SLIM3 opauth login facebook problem

Someone here can help me with this code?

it does not work:

    if (!empty ($username = $info['email'])) $this->@$info['email'] = $username->email;

    else  {
    $username = 'facebook-oauth-uid-'.$oauth_id;

    }

I’d like to check if there an email if not I’d set username = uid.

Do you have a php/slim example for that?

Thanks!