adding log in using facebook option in registration form - php

Question

I have a registration form in my site,where the users submits their personal details such as name,email id,dob,and mobile number to be stored in my database. Now I am in the idea to include the connect with facebook button,,by using that link,the user can provide their details by logging into their account. those details can be stored in my database. my expectation looks like this image..help me to implement this

Answer 1

First, you need to decide whether you want to use PHP or JavaScript for Facebook's SDK. Then, download the SDK from:
https://developers.facebook.com/docs/facebook-login/login-flow-for-web/v2.2
Here's a "Getting started" guide for PHP:
https://developers.facebook.com/docs/php/gettingstarted/4.0.0
And here's the same kind of guide for JavaScript:
https://developers.facebook.com/docs/javascript
Here's a part of my code for Facebook Login written with PHP. Note that I'm using CodeIgniter as a framwork for my project:
public function registerWithFacebook()
{
try {
// Proceed knowing you have a logged in user who's authenticated
$facebook_user_data = $this->facebook->get_user();
} catch (FacebookApiException $e) {
$user = null;
print_r($e);
return false;
}
// if we don't have the facebook-user array variable, leave the method
if (!$facebook_user_data) {
return false;
}
// If we can't get the email, leave the method
if(!$facebook_user_data['email']) {
return false;
}
// If user is already registered with Facebook, start sessions and redirect user to app home page (exit the method at this point)
if ($this->facebook_model->facebookUserIdExistsAlreadyInDatabase($facebook_user_data)) {
$session = $this->user_model->getUserInfo($facebook_user_data['id']);
$data = array(
'user_id' => $session['user_id'],
'name' => $session['name'],
'email' => $session['email'],
'profilepic' => $session['profilepic'],
'loggedin' => true,
);
$this->session->set_userdata($data);
redirect(base_url().'home');
exit();
}
// Generate password for new user since you can't get the password from Facebook (obviously)
$generated_password = random_string('alnum', 8);
$data = [
'email' => $facebook_user_data['email'],
'name' => $facebook_user_data['name'],
'password' => $this->phpass->hash($generated_password),
'profilepic' => 'https://graph.facebook.com/'.$facebook_user_data['id'].'/picture?width=160&height=160',
'user_facebook_id' => $facebook_user_data['id'],
];
// Insert data to your database
$new_user = $this->facebook_model->add_facebook_user($data);
// If new user's data was saved successfully to database, start sessions and redirect user
if($new_user) {
$session = $this->user_model->getUserInfo($facebook_user_data['id']);
$data = array(
'user_id' => $session['user_id'],
'name' => $session['name'],
'email' => $session['email'],
'profilepic' => 'https://graph.facebook.com/'.$facebook_user_data['id'].'/picture?width=160&height=160',
'loggedin' => true,
);
$this->session->set_userdata($data);
redirect(base_url().'home');
}
}