Login with Facebook in CodeIgniter

Facebook Login Integration is the most used feature of today’s web application. Login with Facebook feature helps the user to log into the web application without prior account registration. This means that your web application will get more users/customers. We’ve already published Login with Facebook using PHP tutorial that helps to implement Facebook login in PHP application. In this tutorial, we’re going to explain how to integrate Facebook Login in CodeIgniter framework using Facebook PHP SDK and Graph API.

In the example CodeIgniter Facebook OAuth application, we will implement user authentication with Facebook PHP Graph SDK v5.x and store the user’s profile information in the MySQL database. Before you begin to integrate Facebook Login in CodeIgniter, take a look at the files structure of the application.

codeigniter_facebook_login/
├── application/
│   ├── config/
│   │   └── facebook.php
│   ├── controllers/
│   │   └── User_authentication.php
│   ├── libraries/
│   │   └── Facebook.php
│   ├── models/
│   │   └── User.php
│   ├── third_party/
│   │   └── facebook-php-graph-sdk/
│   └── views/
│       └── user_authentication/
│           └── index.php
└── assets/
    ├── css/
    │   └── style.php
    └── images/
        └── fb-login-btn.png

Create Facebook App

To getting started to implement Facebook login in CodeIgniter 3 using PHP SDK, you need to create a Facebook App in the Facebook developers panel and get the App ID and App Secret. The App ID and App Secret are required to connect with Facebook OAuth API and Graph API through PHP SDK. Go through the below tutorial for a step-by-step guide to create Facebook App, App ID, and App Secret.

• How to Create Facebook App, App ID, and App Secret

Once your Facebook app creation is completed, copy the App ID and App Secret for later use in the script.

Note that: The App ID and App secret need to be specified in the Facebook API configuration file. Also, the Valid OAuth Redirect URIs must be matched with the user authentication controller (ex: https://www.codexworld.com/user_authentication/).

Create Database Table

To store the user’s Facebook profile data, a table needs to be created in the database. The following SQL creates an users table with some basic fields in the MySQL database.

CREATE TABLE `users` (
 `id` int(11) NOT NULL AUTO_INCREMENT,
 `oauth_provider` enum('facebook','google','twitter','') COLLATE utf8_unicode_ci NOT NULL DEFAULT '',
 `oauth_uid` varchar(50) COLLATE utf8_unicode_ci NOT NULL,
 `first_name` varchar(25) COLLATE utf8_unicode_ci NOT NULL,
 `last_name` varchar(25) COLLATE utf8_unicode_ci NOT NULL,
 `email` varchar(25) COLLATE utf8_unicode_ci NOT NULL,
 `gender` varchar(10) COLLATE utf8_unicode_ci DEFAULT NULL,
 `picture` varchar(200) COLLATE utf8_unicode_ci NOT NULL,
 `link` varchar(100) COLLATE utf8_unicode_ci NOT NULL,
 `created` datetime NOT NULL,
 `modified` datetime NOT NULL,
 PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;

Config (application/config/)

autoload.php
In the config/autoload.php file, define the commonly used library (database and session) and helper (url) to load automatically on every request.

$autoload['libraries'] = array('session','database');
$autoload['helper'] = array('url');

facebook.php
In the config/facebook.php file, the Facebook App and API configurations are defined. Specify the App ID, App Secret and Redirect URL according to your Facebook App credentials.

<?php
defined('BASEPATH') OR exit('No direct script access allowed');

/*
| -------------------------------------------------------------------
|  Facebook API Configuration
| -------------------------------------------------------------------
|
| To get an facebook app details you have to create a Facebook app
| at Facebook developers panel (https://developers.facebook.com)
|
|  facebook_app_id               string   Your Facebook App ID.
|  facebook_app_secret           string   Your Facebook App Secret.
|  facebook_login_redirect_url   string   URL to redirect back to after login. (do not include base URL)
|  facebook_logout_redirect_url  string   URL to redirect back to after logout. (do not include base URL)
|  facebook_login_type           string   Set login type. (web, js, canvas)
|  facebook_permissions          array    Your required permissions.
|  facebook_graph_version        string   Specify Facebook Graph version. Eg v3.2
|  facebook_auth_on_load         boolean  Set to TRUE to check for valid access token on every page load.
*/
$config['facebook_app_id']                = 'Insert_Facebook_App_ID';
$config['facebook_app_secret']            = 'Insert_Facebook_App_Secret';
$config['facebook_login_redirect_url']    = 'user_authentication/';
$config['facebook_logout_redirect_url']   = 'user_authentication/logout';
$config['facebook_login_type']            = 'web';
$config['facebook_permissions']           = array('email');
$config['facebook_graph_version']         = 'v3.2';
$config['facebook_auth_on_load']          = TRUE;

