FBML Canvas Application Authentication - php

Question

I'm modifying an FBML canvas app to use the new PHP SDK and authentication instead of the old REST api.
Right now I'm attempting to use this snippet:
$me = null;
// Session based API call.
if ($session) {
try {
$uid = $facebook->getUser();
$me = $facebook->api('/me');
} catch (FacebookApiException $e) {
error_log($e);
}
}
// login or logout url will be needed depending on current user state.
if ($me) {
} else {
$loginUrl = $facebook->getLoginUrl(array('req_perms' => 'user_birthday, publish_stream, email'));
header('Location: '.$loginUrl);
}
However if I use the php header function for any URL that isn't relative, I get this error:
Application Temporarily Unavailable
The URL [https://www.facebook.com/login.php?.........] is not valid.
Sorry, the application you were using is experiencing a problem. Please try again later.
If I need to have authentication on my FBML canvas app using the latest PHP SDK, how do I properly redirect to the app login page that requests the extended permissions?

Answer 1

Looks like you cannot use a server side redirect (header()) to push user to the auth page. I'm using this at the moment:
function redirect($url)
{
echo '<script>top.location="' . $url . '";</script>';
//echo '<fb:redirect url="' . $url . '"></fb:redirect>';
//header("location:$url");
exit();
}