How to like / share URLs inside Facebook that contain get-parameters

Question

We are working on a facebook-app with lots of dynamic pages. As the app is embedded in a tab on a facebook page, the urls contain a get-parameter to address the correct tab/app. We want to implement like- and send-buttons for several pages within our app, but facebook seems to dump all get-parameters from urls within facebook. As the result all like- and send-buttons point to the facebook-page itself instead of the tab.

Does anybody now any workaround? We already tried redirects via an external sefor facebook urls only.rver but facebook seems to evaluate the links on click of the like-/send-button (and seems to follow all sort of redirects).

UPDATE:
Here is an example of a problematic url:
https://www.facebook.com/smartmobil.de?sk=app_171502639574871

UPDATE:
The problem seems to be independant of url get-parameters. It seems that the like-button does not work with any url starting with www.facebook.com

When used in a like-button everything behind the ? will be dumped. This seems to happen for facebook urls only.

Answer 1

Best workaround so far is to point your like buttons at external (non-facebook canvas) urls.

To make this work, you need to do some conditional redirecting to get the user back into your canvas URL. You can either use a client side javascript redirect:

<script>
  window.location = 'http://apps.facebook.com/yourcanvasname/foo/bar';
</script>

Or you can do a server side redirect based on the useragent string. Basically, if the useragent contains 'facebookexternalhit' then render a basic HTML page containing OG tags, if not, redirect to the canvas URL.

Doing this means the Facebook sharescraper/linter won't follow any redirects back to the canvas URL, but any user that arrives at your URL will get back to Canvas.

Answer 2

i'm too searching for a solution to control the custom page tab's content through a get parameter (app_data). I still don't have a solution but here at least the reason why all www.facebook.com links are srtiped out of get params. Here at bottom the developer explains why.