如何避免在RX中使用主题 [英] How to avoid the use of Subjects in RX

问题描述

所以我一直读到所有使用Subject<T>都是不好的"的说法-我有点同意这个推理.

So I keep reading everywhere that use of Subject<T> is "bad" - and I kind of agree with the reasoning.

但是，我正在尝试避免使用它的最佳方法，并举一个例子.

However, I am trying to think of the best way to avoid using it and have an example.

当前，我为持久性配置类提供了一个抽象类，该类上具有受保护的Save()方法，只要更改属性就可以持久化该类，就会调用该方法.该消息将消息泵送到Subject<T>上，该消息通过IObservable<T>接口公开，串行化服务侦听并串行化该类.这似乎是当时实现这一目标的最明显，最简单和最快的方法.

Currently I have an abstract class for my persisted configuration classes that has a protected Save() method on it which is called whenever changing a property should persist the class. This message pumps a message onto a Subject<T> which is exposed through IObservable<T> interface which the serialisation services listens to and serialises the class. This seemed the most obvious, simple and quickest way to implement this at the time.

那么不使用Subject的RX方法是什么?我会公开一个事件并使用Observable.FromEventPattern()订阅该事件吗? -因为这似乎是更复杂的解决方法.

So what would be the RX way to do this without using a Subject? Would I instead expose an event and use Observable.FromEventPattern() to subscribe to it? - as this seems a more complex way to go about it.

推荐答案

Subject<T>的使用并没有什么坏处-必须有某种输入monad"的方式-这是学术上的说法获取IObservable<T>" .您需要从某个地方开始.

It's not so much that the use of Subject<T> is bad - there has to be some way of "entering the monad" - that's the academic way of saying "get an IObservable<T>". You need to start somewhere.

在订阅中使用Subject<T>而不是将现有的可观察对象链接在一起时，会出现更多的问题.主题应该只存在于Rx机器的边缘.

The problem with Subject<T> arises more when it's used from a subscription instead of chaining existing observables together. Subjects should just exist at the edges of your Rx machinery.

如果提供的所有入口点(例如FromEvent，FromEventPattern，FromAsync，Return，ToObservable()等)均不适合您，则使用Subject<T>是完全有效的.而且，无需为了促进使用上述方法之一而增加额外的复杂性-无论如何，其中大多数都使用主题或类似主题的构造.

If none of the provided entry points (e.g. FromEvent, FromEventPattern, FromAsync, Return, ToObservable() and so on) work for you then using Subject<T> is perfectly valid. And there's no need to add extra complexity just to facilitate using one of the above - most of them use subjects or subject-like constructs under the covers anyway.

在您的情况下，听起来像Subject<T>很好.您可能会想通过 AsObservable() 公开它为了隐藏实施细节.

In your case, sounds like Subject<T> is just fine. You might what to look at exposing it via AsObservable() in order to hide the implementation details.

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