swift - How to wrap protocol with optional methods?

Question

Task is simple: I need to create wrapper that delegates everything to wrapped object. Only the type of wrapped object is a protocol that contains optional methods. My wrapper is to implement the same protocol.

What do I do about optional methods? I can:

1. I can implement them in my wrapper. But if they are not implemented by the object that gets wrapped what do I return from this implementations?
2. Not implement them. In that case the wrapper object will not provide some of functionality of the wrapped object which I don't want.

Are there any better options? Please note that I am working in Swift.

Answer 1

如果您使用可选方法，您将使用 Objective-C 运行时。这意味着您可以查询对象是否响应可选方法，这里有更好的解释。

如果您是 Objective-C 运行时的新手，您可以在Objective-C 运行时编程指南中阅读更多相关信息。

我认为包装器应该在运行时检查实现，如果缺少，那么应该在调用这些可选方法之一时返回某种指示符，可能是一个布尔值。