Facebook PHP SDK 3.1.1无限循环

Question

i have the following code:

$facebook = new Facebook(array('appId' => $FB_APP_ID,
                             'secret' => $FB_APP_KEY,
                             'cookie' => true));
$fb_sess = $facebook->getUser();

if (empty($fb_sess)) {

  $url = $facebook->getLoginUrl(array('response_type'=>'token',
                                        'scope' => 'email'));
  header("Location: $url");

}

$me = $facebook->api('/me');
...

The problem is that $fb_sess is always 0, so empty($fb_sess) is always true, and so the redirect to the login URL repeats Endlessly. my app seems to be correctly configured and i'm using the latest PHP SDK. any clue to fix that or at least get an idea of what's happening?

Answer 1

You are missing redirect_uri param. Add redirect_uri

$params = array(
'scope' => 'email',
     'response_type'=>'token',
'redirect_uri' => 'http url after login',
);

So this will confirm after login only the user is returned to the page.

Answer 2

I realize this question is old, but I will answer it in case someone comes here from google (as I did).

First of all, comment out this line:

header("Location: $url");

and replace it with something like this:

echo "the user appears to be empty try to <a href=".$url.">login</a>";

This way you have the opportunity to see if there's a problem and the user won't get lost in an endless redirection loop. Most likely the error message will be appended to the URL, it'll look something like this:

error_code=901&error_message=This+app+is+in+sandbox+mode.++Edit+the+app+configuration+at+http%3A%2F%2Fdevelopers.facebook.com%2Fapps+to+make+the+app+publicly+visible

The problem in this example is the app is in sandbox mode.