Question

I’m developing a website, but stuck at some point, where i needed to detect outgoing links on my website, and either forbid the links, or accept that, i don’t know how facebook is doing this, but they can do it through facebook.com/l.php that if the link is marked spam, users will get notified about it.

I don’t know if that’s a php or htaccess, it worked in php using the DOMDOCUMENT, but it’s not a real solution for this.

Answer 1

I’m not 100% sure how Facebook is implementing it, but what I would recommend is to use JQuery (or another javascript library) to rewrite all external links to a validating PHP script (e.g. Facebook’s l.php script), w/ the intended url getting passed as a GET parameter.

Using JQuery, it might look like:

$('a[href]').each(function(){
  var safe_href = 'http://yourdomain.com/yourscript.php?url='+$(this).attr('href');
  $(this).attr('href', safe_href);
});

You can can then do a database lookup in yourscript.php based on the variable $_GET['url'], and redirect to that url if it’s safe or display a message if it isn’t.