PHP/Graph API : Why my facebook session doesn't work's? - php

Question

I'm a new developper on Facebook Graph API. I have follow this tutorial : https://www.webniraj.com/2014/05/01/facebook-api-php-sdk-updated-to-v4-0-0. I have test once and it works. I have modify and retest and it's work. But, the next day, nothing... My session token for facebook have change and I don't know why and how.
There is my code :
// ALL includes and variables
// start session
session_start();
// init app with app id and secret
FacebookSession::setDefaultApplication( $app_ID, $app_secret );
// login helper with redirect_uri
$helper = new FacebookRedirectLoginHelper( $url );
// generate login url with scope, each permission as element in array
$loginUrl = $helper->getLoginUrl( array($access_right) );
// see if a existing session exists
if ( isset( $_SESSION ) && isset( $_SESSION['fb_token'] ) ) {
// create new session from saved access_token
$session = new FacebookSession( $_SESSION['fb_token'] );
// validate the access_token to make sure it's still valid
try {
if ( !$session->validate() ) {
$session = null;
}
} catch ( Exception $e ) {
// catch any exceptions
$session = null;
}
}
if ( !isset( $session ) || $session === null ) {
// no session exists
try {
$session = $helper->getSessionFromRedirect();
} catch( FacebookRequestException $ex ) {
// When Facebook returns an error
// handle this better in production code
print_r( $ex );
} catch( Exception $ex ) {
// When validation fails or other local issues
// handle this better in production code
print_r( $ex );
}
}
// see if we have a session
if ( isset( $session ) ) {
// save the session
$_SESSION['fb_token'] = $session->getToken();
// create a session using saved token or the new one we generated at login
$session = new FacebookSession( $session->getToken() );
// graph api request for user data
$graphObject = (new FacebookRequest( $session, 'GET', '/me/accounts'))->execute()->getGraphObject()->asArray();
// print profile data
echo '<pre>' . print_r( $graphObject, 1 ) . '</pre>';
$page_token = $graphObject['data'][0]->access_token;
echo '<p>Page token : '.$page_token.'</p>';
$session = new FacebookSession($page_token);
/* make the API call */
$request = new FacebookRequest(
$session,
'POST',
'/'.$pageID.'/feed',
array (
'message' => 'This is a test message',
)
);
$response = $request->execute();
$graphObject = $response->getGraphObject();
/* handle the result */
// print profile data
echo '<pre>' . print_r( $graphObject, 1 ) . '</pre>';
// print logout url using session and redirect_uri (logout.php page should destroy the session)
echo 'Logout';
} else {
// show login url
echo 'Login';
}
My goal is just to put a message on my fan page, and it works the first time. Why the variable "$_SESSION['fb_token']" is now NULL ?? How I can make it work ?
Thanks for response !
Edit 1 :
I discovered that my session have change the CSRF title : 'fb_token' to 'FBRLH_state'. An idea about this change ?

Answer 1

Here is the content of a file I have that logs in users using the latest Facebook PHP-SDK 4.0.9 (I think).
<?php
require_once( 'Facebook/FacebookSession.php' );
require_once( 'Facebook/FacebookRedirectLoginHelper.php' );
require_once( 'Facebook/FacebookRequest.php' );
require_once( 'Facebook/FacebookResponse.php' );
require_once( 'Facebook/FacebookSDKException.php' );
require_once( 'Facebook/FacebookRequestException.php' );
require_once( 'Facebook/FacebookAuthorizationException.php' );
require_once( 'Facebook/GraphObject.php' );
require_once( 'Facebook/GraphUser.php' );
use Facebook\FacebookSession;
use Facebook\FacebookRedirectLoginHelper;
use Facebook\FacebookRequest;
use Facebook\FacebookResponse;
use Facebook\FacebookSDKException;
use Facebook\FacebookRequestException;
use Facebook\FacebookAuthorizationException;
use Facebook\GraphObject;
use Facebook\GraphUser;
if (!isset($_SESSION['facebookUserId']) || !isset($_SESSION['facebookSession']) || !isset($_SESSION['facebookUserProfile'])) {
// init app with app id (APPID) and secret (SECRET)
FacebookSession::setDefaultApplication($appId,$appSecret);
// login helper with redirect_uri
$helper = new FacebookRedirectLoginHelper( $canvasUrl );
try {
$FBSession = $helper->getSessionFromRedirect();
} catch( FacebookRequestException $ex ) {
// When Facebook returns an error
} catch( Exception $ex ) {
// When validation fails or other local issues
}
if (!isset($FBSession)) {
// STEP ONE - REDIRECT THE USER TO FACEBOOK FOR AUTO LOGIN / APP APPROVAL
header('Location: ' . $helper->getLoginUrl());
exit();
} else {
$user_profile = (new FacebookRequest($FBSession, 'GET', '/me'))->execute()->getGraphObject(GraphUser::className());
$_SESSION['facebookUserId'] = $user_profile->getID();
$_SESSION['facebookSession'] = $FBSession; // I DON'T THINK THIS ACTAULLY WORKS RIGHT
$_SESSION['facebookUserProfile'] = $user_profile;
}
}
I simply include this file as seen below.
include ('SimpleFacebookLogin.php');
I try to save the session and it doesn't save properly in the session so I think I am missing something as well but I can successfully log in after creating a session. I am just not sure how to access it again afterward. I hope this helps.

Answer 2

Actualy works! =) Session is saved on my pc with this piece of script.
I added session_start() and session_write_close() - maybe you missed those?