Facebook PHP SDK和页面选项卡； 授权过程后，getUser（）始终返回0

Question

I'm a PHP developer and I have nice experience with Facebook PHP SDK, but this time I'm lost :(

My problem is the following: I'm developing a facebook page tab application with Laravel, a PHP framework. This is my code:

    //getting the Facebook class instance
    $facebook = IoC::resolve('facebook-sdk');

    if(!$facebook->getUser()){
        $pagetab_url = 'https://www.facebook.com/PAGEUSERNAME?sk=app_APPID';    

        $loginUrlParams = array(
               'scope' => 'publish_stream',
               'redirect_uri' => $pagetab_url
        );

        $loginUrl = $facebook->getLoginUrl($loginUrlParams);

        echo("<script> top.location.href='" . $loginUrl . "'</script>");
    }
    else{
        echo $facebook->getUser();
    }

This code generates an infinite loop, because $facebook->getUser() always returns zero. AppId and AppSecret are correct, infact, if I change 'redirect_uri' to any page of my app domain, it works (for example: 'redirect_uri' => ' https://www.mysite.com/fb_callback ').

Additional details: the signed request is always null. Do you have any idea?

Many thanks!

EDIT This solved my problem Facebook iframe tab signed request always empty

Answer 1

I think rather than injecting a script which reloads the page, you need to give the user a chance to log into your app and authorize it.

Am I missing something? (You'll never get a result from $facebook->getUser() call unless the user is logged in AND has authorized your app).

Lastly, is there any reason you don't use:

header('Location: '.$loginUrl) ?

Instead of injecting javascript?

Are you developing on more than one server? (Localhost and a test server perhaps?) Another possibility is that you are testing on two different domains (localhost vs stage.whatever.com, for example) and you need to give your app permission to work on both domains.

Basically, log errors, if any, from the getUser() call and see what that output is.