Question

I am using the following code to post to my facebook fan page and it is working fine. Now I want to use cronjob in order to post to Facebook. I know I have to use as access token but I am not sure how to set it up. I tried to use echo my own access token and the page’s access token and use it in the post api but that did not work I got this error:

Uncaught OAuthException: An active access token must be used to query information about the current user.

Here is my code that I tried:

require_once('scripts/facebook.php');
    $config = array('appId' => 'xxx','secret' => 'xxx');

    $params = array('scope'=>'user_likes,publish_actions,email,offline_access,publish_stream,manage_pages');
    $facebook = new Facebook($config);
    $user = $facebook->getUser();
    if($facebook->getUser()) {
    try {

        $user_profile = $facebook->api('/me');
        $access_token = $facebook->getAccessToken();
        //echo "1. ".$access_token;

      } catch(FacebookApiException $e) {
                        $login_url = $facebook->getLoginUrl($params);
                        error_log($e->getType());
                        error_log($e->getMessage());
      }   
    } else {
        $login_url = $facebook->getLoginUrl($params);

    }    

$page_id = "xxxxxxxxxxxxx";
            $page_access_token = "";
            $result = $facebook->api("/me/accounts");
            foreach($result["data"] as $page) {
                if($page["id"] == $page_id) {
                $page_access_token = $page["access_token"];
                //echo '<br>';
                //echo "2. ".$page_access_token;
                break;
                    }
                }


        $args = array(
            'access_token'  => 'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx',
            'message'       => stripslashes($image_caption).$animaged_gif,
            'name' => stripslashes($image_caption).$animaged_gif,
            'link' => "http://www.example.com/images.php?i=".$image_name,
            'picture' => "http://www.example.com/thumbnails/".$image_name.".png",
            'actions' => array(
            'name' => 'See Pic',
            'link' => "http://www.example.com/images.php?i=".$image_name
            )

        );
       $post = $facebook->api("/$page_id/feed","post",$args);

As you can see that I tried to use the actual access token that I got when I echo out my own access token. But that did not work. I also used the page’s access token, but that also did not work. Can you please tell what I am missing here or what is the proper way to do this ?
After some further search I did, I came across setAccessToken and $page_info = $fb->api("/".$sInfo['pageId']."?fields=access_token"); but there is very limited resources on how to use them. I am not even sure if those will be appropriate to this problem. All I need to know is which access token I need to use and what is the appropriate code to set it up ?

Answer 1

This is how you can do it :

1. Get a short lived accesstoken.
2. Extend it.
3. Get a long lived page accesstoken. (Doesn’t matter, here we are going to fetch new accesstoken every time. Less complicated, and reliable.)

Thought I would go with an algo, instead I am adding all the possible codes and documentations since this may help someone else too.

Getting short lived access token and extending it:

fetchtoken.php

<?php

//read more : https://developers.facebook.com/docs/howtos/login/server-side-login/
session_start();
$app_id = "xxxxxxxxxxxxxx";
$app_secret = "xxxxxxxxxxxxxxxx";
$my_url = "www.stackoverflow.com/";  // redirect url

$code = $_REQUEST["code"];

if(empty($code)) {
    // Redirect to Login Dialog
    $_SESSION['state'] = md5(uniqid(rand(), TRUE)); // CSRF protection
    $dialog_url = "https://www.facebook.com/dialog/oauth?client_id=" 
       . $app_id . "&redirect_uri=" . urlencode($my_url) . "&state="
       . $_SESSION['state'] . "&scope=publish_stream,read_friendlists,email";


    echo("<script> top.location.href='" . $dialog_url . "'</script>");
}
if($_SESSION['state'] && ($_SESSION['state'] === $_REQUEST['state'])) {
    $token_url = "https://graph.facebook.com/oauth/access_token?"
       . "client_id=" . $app_id . "&redirect_uri=" . urlencode($my_url)
       . "&client_secret=" . $app_secret . "&code=" . $code;

     $response = file_get_contents($token_url);
     $params = null;
     parse_str($response, $params);
     $longtoken=$params['access_token'];


//save it to database   
} 
?>

So you now have a long lived accesstoken ready in your database, a text file or whatever.

cronjob.php

<?
require_once('scripts/facebook.php');
// Pull access token from the file/db
$access_token = "access token from file or db";
$facebook->setAccessToken($access_token); // sets our access token as the access token when we call something using the SDK, which we are going to do now.

$config = array('appId' => 'xxx','secret' => 'xxx');

$params = array('scope'=>'user_likes,publish_actions,email,publish_stream,manage_pages');
$facebook = new Facebook($config);
$user = $facebook->getUser();
if($facebook->getUser()) {
    try {

        $user_profile = $facebook->api('/me');
    } catch(FacebookApiException $e) {
        $login_url = $facebook->getLoginUrl($params);
        error_log($e->getType());
        error_log($e->getMessage());
    }   
}
else {
    $login_url = $facebook->getLoginUrl($params);
}    

$page_id = "xxxxxxxxxxxxx";
$page_access_token = "";
$result = $facebook->api("/me/accounts");
foreach($result["data"] as $page) {
    if($page["id"] == $page_id) {
        $page_access_token = $page["access_token"];
        //echo '<br>';
        //echo "2. ".$page_access_token;
        break;
    }
}

$args = array(
    'access_token'  => $page_access_token,
    'message'       => stripslashes($image_caption).$animaged_gif,
    'name' => stripslashes($image_caption).$animaged_gif,
    'link' => "http://www.example.com/images.php?i=".$image_name,
    'picture' => "http://www.example.com/thumbnails/".$image_name.".png",
    'actions' => array(
            'name' => 'See Pic',
             'link' => "http://www.example.com/images.php?i=".$image_name
    )
);
$post = $facebook->api("/$page_id/feed","post",$args);
?>

Make sure you don’t grab access_token(user access token / $access_token) again in the script.

Also, the access_token in $args which is the page access token should be inserted by the $page_access_token variable, and not manually.

Having offline_access in the scope does nothing than showing them on the permission dialogue box that their data can be accessed any time which can be done without that notification anyway.

This should work as long as you visit the fetch.php once at the start, and once every 60 days manually.

Let me know.