How can I find out what Page has installed my Facebook App / which page is loading my app

Question

I have a canvas app (http://apps.facebook.com/myapp) and other pages (businesses, etc) can Add it to their page. Within my app, how can I know which page I\'m being called f

Answer 1

As documented in Facebook Page Tab Tutorial:

When a user navigates to the Facebook Page, they will see your Page Tab added in the next available tab position. Broadly, a Page Tab is loaded in exactly the same way as a Canvas Page. When a user selects your Page Tab, you will received the signed_request parameter with one additional parameter, page. This parameter contains a JSON object with an id (the page id of the current page), admin (if the user is a admin of the page), and liked (if the user has liked the page). As with a Canvas Page, you will not receive all the user information accessible to your app in the signed_request until the user authorizes your app.

So one way to capture the page id would be:

 'APP_ID',
  'secret' => 'APP_SECRET',
  'cookie' => true,
));
$signed_request = $facebook->getSignedRequest();
if( $page = $signed_request['page'] ) {
    echo $page['id'];
}
?>

OR a solution without the PHP-SDK: