<?php session_start(); // added in v4.0.0 require_once
'facebook/autoload.php';
use FacebookFacebookSession;
use FacebookFacebookRedirectLoginHelper;
use FacebookFacebookRequest;
use FacebookFacebookResponse;
use FacebookFacebookSDKException;
use FacebookFacebookRequestException;
use FacebookFacebookAuthorizationException;
use FacebookGraphObject;
use FacebookEntitiesAccessToken;
use FacebookHttpClientsFacebookCurlHttpClient;
use FacebookHttpClientsFacebookHttpable; // init app with app id and secret
FacebookSession::setDefaultApplication('id','secret key');
// login helper with redirect_uri
$helper = new FacebookRedirectLoginHelper('http://localhost//myaap/facebook/fbconfig.php');
try {   $session = $helper->getSessionFromRedirect(); }
catch( FacebookRequestException $ex )
{   // When Facebook returns an error
} catch( Exception $ex )
{
    // When validation fails or other local issues
}
// see if we have a session
if ( isset( $session ) ) {   // graph api request for user data
     $request = new FacebookRequest( $session, 'GET', '/me' );
     $response = $request->execute();   // get response
     $graphObject = $response->getGraphObject();
     $fbid = $graphObject->getProperty('id');  // To Get Facebook ID
     $fbfullname = $graphObject->getProperty('name'); // To Get Facebook full name
     $femail = $graphObject->getProperty('email');    // To Get Facebook email ID   /* ---- Session Variables -----*/
    $_SESSION['FBID'] = $fbid;
    $_SESSION['FULLNAME'] = $fbfullname;
    $_SESSION['EMAIL'] =  $femail;
/* ---- header location after session ----*/
header("Location: index.php"); }
else {
    $loginUrl = $helper->getLoginUrl();
    header("Location: ".$loginUrl);
}