Oauth身份验证cakeHP插件

我对这个插件感到困惑。

只是复制粘贴演示，但我得到了这个错误，当我试图连接到脸书：

The page isn't redirecting properly
Firefox has detected that the server is redirecting the request for this address in a way that will never complete.

完整代码：

<?php
class ExamplesController extends AppController {
  public $components = array(
    'Auth'=> array(
      'loginAction' => array(
        'controller' => 'examples',
        'action'     => 'login'
      ),
      'loginRedirect' => array(
        'controller' => 'examples',
        'action'     => 'my_account'
      ),
      'authError' => 'Did you really think you are allowed to see that?',
      'authenticate' => array(
        'FacebookAuth.Facebook' => array(
          'fields' => array(
            'username' => 'email',
                'password' => 'password'
          )
        )
      )
    )
  );
    public function index() {
    }
  public function beforeFilter()
  {
    parent::beforeFilter();
    $this->Auth->authenticate['FacebookAuth.Facebook']['application'] = array(
      'id'     => Configure::read('facebook.app_id'),
      'secret' => Configure::read('facebook.app_secret')
    );
    $this->Auth->allowedActions = array_merge($this->Auth->allowedActions, array('login'));
  }
  public function login()
  {
    if (!$this->Auth->login()) {
      /**
       * Get config for Facebook redirect
       */
      $clientId    = Configure::read('facebook.app_id');
      $permissions = implode(',', Configure::read('facebook.permissions'));
      $redirect    = Router::url(false, true);
      $csrfToken   = CakeSession::read('FacebookAuthCSRF');
      $this->redirect(Configure::read('facebook.oauth_dialg_url') . '?client_id=' . $clientId . '&redirect_uri=' . $redirect . '&scope=' . $permissions . '&state=' . $csrfToken);
    } else {
      $this->redirect(array('action' => 'my_account'));
    }
  }
  public function my_account()
  {
    var_dump($this->Auth->user());
    die();
  }
}

挑战在于弄清楚如何让插件正常工作。

更新：好的，我有这个网址（感谢elliot）：

http://someHost/?client_id=4003xx16796&redirect_uri=http://localhost/cake/users/login&scope=email&state=f96419881df77cdc689e6c43c131cf3b

现在，该如何处理url？基本上是下一步。我只有一个loggin按钮，点击后可以更改url，就像上面的演示一样，但没有任何操作。响应为空。

我已经读过了。