内容简介：In case you are working with the ES6+ class system, you most likely want to use configs (properties) for your own classes. Since the class system is still lacking to define these inline, you could use the constructor:You will most likely notice right away,
In case you are working with the ES6+ class system, you most likely want to use configs (properties) for your own classes. Since the class system is still lacking to define these inline, you could use the constructor:
You will most likely notice right away, that this approach is not really helpful, since you have no change listeners for your class configs. Defining the properties via get & set can help with this:
Both class definitions are pretty similar, but the 2nd one allows us to use myInstance.a = 2; for automatically triggering the setter. As a design pattern, saving the content of each property inside a underscore prefixed version does make sense (e.g. a => _a). You could add more logic into each setter, but as soon as you want to extend your own classes again, this will cause problems. So calling new methods which you can extend or override makes more sense:
Passing the new & the old value makes a lot of sense. As a design pattern, I recommend to use method names like afterSetMyConfig(). In case you want to extend your class now, you can override afterSetA and use the superclass call (super.afterSetA(value, oldValue);) as needed.
In case you are using the neo.mjs framework , you can shorten this code quite a bit:
applyClassConfig will generate something similar to the previous version, with the difference that you can change the default values for your properties more easily when extending classes.
Chicken or egg?
You might have noticed that afterSetA() is using this.b internally. You could flip the order of a_ & b_ inside the getConfig() method to change the order in which the configs do get applied. Since afterSetB() is using this.a internally, we ended up with a circular reference , so we can not solve this issue just using the config order. In neo.mjs, i solved it like this:
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持 码农网
猜你喜欢:
本站部分资源来源于网络，本站转载出于传递更多信息之目的，版权归原作者或者来源机构所有，如转载稿涉及版权问题，请联系我们。
《Hello Ruby：儿童编程大冒险》（平装）
（芬兰）琳达·刘卡斯 / 窝牛妈 / 浙江人民美术出版社 / 2018
快来认识Ruby——一个想象力丰富，喜欢解决难题的女生。Ruby认识了一群新朋友：聪明的雪豹、友好的狐狸、忙碌的机器人等等。这本书以讲故事的方式向孩子们介绍了基础的计算思维，比如拆分问题，制定分步计划，寻找规律，打破思维定势等等；之后，通过一系列鼓励探索和创造的练习和活动，孩子们对这些关乎编程核心问题的基本概念有了进一步的理解。一起来看看 《《Hello Ruby：儿童编程大冒险》（平装）》 这本书的介绍吧!
