How can I pass value to FacebookRedirectLoginHelper in PHP

Question

I use Facebook PHP SDK and trying to send token-id from one page to another. I use this code - http://www.krizna.com/demo/login-with-facebook-using-php/. I use

$helper = new FacebookRedirectLoginHelper('http://www.krizna.com/fbconfig.php' );

I have tried sending value like this :

$helper = new FacebookRedirectLoginHelper('http://www.krizna.com/fbconfig.php?value='.$value );  

but I do not get value in fbconfig.php file when I try:

$value = $_GET['value'];

I have also used session for sending values but it does not work. How can I send value to FacebookRedirectLoginHelper (fbconfig.php)?

fbconfig.php

<?php

session_start();

$value = $_GET['value_new'];

$fb = new \Facebook\Facebook([
    'app_id' => $config->facebook->app_id,
    'app_secret' => $config->facebook->app_secret
]);

$helper = $fb->getRedirectLoginHelper();
try {
    if ($access_token = $helper->getAccessToken()) {

        try {
            // Returns a `Facebook\FacebookResponse` object with the requested fields
            $response = $fb->get('/me?fields=name,id,email,picture', $access_token);
            $user = $response->getGraphUser();
            $fbid = $user->getId();            // To Get Facebook ID
            $fbfullname = $user->getName();    // To Get Facebook full name
            $femail = $graphObject->getEmail();// To Get Facebook email ID
            $_SESSION['FBID'] = $fbid;
            $_SESSION['FULLNAME'] = $fbfullname;
            $_SESSION['EMAIL'] = $femail;
            //Then do whatever you want with that data

            $value = $_SESSION['value'];

            header("Location: index.php?value_new=$value");

            } catch (\Facebook\Exceptions\FacebookResponseException $e) {
            error_log('Graph returned an error: ' . $e->getMessage());
        } catch (\Facebook\Exceptions\FacebookSDKException $e) {
            error_log('Facebook SDK returned an error: ' . $e->getMessage());
        }
    }
} catch (\Facebook\Exceptions\FacebookResponseException $e) {
    // When Graph returns an error
    error_log('Graph returned an error: ' . $e->getMessage());
} catch (\Facebook\Exceptions\FacebookSDKException $e) {
    // When validation fails or other local issues
    error_log('Facebook SDK returned an error: ' . $e->getMessage());
}

index.php

<?php if (isset($_SESSION['FBID'])): ?><!--  After user login  -->
<div class="container">
    <h1>value <?php $value_new = $_GET['value_new']; echo $value_new; ?></h1>
</div>
<? endif ?>

Answer 1

You should not be trying to pass the facebook Access Token via the query string / $_GET[] superglobal. What you should be using is what facebook recommends, which is the $_SESSION[] superglobal.

Since you are trying to pass the access token from one page to another, lets call the access token on the first page $access_token. To pass it to another page do the following:

page 1:

<?php 
  session_start(); //the very top of your document
  // ... other code ...
  $_SESSION['access_token'] = $access_token;
  // ... other code ...
?>

page 2:

<?php 
  session_start(); //the very top of your document
  // ... other code ...
  $access_token = $_SESSION['access_token'];
  // ... other code ...
?>

That should work, let me know if it works for you.

Answer 2

This answer is using the Facebook PHP SDK v5.1.2, and is adapted from the method I have working in my own projects. It also assumes composer autoloading is being used.

Login Page

session_start();
$fb = new \Facebook\Facebook([
    'app_id' => $config->facebook->app_id, //Change these to yours
    'app_secret' => $config->facebook->app_secret
]);

$helper = $fb->getRedirectLoginHelper();
$permissions = ['email'];
$this->view->facebook_url = $helper->getLoginUrl('http://www.krizna.com/fbconfig.php', $permissions);

fbconfig.php (or whatever you want your redirect page to be)

session_start();
$fb = new \Facebook\Facebook([
    'app_id' => $config->facebook->app_id,
    'app_secret' => $config->facebook->app_secret
]);

$helper = $fb->getRedirectLoginHelper();
try {
     if ($access_token = $helper->getAccessToken()) {

        try {
            // Returns a `Facebook\FacebookResponse` object with the requested fields
            $response = $fb->get('/me?fields=name,id,email,picture', $access_token);
            $user = $response->getGraphUser();
            $fbid = $user->getId();              // To Get Facebook ID
            $fbfullname = $user->getName(); // To Get Facebook full name
            $femail = $graphObject->getEmail();    // To Get Facebook email ID
            $_SESSION['FBID'] = $fbid;           
            $_SESSION['FULLNAME'] = $fbfullname;
            $_SESSION['EMAIL'] =  $femail;
            //Then do whatever you want with that data
        } catch(\Facebook\Exceptions\FacebookResponseException $e) {
            error_log('Graph returned an error: ' . $e->getMessage());
        } catch(\Facebook\Exceptions\FacebookSDKException $e) {
            error_log('Facebook SDK returned an error: ' . $e->getMessage());
        }
    }

} catch (\Facebook\Exceptions\FacebookResponseException $e) {
    // When Graph returns an error
    error_log('Graph returned an error: ' . $e->getMessage());
} catch (\Facebook\Exceptions\FacebookSDKException $e) {
    // When validation fails or other local issues
    error_log('Facebook SDK returned an error: ' . $e->getMessage());
}

Hopefully that gives you a hand up. I don't doubt that my code has been adapted from previous StackOverflow answers or tutorials.