<?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 facebook 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 2.0
*/
// Include the autoloader provided in the SDK
require_once 'facebook-php-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;
}
}