View refreshing not triggered when ObservableObject is inherited in SwiftUI

Question

ContentView2 view is not refreshed when model.value changes, if Model conforms to ObservableObject directly instead of in

Answer 1

Here is working variant of your example. See that to be able to work, not only chaining the publishers is required, but at least one Published property. So or so, it could help in some scenario.

import SwiftUI

class SuperModel: ObservableObject {
    // this is workaround but not real trouble.
    // without any value in supermodel there is no real usage of SuperModel at all
    @Published var superFlag = false
}

class Model: SuperModel {
    @Published var value = ""
    override init() {
        super.init()
        _ = self.objectWillChange.append(super.objectWillChange)
    }
}

struct ContentView: View {

    @ObservedObject var model = Model()

    var body: some View {
        VStack {
            Text(model.value)
            Button("change value") {
                self.model.value = "\(Int.random(in: 1...10))"
            }
        }

    }
}
struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}

changing the code to

var body: some View {
        VStack {
            Text(model.value)
            Button("change value") {
                self.model.value = "\(Int.random(in: 1...10))"
            }
            Text(model.superFlag.description)
            Button("change super flag") {
                self.model.superFlag.toggle()
            }
        }

    }

you can see how to use even your supermodel at the same time