Why is this Xpath Query not working on the DOM of facebook application pages?_问答_开发者

Why is this Xpath Query not working on the DOM of facebook application pages?

开发者 https://www.devze.com 2023-02-14 10:05 出处：网络

I dont understand why my xpath query returns the correct href f开发者_开发知识库or the second url but not the first url. The HTML code looks the same. It contains the same kind of structure. But someh

$url = "http://apps.facebook.com/TexasHoldEmPoker/"; // this one does not work
//$url = "http://nu.nl"; // this one works

$response = wp_remote_get($url);
$data = $response['body'];
$dom = new DOMDocument();
libxml_use_internal_errors(true);
$dom->strictErrorChecking = false;
$href='';
if (!$dom->loadHTML($data))
{
    foreach (libxml_get_errors() as $error)
    {
    }
    libxml_clear_errors();
}
else
{
    $xpath = new DOMXPath($dom);
    $elements = $xpath->query("/html/head/link[@rel='shortcut icon']");

    if (!is_null($elements))
    {
        foreach ($elements as $element)
        {
            if ($element->getAttribute('href'))
            {
                $href = $element->getAttribute('href');
            }
        }
    }
}
echo $href;

So I know the code is working correct for "nu.nl" but somehow not for the facebook apps pages. I cant grasp why since the structure is the same.

p.s. : full code here: http://plugins.svn.wordpress.org/wp-favicons/trunk/plugins/sources/page.php

Take a look at $dom->saveXML() .

You'll see that the <link>-element is a child of body, not of head like expected.

So the xpath should be:

/html/body/link[@rel='shortcut icon']

//link[@rel='shortcut icon']

I guess the different markup is a result of the parser when trying to fix the illegal <noscript> inside the <head>(everything inside the head after and including this <noscript> has been moved to the <body>)