iOS SwiftUI: Data Flow Flow in Subviews #ObservedObject - ios

Question

I'm having a problem of updates in my application.
I can't understand very well what is going on with the data flow between the subviews.
This is my current structure
ViewModel: ObsebsrvableObject
MainView with ObservedObject (viewModel)
ChildView with a list from MainView observed object (just the list is passed as a normal array - not bindable)
NephewView with the list passed to the childView, still as a normal array
What is happening:
Every time I modify the list, the MainView updates triggering a new rebuild of ChildView, but the NephewView does not update
What I would like to have:
I would like to update the Main, the Child and the NephewView views every time the observedObject get an update
Problem:
I can't understand why if the Child View rebuild, the nephew doesn't.
Example Code
class ViewModel: ObservableObject {
let userData = UserData.shared
var canceller: AnyCancellable?
#Published var items: [Items]
init() {
items = []
canceller = userData.objectWillChange
.throttle(for: 5, scheduler: RunLoop.main, latest: true)
.sink(receiveCompletion: { data in
DispatchQueue.main.async { [weak self] in
guard let self = self else { return }
self.items = data.items
}
},
receiveValue: { _ in
DispatchQueue.main.async { [weak self] in
guard let self = self else { return }
self.items = data.items
}
})
}
}
struct MainView: View {
#ObservedObject var model = ViewModel()
var body: some View {
ChildView(items: model.items)
}
}
struct ChildView: View {
let items: [Items]
var body: some View {
NephewView(items: items)
}
}
struct NephewView: View {
let items: [Items]
var body: some View {
List...
}
}
The sink works properly, it's just the UI part that does not get updates.
Maybe the way I'm updating the publisher is wrong?

Answer 1

Your MainView
ChildView(items: $model.items)
Your ChildView
struct ChildView: View {
#Binding let items: [Items]
var body: some View {
List {
ForEach(self.items) { item in
NephewView(items: item)
}
}
}
}
Your NephewView
struct NephewView: View {
#Binding let items: item
var body: some View {
// Your view logic goes here with single item
}
}