Why am I not getting back any images here?_问答_开发者

Why am I not getting back any images here?

开发者 https://www.devze.com 2023-02-26 19:09 出处：网络

$url = \'http://www.w3schools.com/js/js_loop_for.asp\'; $html = @file_get_contents($url); $doc = new DOMDocument();

$url = 'http://www.w3schools.com/js/js_loop_for.asp';
$html = @file_get_contents($url);

$doc = new DOMDocument();
@$doc->loadHTML($html);
$xml = @simplexml_import_dom($doc);
$images = $xml->xpath('//img');

var_dump($images);
die();

Output is:

array(0) { }

However, in the page source I see this:

<img border="0" width="336" heig开发者_开发问答ht="69" src="/images/w3schoolslogo.gif" alt="W3Schools.com" style="margin-top:5px;" />

Edit: It appears $html's contents stop at the <body> tag for this page. Any idea why?

It appears $html's contents stop at the tag for this page. Any idea why?

Yes, you must provide this page with a valid user agent.

$url = 'http://www.w3schools.com/js/js_loop_for.asp';
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_USERAGENT, "MozillaXYZ/1.0");
curl_exec($ch);

outputs everything to the ending </html> including your requested <img border="0" width="336" height="69" src="/images/w3schoolslogo.gif" alt="W3Schools.com" style="margin-top:5px;" />

When a simple wget or curl without the user agent returns only up to the <body> tag.

$url = 'http://www.w3schools.com/js/js_loop_for.asp';
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_USERAGENT, "MozillaXYZ/1.0");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$html = curl_exec($ch);

$doc = new DOMDocument();
$doc->loadHTML($html);
$xml = simplexml_import_dom($doc);
$images = $xml->xpath('//img');

var_dump($images);
die();

EDIT: My first post stated that there was still an issue with xpath... I was just not doing my due diligence and the updated code above works great. I forgot to force curl to output to a string rather then print to the screen(as it does by default).

Why bring simplexml into the mix? You're already loading the HTML from w3fools into the DOM class, which has a perfectly good XPath query engine in it already.

[...snip...]
$doc->loadHTML($html);
$xpath = new DOMXPath($doc)
$images = $xpath->xpath('//img');
[...snip...]

The IMG tag is generated by javascript. If you'd downloaded this page via wget, you'd realize there is no IMG tag in the HTML.

Update #1

I believe it is because of user agent string. If I supply "Mozilla/5.0 (X11; Linux i686 on x86_64; rv:2.0) Gecko/20100101 Firefox/4.0" as user agent id, I get the page in whole.