@qiangxue Agree and one thing. I think we need standartize cancel value to `false`, to avoid Yii 1.1.x situation where we can cancel some by `null`, `false`, `''`, `array()`. This will lead to cleaner code and not confuse users. They will always know that `false` = no render, no attribute, ... . If you like this cancel standartize approach it should be documented in code style.