observable-enum-pt2.swift

import SwiftUI

@Observable
class CounterModel {
  var count = 0
}
struct CounterView: View {
  let model: CounterModel
  var body: some View {
    Text(self.model.count.description)
    Button("Increment") { self.model.count += 1 }
  }
}
enum Enum {
  case counter(CounterModel)
}
@Observable
class ContentModel {
  var state = Enum.counter(CounterModel())
}

struct ContentView: View {
  let model = ContentModel()

  var body: some View {
    Form {
      switch self.model.state {
      case let .counter(counterModel):
        CounterView(model: counterModel)
      }

      Button("Reset") {
        self.model.state = .counter(CounterModel())
      }
    }
  }
}

#Preview {
  ContentView()
}

observable-enum.swift

import SwiftUI

@Observable
class CounterModel {
  var count = 0
}
struct CounterView: View {
  let model: CounterModel
  var body: some View {
    Text(self.model.count.description)
    Button("Increment") { self.model.count += 1 }
  }
}
enum Enum {
  case counter(CounterModel)
}

struct ContentView: View {
  @State var state = Enum.counter(CounterModel())

  var body: some View {
    Form {
      switch self.state {
      case let .counter(counterModel):
        CounterView(model: counterModel)
      }

      Button("Reset") {
        self.state = .counter(CounterModel())
      }
    }
  }
}

#Preview {
  ContentView()
}