问Zend :将值从控制器传递到视图时不完整的对象错误

EN

<?php echo $this->current_user->get_avatar_url(); ?>

public function get_avatar_url()
{
    return !empty($this->avatar) ? $this->avatar : $this->fb_userid != '' ? "http://graph.facebook.com/".$this->fb_userid."/picture" : "/public/images/pukie.jpg";
}

<?php
Zend_Loader::loadClass('Zend_Controller_Action');
Zend_Loader::loadClass('User');

class BaseController extends Zend_Controller_Action
{
    protected $auth;
    protected $current_user;
    protected $db;

    protected function initialize_values()
    {
        $auth = Zend_Auth::getInstance();
        if($auth->hasIdentity())
        {
            $this->current_user = $auth->getIdentity();
            $this->view->current_user = $this->current_user;
        }

        $this->db = Zend_Registry::get('dbAdapter');

        $this->view->controller_name = $this->_request->getControllerName();
        $this->view->view_name = $this->_request->getActionName();
    }
}