Yii登录用户类型未写入

我刚刚用yii登录。在我的登录表中有一个"usertype"列，所以为了检查它是否正常工作，我在代码中放入了一个文件编写器，但每次代码运行时都不会被写入（忘记用户类型，甚至不是字符串）。以下是代码

组件/用户标识

<?php
class UserIdentity extends CUserIdentity
{
    private $_id;
public function authenticate()
{

            $user = Trackaccountusers::model()->findByAttributes(array('username'=>$this->username));
            if ($user===null) { // No user found!
            $this->errorCode=self::ERROR_USERNAME_INVALID;
            } else if ($user->password !== ($this->password) ) { // Invalid password!
            $this->errorCode=self::ERROR_PASSWORD_INVALID;
            } else { // Okay!
            $this->errorCode=self::ERROR_NONE;
            // Store the role in a session:
            $this->setState('usertype', $user->usertype);
            $file = "log.txt";
            $write = ("time_s ".$user->usertype."'n");//
            file_put_contents($file, $write, FILE_APPEND);
            //$this->_id = $user->id;
            }
            return !$this->errorCode;
}
            public function getId()
            {
            return $this->_id;
            }

}