Experiments with SwiftUI view initialization creation

SwiftUIPropertyRecreation.swift

import SwiftUI

final class SomeClass {

    static var instanceNr: Int = 0

    init(_ owner: String) {
        SomeClass.instanceNr += 1
        print("Created new instance (nr. \(SomeClass.instanceNr)) for owner \(owner)")
    }
}


struct ContentView: View {

    let someClass = SomeClass("mainView")
    @State var counter: Int = 0

    var body: some View {
        VStack {
            Button(action: { // tapping this button recreates SubView and with it subSomeInstance
                self.counter += 1
            }) {
                Text("Main counter \(counter)")
            }
            SubView()
            Text("Instances of SomeClass \(SomeClass.instanceNr)")
        }
    }
}

struct SubView: View {

    private let subSomeInstance = SomeClass("subview")
    @State private var counter: Int = 0

    var body: some View {
        Button(action: { // tapping this button doesn't recreate subSomeInstance
            self.counter += 1
        }) {
            Text("Sub counter \(counter)")
        }
    }
}

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