Third Party (application/third_party/)

facebook-php-graph-sdk/
The facebook-php-graph-sdk/ directory contains the latest version (v5) of Facebook SDK for PHP. Facebook PHP SDK is used to connect with the Facebook Graph API and integrate login system with Facebook.

Note that: The Facebook PHP SDK needs to be placed in the third_party/ directory of your CodeIgniter application. You don’t need to download the Facebook PHP SDK library separately, all the required files are included in the source code.

Libraries (application/libraries/)

Facebook.php
The Facebook OAuth library helps to integrate Facebook PHP SDK v5 in CodeIgniter 3.x application. Using this Facebook class, you can easily add the login with Facebook functionality using PHP SDK v5 to the CodeIgniter application.

<?php 
defined('BASEPATH') OR exit('No direct script access allowed'); 
 
/** 
 * Facebook PHP SDK v5 for CodeIgniter 3.x 
 * 
 * Library for Facebook PHP SDK v5. It helps the user to login with their Facebook account 
 * in CodeIgniter application. 
 * 
 * This library requires the Facebook PHP SDK v5 and it should be placed in libraries folder. 
 * 
 * It also requires social configuration file and it should be placed in the config directory. 
 * 
 * @package     CodeIgniter 
 * @category    Libraries 
 * @author      CodexWorld 
 * @license     http://www.codexworld.com/license/ 
 * @link        http://www.codexworld.com 
 * @version     3.0 
 */ 
 
// Include the autoloader provided in the SDK 
require_once APPPATH .'third_party/facebook-php-graph-sdk/autoload.php';  
 
use Facebook\Facebook as FB; 
use Facebook\Authentication\AccessToken; 
use Facebook\Exceptions\FacebookResponseException; 
use Facebook\Exceptions\FacebookSDKException; 
use Facebook\Helpers\FacebookJavaScriptHelper; 
use Facebook\Helpers\FacebookRedirectLoginHelper; 
Class Facebook 
{ 
    /** 
     * @var FB 
     */ 
    private $fb; 
    /** 
     * @var FacebookRedirectLoginHelper|FacebookJavaScriptHelper 
     */ 
    private $helper; 
 
    /** 
     * Facebook constructor. 
     */ 
    public function __construct(){ 
        // Load fb config 
        $this->load->config('facebook'); 
        // Load required libraries and helpers 
        $this->load->library('session'); 
        $this->load->helper('url'); 
        if (!isset($this->fb)){ 
            $this->fb = new FB([ 
                'app_id'                => $this->config->item('facebook_app_id'), 
                'app_secret'            => $this->config->item('facebook_app_secret'), 
                'default_graph_version' => $this->config->item('facebook_graph_version') 
            ]); 
        } 
        // Load correct helper depending on login type 
        // set in the config file 
        switch ($this->config->item('facebook_login_type')){ 
            case 'js': 
                $this->helper = $this->fb->getJavaScriptHelper(); 
                break; 
            case 'canvas': 
                $this->helper = $this->fb->getCanvasHelper(); 
                break; 
            case 'page_tab': 
                $this->helper = $this->fb->getPageTabHelper(); 
                break; 
            case 'web': 
                $this->helper = $this->fb->getRedirectLoginHelper(); 
                break; 
        } 
        if ($this->config->item('facebook_auth_on_load') === TRUE){ 
            // Try and authenticate the user right away (get valid access token) 
            $this->authenticate(); 
        } 
    } 
     
    /** 
     * @return FB 
     */ 
    public function object(){ 
        return $this->fb; 
    } 
     
