Google OAuth2 Callback

gistfile1.txt

<?php
require_once __DIR__.'/vendor/autoload.php';

session_start();

$client = new Google_Client();
$client->setAuthConfigFile('client_secrets.json');
$client->setRedirectUri('https://' . $_SERVER['HTTP_HOST'] . '/oauth2callback');
$client->addScope('https://www.googleapis.com/auth/plus.login');
$client->addScope('https://www.googleapis.com/auth/plus.me');
$client->addScope('https://www.googleapis.com/auth/userinfo.email');
$client->addScope('https://www.googleapis.com/auth/userinfo.profile');
$client->setAccessType('online');
$client->setIncludeGrantedScopes(false);

if (!isset($_GET['code'])) {
  $auth_url = $client->createAuthUrl();
  header('Location: ' . filter_var($auth_url, FILTER_SANITIZE_URL));
} else {
  $credentials = $client->authenticate($_GET['code']);
  if (isset($credentials['error']))
  {
    echo 'Error: ' . $credentials['error'] . ' Description: ' . $credentials['error_description'];
  }
  else
  {
    $_SESSION['access_token'] = $client->getAccessToken();
    echo 'Success';
  }
}
?>