google-oauth library working in session in MVC PHP

Question

Hi I would like to learn something from here, basically I want the access of my system to be in google account somehow I manage to do the following

• get client id, redirect uris, secret keys
• authentication from google account
• get token

but I i felt I was doing wrong all in some part, this is the Oauth2callback

class Oauth2callback extends CI_Controller {


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

        $this->load->helper('url');
        $this->load->library('session');
        require_once APPPATH.'libraries/Google/Client.php';
        session_start();


    }

    public function index()
    {


        $client_id = $this->config->item('client_id');
        $client_secret = $this->config->item('client_secret');
        $redirect_uri = $this->config->item('redirect_uri');

        $client = new Google_Client();
        $client->setClientId($client_id);
        $client->setClientSecret($client_secret);
        $client->setRedirectUri($redirect_uri);
        $client->addScope("https://www.googleapis.com/auth/userinfo.email");
        $client->addScope("https://www.googleapis.com/auth/userinfo.profile");

        if (isset($_GET['code'])) {
            $client->authenticate($_GET['code']);
            $_SESSION['access_token'] = $client->getAccessToken();
            $redirect = 'http://' . $_SERVER['HTTP_HOST'] . $_SERVER['PHP_SELF'];

            header('Location: ' . filter_var($redirect, FILTER_SANITIZE_URL));
        }

        if (isset($_SESSION['access_token']) && $_SESSION['access_token']) {
            $client->setAccessToken($_SESSION['access_token']);
        } else {
            $authUrl = $client->createAuthUrl();
        }

        if ($client->getAccessToken()) {
            $_SESSION['access_token'] = $client->getAccessToken();


        }


        if(isset($authUrl)) {
            header('location:'. base_url());
        }else{
            header('location:'. base_url().'dashboard');
        }
    }

but this is my index controller the Login it only has button sign in with Google

class Login extends CI_Controller {


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

        $this->load->helper('url');
        $this->load->library('session');
        require_once APPPATH.'libraries/Google/Client.php';
        session_start();
    }

    public function index()
    {
        //$this->checkSession();
        $client_id = $this->config->item('client_id');
        $client_secret = $this->config->item('client_secret');
        $redirect_uri = $this->config->item('redirect_uri');

        $client = new Google_Client();
        $client->setClientId($client_id);
        $client->setClientSecret($client_secret);
        $client->setRedirectUri($redirect_uri);
        $client->addScope("https://www.googleapis.com/auth/userinfo.email");
        $client->addScope("https://www.googleapis.com/auth/userinfo.profile");

            $authUrl = $this->data['authUrl'] = $client->createAuthUrl();
            $this->load->view('login/index.php',$this->data);
            $this->load->view('template/pre_footer');
            $this->load->view('template/footer');


    }
}

what would be the right process of this using MVC PHP I need to do the ff. :
A. click button sign in to google
B. get token and save it to session
C. used the token to my entire system (in every controller)

what I have right now is A & B but the C i totally don't know what to do.

could anyone help me with this. any suggestion comment is well appreciated. thanks in advance.

Answer 1

The code you have might be a bit confusing because it handles authorization url, redirect to Google, callback to your site, and save the access token at the same time.

When it comes to use the access token to perform authenticated call to the api, it's much simpler. If you have a valid access token stored in you session, you can really use it anywhere to initialize the Google Application, this way:

// client
$client = new Google_Client();
$client->setApplicationName('Google Application');
$client->setClientId($clientId);
$client->setClientSecret($clientSecret);
$client->setRedirectUri($redirectUri);

// token
$client->setAccessToken($token);

Now if you want this to be available across several controllers, the most appropriate way in CodeIgniter would be to create a new library wrapping the code above.

The advantage of using a library is that they can be auto-loaded in CodeIgniter config, and are easily accessible anywhere in your code.

Example library:

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

class Someclass {

    private $client;

    public function __construct()
    {
        ... 

        // client
        $client = new Google_Client();
        $this->client->setApplicationName('Google Application');
        $this->client->setClientId($clientId);
        $this->client->setClientSecret($clientSecret);
        $this->client->setRedirectUri($redirectUri);

        // token
        $this->client->setAccessToken($token);
    }
}

?>

Then you just have to do this to use it in your controller:

 $this->load->library('someclass');

You could also create shortcuts to specific APIs. For example, if you wanted a quick access to Google Analytics API, you could do this:

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

class Someclass {

    private $client;

    public function __construct()
    {
        ... 

        // client
        $client = new Google_Client();
        $this->client->setApplicationName('Google Application');
        $this->client->setClientId($clientId);
        $this->client->setClientSecret($clientSecret);
        $this->client->setRedirectUri($redirectUri);

        // token
        $this->client->setAccessToken($token);
    }

    public function analytics()
    {
        return new Google_Service_Analytics($this->client);
    }
}

?>

And then use it this way in your controller:

 $this->load->library('someclass');
 $this->someclass->analytics();

Learn more about CodeIgniter libraries:

http://ellislab.com/codeigniter/user-guide/general/creating_libraries.html