@Binding Bool variable inside SwiftUI component does not fire when variable is true

Question

So I had something like this code

struct MyComponent: View {
   @Binding var isShowing: Bool
   
   var body: some View {
       Text("sample")
          .offset("")
          .offset(y: isShowing ? -100: 0) //values just for example
          .animation(.easeInOut, value: isShowing)
   }
}

I wanted to add a didShow callback whenever isShowing is being true. The problem I got is this code

@Binding var isShowing: Bool {
   didSet {
      didShow()
   }
 }

only fires when isShowing is false.

I was stucked here for days.

Answer 1

What worked for me is I made an empty View which performs callback inserted on its onAppear and onDisappear

struct CallbackView: View {
  let onAppear: (()->())?
  let onDisappear: (()->())?

  init(onAppear: (()->())? = nil, onDisappear: (()->())? = nil) {
      self.onAppear = onAppear
      self.onDisappear = onDisappear
  }

  var body: some View {
      VStack {
         Spacer()
      }
      .frame(width: 0, height: 0)
      .onAppear {
        self.onAppear?()
      }
      .onDisappear {
        self.onDisappear?()
      }
  }

then I added it in MyComponent's body like:

if isShowing {
    CallbackView(onAppear: {
                   //.. do something
                 },
                 onDisappear: {
                   //.. do something
                 })
}

Instead of making a struct, this also works if you just make it into an internal View variable inside a View.

This may not be the best way. But it's the only one that worked for me and I'm very happy that I got out of my problem.