How to detect the Facebook Like button and click the trigger button?

Question

Here is an example:

• http://www.facebook.com/UEvents?v=app_4949752878&ref=ts

These guys force people to click the Like button (in the first step) before allowing the user to upload the video in step 2.

Interestingly, the “Names” button was detected and the page refreshed to show a blurry image in step 2 so that the user can click to load.

And it seems like I remember that I click “Like” (when I reload the page), so the “Like” button is no longer displayed and it only shows step 2.

What is their trade trick?

Answer 1

When the Facebook tab is loaded, the fb_sig_is_fan parameter is passed when it indicates whether the current user viewing the tab is a fan. Pressing the “Like” button will reload the contents of the tab, as a result of which the updated fb_sig_is_fan file will be transferred so that the application can display another image.

Answer 2

In fact, information if the user is a fan of the page or does not exist in the signed request. Since you need to decode the signed request first, as it is here:

$signed_request = $_REQUEST["signed_request"]; list($encoded_sig, $payload) = explode('.', $signed_request, 2); $data = json_decode(base64_decode(strtr($payload, '-_', '+/')), true); 

And after this access page I liked the variable:

 $pageLiked = $data['page']['liked']; 

Now FB is on the path to obsolete FBML, so don't consider <fb:visible-to-connection> as something that works for a long base.

Answer 3

http://developers.facebook.com/docs/reference/javascript/FB.Event.subscribe/

 FB.Event.subscribe('edge.create', function(response) { // do something with response.session }); 

Answer 4

 <fb:visible-to-connection> put here code for users that like the page (no <fb:comments>) </fb:visible-to-connection> 

Answer 5

You can determine when the user clicks on the button using edge.create . Also, if the user already liked the page, it can be detected using the FQL Like table.