3使用Codeigniter登录选项（Google Plus，Facebook和直接注册）

Question

I am creating a website using codeigniter where I require 3 login options (Google+, Facebook & Direct Registration).

I am able to achieve this independently; however I am not too sure how to combine to 3 into one controller and start the session.

Here is the controller code for Facebook Login:

public function login()
{
    $this->load->model('master/user_model','User');
    $this->load->library('session');
    $this->load->library('facebook'); 

    $user = $this->facebook->getUser();

    if ($user) {
        try {
            $data['user_profile'] = $this->facebook->api('/me');
            $aData['user_profile'] = $this->User->insert_fbuser($data['user_profile']);
            $this->session->set_userdata($aData);
        } catch (FacebookApiException $e) {
            $user = null;
        }
    }else {
        $this->facebook->destroySession();
    }

    if ($user) {

        $aData['logout_url'] = site_url('logout'); // Logs off application
        // OR
        // Logs off FB!
        // $data['logout_url'] = $this->facebook->getLogoutUrl();

    } else {
        $aData['login_url'] = $this->facebook->getLoginUrl(array(
            'redirect_uri' => site_url('login'),
            'scope' => array("email") // permissions here
        ));
    }
    //$data1 = array_merge($aData, $data);
    $this->load->view(__CLASS__.'/index',$aData);

}

Thanks for your time.

Regards, Utpal