Yii CModel:hasErrors方法

CModel::hasErrors方法,竟然在authenticate时也能用,不是应该在所有的rules都验证完之后才能获取吗?后来经过测试和查看源码,才知道,hasError并不是一并获取,而是根据当前已经验证过的rule实时获取,也就是说,假如有a,b,c,d四条rule,那么如果crule需要一个回调函数去验证(如array('password', 'authenticate')),而且drule一定会验证出错误,那在authenticate方法中,是获取不到第d条rule验出的错误的.在回调函数中调用CModel:hasErrors时,一定要注意这一点

class LoginForm extends CFormModel{
..............
    public function rules()
    {
        return array(
            // username and password are required
            array('username, password', 'required'),
            array('password', 'length', 'min'=>6),
            // rememberMe needs to be a boolean
            array('rememberMe', 'boolean'),
            // password needs to be authenticated
            array('password', 'authenticate'),
        );
    }
    /**
     * Authenticates the password.
     * This is the 'authenticate' validator as declared in rules().
     */
    public function authenticate($attribute,$params)
    {
        if(!$this->hasErrors())
        {
            $this->_identity=new UserIdentity($this->username,$this->password);
            if(!$this->_identity->authenticate())
                $this->addError('password','邮箱或密码错误.');
        }
    }

CModel