canvas #facebook login app example

<?php
require 'admin/config.facebook.php';

use Facebook\Facebook;

$fb = new Facebook([
  'app_id' => $cnf["fb_appid"],
  'app_secret' => $cnf["fb_appsecret"],
  'default_graph_version' => 'v2.4',
]);

$permissions = array(
  'scope' => 'public_profile, email, user_friends'
);

$helper = $fb->getCanvasHelper();

try {
  $accessToken = $helper->getAccessToken();
} catch(Facebook\Exceptions\FacebookResponseException $ex) {
  echo $ex->getMessage();
} catch(Facebook\Exceptions\FacebookSDKException $ex) {
  echo $ex->getMessage();
}

if (isset($accessToken)) {
  $fb->setDefaultAccessToken((string)$accessToken);
  $response = $fb->get('/me?locale=en_US&fields=id,name,email');
  $userNode = $response->getGraphUser();

  $fbid = $userNode->getProperty('id');              // To Get Facebook ID
  $fbfullname = $userNode->getProperty('name'); // To Get Facebook full name
  $femail = $userNode->getProperty('email');    // To Get Facebook email ID

  $_SESSION['FBID'] = $fbid;
  $_SESSION['FULLNAME'] = $fbfullname;
  $_SESSION['EMAIL'] = $femail;
  $_SESSION['TOKEN'] = $accessToken;
  $_SESSION['login_3rd'] = "fb";
  header("Location: /home");
}