Login with facebook using codeigniter

In this tutorial, We are going to discuss. How to create a login system step by step using Facebook API in CodeIgniter. Here I have used the latest version facebook SDK 5 for access the users token. Follow the step by step process and Create your own facebook login API.

Live demo                 Download

Before using this script first read our latest tutorial, How to create facebook API. Because it must require for the developer for setting facebook API process.

For better understand how this code will work. Just download this script paste in your localhost. Change the facebook configuration setting. But make sure if you're running this script your app should be in developer mode,

Facebook App

You have to create an application on facebook. After creating app Facebook will provide your application app id and app secret id.

• Create a new website app
• Go App review makes it live configuration.
• Get App ID and App Key
• Download latest SDK file

Database  

Here I have created 'facebook_user' table for storing facebook user basic information like(email, name,f_id). If the same user login again no need to check every time API response. 

CREATE TABLE IF NOT EXISTS `facebook_user` (
`id` int(11) NOT NULL,
  `email` varchar(100) NOT NULL,
  `name` varchar(100) NOT NULL,
  `f_id` int(11) NOT NULL
)

Facebook SDK 5.0

Download Facebook SDK file Create new file config folder facebook.php add below code that file.

Create File Path : applications/config/facebook.php (This file contains the facebook API configuration)

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

$config['facebook_app_id']              = '**********************';
$config['facebook_app_secret']          = '**********************';
$config['facebook_login_type']          = 'web';
$config['facebook_login_redirect_url']  = 'welcome/web_login';
$config['facebook_logout_redirect_url'] = 'welcome/logout';
$config['facebook_permissions']         = array('public_profile', 'publish_actions', 'email');
$config['facebook_graph_version']       = 'v2.6';
$config['facebook_auth_on_load']        = TRUE;

Controller (facebook login welcome home page)

Create a new controller for accessing login code. Here I have created a welcome controller.

Path : applications/controllers/welcome.php

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

class welcome extends CI_Controller {

    public function __construct()
    {
        parent::__construct();

        // Load library and url helper
        $this->load->library('facebook');
        $this->load->helper('url');
        $this->load->model('users_model','users'); 

    }

    // ------------------------------------------------------------------------

    /**
     * Index page
     */
    public function index()
    {
        $this->load->view('login');
    }

    // ------------------------------------------------------------------------

    /**
     * Web redirect login example page
     */
    public function web_login()
    {
        $data['user'] = array();

        // Check if user is logged in
        if ($this->facebook->is_authenticated())
        {
            // User logged in, get user details
            $user = $this->facebook->request('get', '/me?fields=id,name,
                email,birthday,gender,picture');
            if (!isset($user['error']))
            {
                $data['user'] = $user;
                  $user_information  = array(
                    'name'    => $user["name"],
                    'email'   => $user["email"],
                    'gender'  => $user["gender"],
                    'birthday' => date("Y-m-d",strtotime($user['birthday'])),
                    'log_mode' => 'facebook'
                );
                echo '<pre>'; print_r($user); exit;  
            }

        }
        else 
        {
            echo 'We are unable fetch your facebook information.'; exit;
        }

        // display view
    }

    // ------------------------------------------------------------------------

    
    public function logout()
    {
        $this->facebook->destroy_session();
        redirect('welcome/index');
    }
}

Facebook email id permission

In case you didn't get any email id. Use below code.

$user = $this->facebook->api('/me'); 
           (to)
$user = $this->facebook->api('/me?fields=email,first_name,last_name');

View

Create login.php in view folder add below code.
Path: applications/views/login.php

<body>
<div id="container">
    <h1>Login with facebook</h1>
    <div id="body"> 
    <h2>Welcome to home page</h2>   
    <a href="<?php echo $this->facebook->login_url(); ?>">

     <img src="<?php echo base_url(); ?>resource/images/facebook.png">
    </div>
</div>
</body>

* Remove index.php from your URL sometimes it makes the problem.

http://www.mostlikers.com/2015/05/codeigniter-remove-indexphp-in-url.html

"Once you replace negative thoughts with positive ones, you'll start having positive results."
                                             
                                         - Willie Nelson