How to use sentMessage with subclass?

[onmyway133]

Hi, I'm trying to use sentMessage with subclass. I have a class called

class ListController: UIViewController {
  override func viewDidAppear(_ animated: Bool) {
    super.viewDidAppear(animated)
    // THIS IS AN OVERRIDDEN METHOD
  }

  func hello() {
    // THIS IS A METHOD FROM SUBCLASS
  }
}

And I use sentMessage

let list = ListController()

list.rx.sentMessage(#selector(ListController.hello)).subscribe(onNext: {
  print($0)
})

list.rx.sentMessage(#selector(ListController.viewDidAppear(_:))).subscribe(onNext: {
  print($0)
})

list.viewDidAppear(true)
list.hello()

I see that subscribe is not called at all. It seems that sentMessage does not work for subclass if

• it overrides the method
• it introduces a new method

What I'm trying to do is onmyway133/blog#55. I've just read this #308 so maybe there's some clues there.

I don't like swizzling, just want to see how it works with this case

[tarunon]

@onmyway133 Hello, I think this problem is caused difference of method invocation between Swift and Objective-C.
Actually, NSObject.rx.sentMessage and NSObject.rx.methodInvoked is based on method swizzling, Swift method invocation based v-table and it's not affected by method swizzling.
If you want to use objc_msgSend way in swift, you can use dynamic modifier on your function.

class ListController: UIViewController {
  override dynamic func viewDidAppear(_ animated: Bool) {
    super.viewDidAppear(animated)
    // THIS IS AN OVERRIDDEN METHOD
  }

  dynamic func hello() {
    // THIS IS A METHOD FROM SUBCLASS
  }
}

But in my opinion, it's not good that using NSObject.rx.sentMessage and NSObject.rx.methodInvoked a lot.