import SwiftUI

// Capítulo 4: Creando nuestros propios Property Wrappers

@propertyWrapper
struct UpperCase {
    private(set) var value: String
    
    var wrappedValue: String {
        get { value }
        set { value = newValue.uppercased() }
    }
    
    init(wrappedValue: String) {
        self.value = wrappedValue.uppercased()
    }
}

struct User {
    @UpperCase var name: String
}

struct UserView: View {
    @ObservedObject var user: User
    
    var body: some View {
        VStack {
            Text("Hello, \(user.name)")
            TextField("Enter your name", text: $user.name)
        }
    }
}

struct ContentView: View {
     var body: some View {
       UserView(user: User(name: "John Doe"))
     }
}