使用XPath和PHP刮取HTML页面

Question

我正在尝试使用此PHP代码来抓取HTML页面

<?php
    ini_set('display_errors', 1);

    $url = 'http://www.cittadellasalute.to.it/index.php?option=com_content&view=article&id=6786:situazione-pazienti-in-pronto-soccorso&catid=165:pronto-soccorso&Itemid=372';


    //#Set CURL parameters: pay attention to the PROXY config !!!!
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_AUTOREFERER, TRUE);
    curl_setopt($ch, CURLOPT_HEADER, 0);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_FOLLOWLOCATION, TRUE);
    curl_setopt($ch, CURLOPT_PROXY, '');
    $data = curl_exec($ch);
    curl_close($ch);

    $dom = new DOMDocument();
    @$dom->loadHTML($data);

    $xpath = new DOMXPath($dom);

    $greenWaitingNumber = $xpath->query('/html/body/div/div/div[4]/div[3]/section/p');


    foreach( $greenWaitingNumber as $node )
    {
      echo "Number first green line: " .$node->nodeValue;
      echo '<br>';
      echo '<br>';
    }


?>

一切正常（没有错误，在我的浏览器控制台中我可以看到'200'作为返回代码...），但我的HTML页面中没有打印....

问题可能是关于xpath / html / body / div / div / div [4] / div [3] / section / p引用源HTML页面中的第一个绿线，但这是我的Firefox Firebug告诉我该页面部分......

建议/示例？

!!!更新!!!!

正如Santosh Sapkota在回复中建议的那样，第一个问题是绿色框内的文字是从iFrame加载的...我在IFrame广告中看到了HTML页面的网址所以我试过在我的代码中使用这个，现在是......

<?php
    ini_set('display_errors', 1);

    $url = 'http://listeps.cittadellasalute.to.it/?id=01090101';


    //#Set CURL parameters: pay attention to the PROXY config !!!!
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_AUTOREFERER, TRUE);
    curl_setopt($ch, CURLOPT_HEADER, 0);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_FOLLOWLOCATION, TRUE);
    curl_setopt($ch, CURLOPT_PROXY, '');
    $data = curl_exec($ch);
    curl_close($ch);

    $dom = new DOMDocument();
    @$dom->loadHTML($data);

    $xpath = new DOMXPath($dom);

    $greenWaitingNumber = $xpath->query('/html/body/div/div/div[4]/div[3]/section/p');


    foreach( $greenWaitingNumber as $node )
    {
      echo "Number first green line: " .$node->nodeValue;
      echo '<br>';
      echo '<br>';
    }


?>

但遗憾的是，我的输出HTML页面中仍未打印任何内容....

其他建议/例子？