How To Add Facebook SDK v5 Login to PHP Website

Last updated on November 20, 2017

Nowadays social media login are everywhere and users are not interested in filling a lengthy form to register. Most of the popular websites are already providing Facebook login feature. So in this post, I would like to show you, Facebook login integration steps using PHP.

To get started with the latest version of Facebook SDK v5.X, make sure your system meets the following requirements.

PHP version should be 5.4 or greater.
The mbstring extension should be enabled.

This post assumes that you have prior knowledge of the composer. So let’s get started.

Step 1: Goto https://developers.facebook.com/apps/ and Click Add a New App .
» Choose Website
» Choose Name for you App and Click Create New Facebook App ID
» Choose a category for you App and click Create App ID
» Now Click Skip Quick Test

Step 2 Under settings, Provide values for App domain ( Eg: arjunphp.com ) and Contact Email and click Add Platform.

Provide Values for Site URL and Mobile site URl ( Optional )

Step 3 By default your app enabled for sandbox mode you need to change it to live. To make it live, click on Status & Review tab and click the button to make you App live.

That’s it App settings done now come to the coding.

Step 4 The Facebook PHP SDK can be installed with Composer. Run this command:

composer require facebook/graph-sdk

Step 5:

 FB_APP_ID,
  'app_secret' => FB_APP_SECRET,
  'default_graph_version' => FB_APP_GRAPH_VERSION,
  //'default_access_token' => '{access-token}', // optional
]);

$helper = $fb->getRedirectLoginHelper();

if(!$_GET['code']) {

  $permissions = ['email', 'user_posts']; // optional

  $loginUrl    = $helper->getLoginUrl(FB_APP_CALLBACK_URL, $permissions);
  
  echo 'Log in with Facebook!';
} else {

  try {
    // get user access token
     $accessToken = $helper->getAccessToken();

     // store access token in the user session. 
     $_SESSION['facebook_access_token'] = (string) $accessToken;

  } catch(Facebook\Exceptions\FacebookSDKException $e) {
    // There was an error communicating with Graph
    echo $e->getMessage();
    exit;
  }

  if($_SESSION['facebook_access_token']) {
    // User authenticated your app!
    // Save the access token to a session and redirect
    try {
      // Get the \Facebook\GraphNodes\GraphUser object for the current user.
      // If you provided a 'default_access_token', the '{access-token}' is optional.
      $response = $fb->get('/me?fields=id,name,email', $_SESSION['facebook_access_token']);

      // get current user info object
      $me = $response->getGraphUser();

      // echo current user name and email
      echo 'Logged in as ' . $me->getName() .' '. $me->getEmail();


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