Can't get Text to update after changing slider - swiftui

Question

I have a custom embedded View with Text and a Slider that binds to an ObservedObject. I can successfully update the binding with changing the slider but the Text does not update. For some reason, I am really struggling with getting the hang of Property Wrappers and hoping to finally get it to click.
I can easily have the text update when I'm binding the slider value to local state, but no luck with the binding.
class MyItem:ObservableObject, Codable, Identifiable {
enum CodingKeys: String, CodingKey {
case calories
}
var didChange = PassthroughSubject<Void,Never>()
var id = UUID()
var calories:Double = 0 { didSet { update() }
func update() {
didChange.send()
}
}
struct ContentView:View {
#ObservedObject var item = MyItem()
var body:some View {
MySlider(value: $item.calories)
}
}
struct MySlider:View {
#Binding var value:Double
var body:some View {
VStack {
Text("\(value) ")
Slider(value: $value, in: 0...2000, step:5)
}
}
}
Everything works fine, but I can't get the text in MySlider to update as I mess with the Slider.

Answer 1

With property wrappers introduced in Swift 5.1, we can user #Published to simplify the state propagation. I refactored yours to user #Published. For the scenario mentioned this should work.
class MyItem: ObservableObject, Codable, Identifiable {
enum CodingKeys: String, CodingKey {
case id
case calories
}
var id = UUID()
#Published var calories: Double = 0
}
struct ContentView:View {
#ObservedObject var item = MyItem()
var body:some View {
MySlider(value: $item.calories)
}
}
struct MySlider:View {
#Binding var value:Double
var body:some View {
VStack {
Text("\(value) ")
Slider(value: $value, in: 0...2000, step:5)
}
}
}

Answer 2

#partha g—I was still getting a message from XCode saying that MyItem didn't conform to Codable. So after some digging, I added a couple inits and encode methods to get everything working the way I was expecting:
class MyItem: ObservableObject, Codable, Identifiable {
[...]
func encode(to encoder:Encoder) throws {
var container = encoder.container(keyedBy: CodingKeys.self)
try container.encode(calories, forKey: .calories)
}
required init(from decoder: Decoder) throws {
let container = try decoder.container(keyedBy: CodingKeys.self)
calories = try container.decode(Double.self, forKey: .calories)
}
init() { }
}
and voila.
Thanks for your help!