Question

I’m tired of digging through tons of tutorials/documentations which don’t help me at all.

What I have now (everything is placed inside admin control panel):

1. If user is logged on correct account (administrator of page with granted rights), everything works fine, post on page is posted as impersonated site.
2. If he is logged on other account, nothing happens. Site redirects him to his wall.
3. If he isn’t logged on any account, he’s redirected to facebook login – if he logs onto correct account, he returns to acp (it’s bad solution, because it’ll clear his form)

I want to achieve:

1. If logged in, everything as it was
2. Else popup with login to specific (correct) account

At the moment I’m using only PHP, but solution with JS is permitted.

My code:

<?php
/*(...)*/
$facebook = new Facebook(array(
      'appId'  => $apiid,
      'secret' => $secret,
      'cookie' => true,
    ));

    $session = $facebook->getSession();
    $me = null;
    if ($session) {
        try {
            $uid = $facebook->getUser();
            $me = $facebook->api('/me');
        } catch (FacebookApiException $e) {
            error_log($e);
        }

        if($me) {


            //In order to post to the page later on we need to generate an Access Token for that page, to do this we get me-accounts in the following api call
            $accounts = $facebook->api('/me/accounts');

            //Loop through the array off accounts to find the page with a matching ID to the one we need
            foreach($accounts['data'] as $account){
              if($account['id'] == PAGEID){
                $ACCESS_TOKEN = $account['access_token'];
                }
            }
        }

        $message=$data['facebook_text'];
        $attachment = array(
            'message' => $data['facebook_text'],
            'name' => $data['name'],
            'description' => '',
            'link'=>$someurl,
            'access_token' => $ACCESS_TOKEN
        );
        if($image_url != NULL) $attachment['picture'] = $image_url;

        try {
            if($facebook->api('/PAGEID/feed', 'post', $attachment))
            {
                //other stuff
            }
        } catch (FacebookApiException $e) {
            error_log($e);
            //other stuff
        }
    }
    else
    {
        $login_url = $facebook->getLoginUrl();
        header("Location: $login_url");
        exit;
    }
/* (...) */
?>

Solution can’t redirect anywhere, because it’s inside form, so all data’ll be lost.

Answer 1

I’m not really sure I understand what you want to do here, but this is what I use in a similar situation:

$session = $this->get_admin_session_of_page ($page_id);
$session = unserialize ($session);
$facebook->setSession ($session, false);

In the facebook php SDK there is a method to manually set the session, setSession. I save the page admin user session in DB with serialize, with the offline access and manage pages permission. Then when you need some admin privileges for the application you just unserialize it, and then use setSession. The second parameter is set to FALSE, so that this session is not saved in a cookie and logout the current user.

This way it’s not important who is logged in, the work is always done as an admin of the page. I think this is safe to use in an automated script, for example to upload a user photo in a page album.
Of course, you must use caution with this if it gets more involved then that, or implement your own security.