Get Facebook Access Token Using PHP SDK v5

In my previous tutorial How to Auto Post on Facebook Using PHP, I have explained Auto Post on Facebook using PHP SDK v3.2.3. Now in this post I will show you, how you get Facebook Access Token using PHP SDK v5.0. Facebook access token is required to post on user’s Facebook timeline/wall.

Create Facebook APP:
To get the Facebook Access token you need to create Facebook App. To create a Facebook App please follow the steps of previous post How to Auto Post on Facebook Using PHP and get the App ID and App secret key.

Get Facebook Access Token:
Now to get Facebook Access Token you need to use a PHP SDK (v5.0) to communicate with Facebook API. You can download PHP SDK 5.0 from following link Download Facebook PHP SDK v5.0.

System Requirements:
1. PHP 5.4 or greater
2. The Curl extension
3. The mbstring extension

Now create a file getAccessToken.php and write the code as below to request for Facebook Access Token.

require_once __DIR__ . '/FacebookSDK/src/Facebook/autoload.php';

$fbData = array(
	'consumer_key' => APP_ID,
	'consumer_secret' => APP_SECRET,
	'default_graph_version' => 'v2.2'
);

$fb = new Facebook\Facebook($fbData);

$params = array('req_perms' => 'publish_actions');
$helper = $fb->getRedirectLoginHelper();
$loginUrl = $helper->getLoginUrl('callback.php', $params);

header('Location: '. $loginUrl);
exit;

You will see the screen like below. Now you need to allow permission by click on Okay.

Before click on Okay, create a callback.php page with following code:

require_once __DIR__ . '/FacebookSDK/src/Facebook/autoload.php';

$fbData = array(
	'consumer_key' => APP_ID,
	'consumer_secret' => APP_SECRET,
	'default_graph_version' => 'v2.2'
);

$fb = new Facebook\Facebook($fbData);

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

  // this token will be valid for next 2 hours

} 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;
}

Now to extend the validity of this access token use following code after getting access token.

// OAuth 2.0 client handler
$oAuth2Client = $fb->getOAuth2Client();

// Exchanges a short-lived access token for a long-lived one
$accessToken = $oAuth2Client->getLongLivedAccessToken($accessToken);

Now the access toke will be valid for next 60 days. You can save this access token and use for the auto post on user’s facebook timeline.

I hope this tutorial will help you to get the Facebook Access Token of the user using PHP SDK v5.