    /** 
     * Check whether the user is logged in. 
     * by access token 
     * 
     * @return mixed|boolean 
     */ 
    public function is_authenticated(){ 
        $access_token = $this->authenticate(); 
        if(isset($access_token)){ 
            return $access_token; 
        } 
        return false; 
    } 
     
    /** 
     * Do Graph request 
     * 
     * @param       $method 
     * @param       $endpoint 
     * @param array $params 
     * @param null  $access_token 
     * 
     * @return array 
     */ 
    public function request($method, $endpoint, $params = [], $access_token = null){ 
        try{ 
            $response = $this->fb->{strtolower($method)}($endpoint, $params, $access_token); 
            return $response->getDecodedBody(); 
        }catch(FacebookResponseException $e){ 
            return $this->logError($e->getCode(), $e->getMessage()); 
        }catch (FacebookSDKException $e){ 
            return $this->logError($e->getCode(), $e->getMessage()); 
        } 
    } 
     
    /** 
     * Generate Facebook login url for web 
     * 
     * @return  string 
     */ 
    public function login_url(){ 
        // Login type must be web, else return empty string 
        if($this->config->item('facebook_login_type') != 'web'){ 
            return ''; 
        } 
        // Get login url 
        return $this->helper->getLoginUrl( 
            base_url() . $this->config->item('facebook_login_redirect_url'), 
            $this->config->item('facebook_permissions') 
        ); 
    } 
     
    /** 
     * Generate Facebook logout url for web 
     * 
     * @return string 
     */ 
    public function logout_url(){ 
        // Login type must be web, else return empty string 
        if($this->config->item('facebook_login_type') != 'web'){ 
            return ''; 
        } 
        // Get logout url 
        return $this->helper->getLogoutUrl( 
            $this->get_access_token(), 
            base_url() . $this->config->item('facebook_logout_redirect_url') 
        ); 
    } 
     
    /** 
     * Destroy local Facebook session 
     */ 
    public function destroy_session(){ 
        $this->session->unset_userdata('fb_access_token'); 
    } 
     
    /** 
     * Get a new access token from Facebook 
     * 
     * @return array|AccessToken|null|object|void 
     */ 
    private function authenticate(){ 
        $access_token = $this->get_access_token(); 
        if($access_token && $this->get_expire_time() > (time() + 30) || $access_token && !$this->get_expire_time()){ 
            $this->fb->setDefaultAccessToken($access_token); 
            return $access_token; 
        } 
        // If we did not have a stored access token or if it has expired, try get a new access token 
        if(!$access_token){ 
            try{ 
                $access_token = $this->helper->getAccessToken(); 
            }catch (FacebookSDKException $e){ 
                $this->logError($e->getCode(), $e->getMessage()); 
                return null; 
            } 
            // If we got a session we need to exchange it for a long lived session. 
            if(isset($access_token)){ 
                $access_token = $this->long_lived_token($access_token); 
                $this->set_expire_time($access_token->getExpiresAt()); 
                $this->set_access_token($access_token); 
                $this->fb->setDefaultAccessToken($access_token); 
                return $access_token; 
            } 
        } 
        // Collect errors if any when using web redirect based login 
        if($this->config->item('facebook_login_type') === 'web'){ 
            if($this->helper->getError()){ 
                // Collect error data 
                $error = array( 
                    'error'             => $this->helper->getError(), 
                    'error_code'        => $this->helper->getErrorCode(), 
                    'error_reason'      => $this->helper->getErrorReason(), 
                    'error_description' => $this->helper->getErrorDescription() 
                ); 
                return $error; 
            } 
        } 
        return $access_token; 
    } 
     
    /** 
     * Exchange short lived token for a long lived token 
     * 
     * @param AccessToken $access_token 
     * 
     * @return AccessToken|null 
     */ 
    private function long_lived_token(AccessToken $access_token){ 
        if(!$access_token->isLongLived()){ 
            $oauth2_client = $this->fb->getOAuth2Client(); 
            try{ 
                return $oauth2_client->getLongLivedAccessToken($access_token); 
            }catch (FacebookSDKException $e){ 
                $this->logError($e->getCode(), $e->getMessage()); 
                return null; 
            } 
        } 
        return $access_token; 
    } 
     
