如何使用phignurgeon spark oauth2通过codeigniter贴在墙上？

Question

我正在制作一个脚本，用于在登录后发布到Facebook的用户墙。我正在关注 https://github.com/philsturgeon/codeigniter-oauth2图书馆。 我能够成功设置登录部分。但是当我开始写入用户墙时，我没有这样做。谁能帮忙。提前致谢。

auth controller： -

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

    class Auth extends CI_Controller {

        function __construct()
        {
            parent::__construct();
            $this->load->library('layout'); 
        }

        public function login()
        {
                $this->layout->setLayout('layouts/main');
            $body_data = array();
            //$layout_data['content_body'] = $this->load->view('auth/login', $body_data, true);
            $this->layout->view('auth/login');
        }

        public function oauth($providername)
        {
            $provider = $this->config->item($providername);
            $key=$provider['key'];
            $secret=$provider['secret'];

            $this->load->helper('url');

            $this->load->spark('oauth/0.3.1');

            // Create an consumer from the config
            $consumer = $this->oauth->consumer(array(
                'key' => $key,
                'secret' => $secret,
            ));

            // Load the provider
            $provider = $this->oauth->provider($providername);

            // Create the URL to return the user to
            $callback = site_url('auth/oauth/'.$provider->name);

            if ( ! $this->input->get_post('oauth_token'))
            {
                // Add the callback URL to the consumer
                $consumer->callback($callback);

                // Get a request token for the consumer
                $token = $provider->request_token($consumer);

                // Store the token
                $this->session->set_userdata('oauth_token', base64_encode(serialize($token)));

                // Get the URL to the twitter login page
                $url = $provider->authorize($token, array(
                'oauth_callback' => $callback,
                ));

                // Send the user off to login
                redirect($url);
            }
            else
            {
                if ($this->session->userdata('oauth_token'))
                {
                // Get the token from storage
                $token = unserialize(base64_decode($this->session->userdata('oauth_token')));
                }

                if ( ! empty($token) AND $token->access_token !== $this->input->get_post('oauth_token'))
                {
                // Delete the token, it is not valid
                $this->session->unset_userdata('oauth_token');

                // Send the user back to the beginning
                exit('invalid token after coming back to site');
                }

                // Get the verifier
                $verifier = $this->input->get_post('oauth_verifier');

                // Store the verifier in the token
                $token->verifier($verifier);

                // Exchange the request token for an access token
                $token = $provider->access_token($consumer, $token);

                // We got the token, let's get some user data
                $user = $provider->get_user_info($consumer, $token);

                $this->load->model('Auth_model', 'auth');
                $this->auth->saveData($providername,$token,$user);
            }
        }


        public function oauth2($providername)
        {
            $provider = $this->config->item($providername);
            $key=$provider['key'];
            $secret=$provider['secret'];
            //$this->load->library('facebook', $fb_config);
            $this->load->spark('oauth2/0.3.1');

        $provider = $this->oauth2->provider($providername, array(
            'id' => $key,
            'secret' => $secret,
        ));

        if ( ! $this->input->get('code'))
        {
            // By sending no options it'll come back here
            $url = $provider->authorize();

            redirect($url);
        }
        else
        {
            try
            {
                // Have a go at creating an access token from the code
                $token = $provider->access($_GET['code']);

                // Use this object to try and get some user details (username, full name, etc)
                $user = $provider->get_user_info($token);

                $this->load->model('Auth_model', 'auth');
                $this->auth->saveData($providername,$token,$user);

                // Here you should use this information to A) look for a user B) help a new user sign up with existing data.
                // If you store it all in a cookie and redirect to a registration page this is crazy-simple.
                //echo "<pre>Tokens: ";


                //echo "\n\nUser Info: ";
                //var_dump($user);

            }

            catch (OAuth2_Exception $e)
            {
                show_error('That didnt work: '.$e);
            }

        }
        }

        public function logout()
        {
            $this->output->set_header("Cache-Control: no-store, no-cache, must-revalidate, no-transform, max-age=0, post-check=0, pre-check=0");
            $this->output->set_header("Pragma: no-cache");
            $this->session->userdata = array();
            $this->session->sess_destroy();
            redirect('/auth/login', 'refresh');
        }
    }
login.php
    <table width="50%" align=center>
                <tbody><tr>
                    <td width="20%"><a onclick="" href="<?=site_url(); ?>/auth/oauth2/facebook"><img src="<?=asset_url(); ?>img/facebook-login.png"></a></td>
                </tr>
            </tbody></table>


checkin.php


     <?php
        $this->auth->call("post", "me/feed", array("message" => "This is a message from the CodeIgniter Facebook Package"));
        ?>

 I tried:-

localhost/xyz/auth/login.php

Status:- successfully login
When i tried:- 

localhost/xyz/checkin.php :-

Status:- Fatal error: Call to a member function call()
Please help.