Facebook PHP SDK：“ iframe”页面标签上的用户ID

Question

I'm on my own page, I'm admin and I'm already "like" this peage, but this code:

require_once "api/facebook.php";

$facebook = new Facebook(array(
    'appId'  => APP_ID,
    'secret' => SECRET,
    'cookie' => true
));

$signedrequest = $facebook->getSignedRequest();
$uid = $facebook->getUser();

gives me just this data:

### USER ID ###

0

### SIGNED REQUEST ###

Array
(
    [algorithm] => HMAC-SHA256
    [issued_at] => 1330166798
    [page] => Array
        (
            [id] => 304887859549216
            [liked] => 1
            [admin] => 1
        )

    [user] => Array
        (
            [country] => us
            [locale] => en_US
            [age] => Array
                (
                    [min] => 21
                )
        )
)

So, getUser() = 0 and user id from signed request - empty. What im doing wrong?

Answer 1

By default the "user" is the page, this way you can display content from your app relevant to the page. To determine who the user is, you can go through the standard backend redirects you would go through as if the user came to your app with no session/expired token. But you need to remember what page your were on since Facebook only passes that information on initial iframe load.

For a better user experience, I would use the Facebook javascript SDK. You can check everything in javascript and determine who the user is without performing any redirects. You can even prompt for authorization without reloading the page. If the user already had authorized your app, they see no changes and get no prompts, but you now have a "session" with that user and know their ID in javascript.

https://developers.facebook.com/docs/reference/javascript/FB.login/

Answer 2

Just to add to this you can't currently get everything in the javascript SDK. It doesn't give you any of the user or page (for page tab) data which PHP SDK does.

Answer 3

对于getUser，您需要登录您的应用程序，显示te login / permission对话框。