    /** 
     * Get stored access token 
     * 
     * @return mixed 
     */ 
    private function get_access_token(){ 
        return $this->session->userdata('fb_access_token'); 
    } 
     
    /** 
     * Store access token 
     * 
     * @param AccessToken $access_token 
     */ 
    private function set_access_token(AccessToken $access_token){ 
        $this->session->set_userdata('fb_access_token', $access_token->getValue()); 
    } 
     
    /** 
     * @return mixed 
     */ 
    private function get_expire_time(){ 
        return $this->session->userdata('fb_expire'); 
    } 
     
    /** 
     * @param DateTime $time 
     */ 
    private function set_expire_time(DateTime $time = null){ 
        if ($time) { 
            $this->session->set_userdata('fb_expire', $time->getTimestamp()); 
        } 
    } 
     
    /** 
     * @param $code 
     * @param $message 
     * 
     * @return array 
     */ 
    private function logError($code, $message){ 
        log_message('error', '[FACEBOOK PHP SDK] code: ' . $code.' | message: '.$message); 
        return ['error' => $code, 'message' => $message]; 
    } 
     
    /** 
     * Enables the use of CI super-global without having to define an extra variable. 
     * 
     * @param $var 
     * 
     * @return mixed 
     */ 
    public function __get($var){ 
        return get_instance()->$var; 
    } 
}

Controllers (application/controllers/)

User_authentication.php
The User_Authentication controller handles the Facebook API authentication process using PHP SDK and Graph API.

• __construct() – Loads the Facebook library and User model to handle the OAuth and database related works.
• index() –
  • Initially, generate the authentication URL is generated using login_url() method of the Facebook library.
  • If the user authenticates with their Facebook account,
    • Retrieve the user’s profile data from Facebook using request() method of the Facebook library.
    • Insert/Update account data in the database using checkUser() function of the User model.
    • Store the user’s account info in the SESSION.
    • Generate logout URL using logout_url() method of the Facebook library.
    • Pass the user’s account data (for the authenticated user) or OAuth URL (for the non-authenticated user) to the view.
• logout() – If the user wishes to log out from their Facebook account, this method is loaded.
  • Remove local Facebook SESSION.
  • Remove user data from SESSION.
  • Redirect the user to the login page.

<?php 
defined('BASEPATH') OR exit('No direct script access allowed'); 
 
class User_Authentication extends CI_Controller { 
    function __construct() { 
        parent::__construct(); 
         
        // Load facebook oauth library 
        $this->load->library('facebook'); 
         
        // Load user model 
        $this->load->model('user'); 
    } 
     
    public function index(){ 
        $userData = array(); 
         
        // Authenticate user with facebook 
        if($this->facebook->is_authenticated()){ 
            // Get user info from facebook 
            $fbUser = $this->facebook->request('get', '/me?fields=id,first_name,last_name,email,link,gender,picture'); 
 
            // Preparing data for database insertion 
            $userData['oauth_provider'] = 'facebook'; 
            $userData['oauth_uid']    = !empty($fbUser['id'])?$fbUser['id']:'';; 
            $userData['first_name']    = !empty($fbUser['first_name'])?$fbUser['first_name']:''; 
            $userData['last_name']    = !empty($fbUser['last_name'])?$fbUser['last_name']:''; 
            $userData['email']        = !empty($fbUser['email'])?$fbUser['email']:''; 
            $userData['gender']        = !empty($fbUser['gender'])?$fbUser['gender']:''; 
            $userData['picture']    = !empty($fbUser['picture']['data']['url'])?$fbUser['picture']['data']['url']:''; 
            $userData['link']        = !empty($fbUser['link'])?$fbUser['link']:'https://www.facebook.com/'; 
             
            // Insert or update user data to the database 
            $userID = $this->user->checkUser($userData); 
             
            // Check user data insert or update status 
            if(!empty($userID)){ 
                $data['userData'] = $userData; 
                 
                // Store the user profile info into session 
                $this->session->set_userdata('userData', $userData); 
            }else{ 
               $data['userData'] = array(); 
            } 
             
            // Facebook logout URL 
            $data['logoutURL'] = $this->facebook->logout_url(); 
        }else{ 
            // Facebook authentication url 
            $data['authURL'] =  $this->facebook->login_url(); 
        } 
         
        // Load login/profile view 
        $this->load->view('user_authentication/index',$data); 
    } 
 
    public function logout() { 
        // Remove local Facebook session 
        $this->facebook->destroy_session(); 
        // Remove user data from session 
        $this->session->unset_userdata('userData'); 
        // Redirect to login page 
        redirect('user_authentication'); 
    } 
}

Models (application/models/)

User.php
The User model handles the database related operations (insert and update).

