Convert a relative URL to an absolute URL with Simple HTML DOM?

Question

When I\'m scraping content from some pages, the script gives a relative URL. Is it possible to get a absolute URL with Simple HTML DOM?

Answer 1

I don’t think that the Simple HTML DOM Parser can do that.

But you can do that on your own. First you need to distinguish the base URI that is the URI of the document if not declared otherwise (see BASE element). Than get each URI reference and apply the algorithms to resolve a relative URI as described in RFC 3986 (there already are classes you can use for that like the PEAR package Net_URL2).

So, using these two classes, you could do something like this:

$uri = new Net_URL2('http://example.com/foo/bar'); // URI of the resource
$baseURI = $uri;
foreach ($html->find('base[href]') as $elem) {
    $baseURI = $uri->resolve($elem->href);
}

foreach ($html->find('*[src]') as $elem) {
    $elem->src = $baseURI->resolve($elem->src)->__toString();
}
foreach ($html->find('*[href]') as $elem) {
    if (strtoupper($elem->tag) === 'BASE') continue;
    $elem->href = $baseURI->resolve($elem->href)->__toString();
}
foreach ($html->find('form[action]') as $elem) {
    $elem->action = $baseURI->resolve($elem->action)->__toString();
}

Repeat the substitution for any other attribute containing a URI like background, cite, classid, codebase, data, longdesc, profile and usemap (see index of attributes in HTML 4.01).