace('/<span\s+[^>]*>(\s*)<\/span>/', '\1', $highlighter->highlight($codeblock));
        return "<div class=\"{$this->highlightCssClass}\">".$output."</div>";
    }
    else
        return "<pre>".CHtml::encode($codeblock)."</pre>";
}

public function safeTransform($content)
{
    $content=$this->transform($content);
    $purifier=new HTMLPurifier($this->purifierOptions);
    $purifier->config->set('Cache.SerializerPath',Yii::app()->getRuntimePath());
    return $purifier->purify($content);
}