• __construct() – Define the database table name.
• checkUser() – Insert or update the user profile information based on the OAuth provider and ID. Returns the row ID on success, and FALSE on error.

<?php
defined('BASEPATH') OR exit('No direct script access allowed');

class User extends CI_Model {
    function __construct() {
        $this->tableName = 'users';
        $this->primaryKey = 'id';
    }
    
    /*
     * Insert / Update facebook profile data into the database
     * @param array the data for inserting into the table
     */
    public function checkUser($userData = array()){
        if(!empty($userData)){
            //check whether user data already exists in database with same oauth info
            $this->db->select($this->primaryKey);
            $this->db->from($this->tableName);
            $this->db->where(array('oauth_provider'=>$userData['oauth_provider'], 'oauth_uid'=>$userData['oauth_uid']));
            $prevQuery = $this->db->get();
            $prevCheck = $prevQuery->num_rows();
            
            if($prevCheck > 0){
                $prevResult = $prevQuery->row_array();
                
                //update user data
                $userData['modified'] = date("Y-m-d H:i:s");
                $update = $this->db->update($this->tableName, $userData, array('id' => $prevResult['id']));
                
                //get user ID
                $userID = $prevResult['id'];
            }else{
                //insert user data
                $userData['created']  = date("Y-m-d H:i:s");
                $userData['modified'] = date("Y-m-d H:i:s");
                $insert = $this->db->insert($this->tableName, $userData);
                
                //get user ID
                $userID = $this->db->insert_id();
            }
        }
        
        //return user ID
        return $userID?$userID:FALSE;
    }
}

Views (application/views/)

user_authentication/index.php
If the user already logged in with their Facebook account, the profile details are displayed. Otherwise, Sign-in with Facebook button is shown to the user.

<!-- Display login button / Facebook profile information -->
<?php if(!empty($authURL)){ ?>
	<h2>CodeIgniter Facebook Login</h2>
    <a href="<?php echo $authURL; ?>"><img src="<?php echo base_url('assets/images/fb-login-btn.png'); ?>"></a>
<?php }else{ ?>
    <h2>Facebook Profile Details</h2>
    <div class="ac-data">
        <img src="<?php echo $userData['picture']; ?>"/>
        <p><b>Facebook ID:</b> <?php echo $userData['oauth_uid']; ?></p>
        <p><b>Name:</b> <?php echo $userData['first_name'].' '.$userData['last_name']; ?></p>
        <p><b>Email:</b> <?php echo $userData['email']; ?></p>
        <p><b>Gender:</b> <?php echo $userData['gender']; ?></p>
        <p><b>Logged in with:</b> Facebook</p>
        <p><b>Profile Link:</b> <a href="<?php echo $userData['link']; ?>" target="_blank">Click to visit Facebook page</a></p>
        <p><b>Logout from <a href="<?php echo $logoutURL; ?>">Facebook</a></p>
    </div>
<?php } ?>

Test the Facebook Login in Codeigniter

After the code implementation, now it’s time to test the Facebook Login in CodeIgniter application. Open the application OAuth URL (https://www.example.com/user_authentication/) in the browser.

• The Login with the Facebook button will appear, click on it.
• You will be redirected to the Facebook page for Authentication.
• After successful authentication, you will be redirected back to the web application and the Facebook account details will be displayed on the web page.
• Also, Facebook profile data will be stored in the database.

Login with Facebook without Page Refresh using JavaScript SDK

Conclusion

We have tried to make the Facebook login integration easier for the CodeIgniter web application. Hope! you can easily implement Facebook login system in CodeIgniter using our example code. The example code uses the latest version of Facebook SDK, so, Facebook PHP SDK v5 library is required. You don’t need to download the SDK library separately, all the required files are included in our source code (including the PHP SDK v5 for CodeIgniter).