Let's say I'm building app for viewing and editing posts. Here's my model for Post and app itself:

struct Post: Hashable {
    var id: Int
    var title: String
}

class Store: ObservableObject {
    // 
    // In real-life this should be fetched via API on app/view start
    //
    @Published var items: [Post] = [
        Post(id: 1, title: "Foo"),
        Post(id: 2, title: "Bar"),
        Post(id: 3, title: "baz"),
    ]
}

@main
struct PlaygoundApp: App {
    @StateObject var store = Store()

    var body: some Scene {
        WindowGroup {
            ContentView()
                .environmentObject(store)
        }
    }
}

And here's the list with all posts. I can navigate to each post's own view and edit post data (usually via API):

struct ContentView: View {
    @EnvironmentObject var store: Store

    var body: some View {
        NavigationView {
            List {
                ForEach(store.items, id: \.self) { post in
                    NavigationLink(destination: PostView(post: post).navigationTitle(post.title)) {
                        Text(post.title)
                    }
                }
            }
        }
    }
}

struct PostView: View {
    var post: Post

    var body: some View {
        Text(post.title)
        Button(action: {
            //
            // Make API call and edit Post title
            /// THIS WILL NOT COMPILE
            // post.title = "New title"
            // 
        }, label: {
            Text("Edit title")
        })
    }
}

So if I try to edit post (directly or after API call, it doen't matter), I:

1. can't assign new value to existing var post: Post struct from post itself
2. cant trigger view to be re-rendered

What is the correnct approach to reflect data changes in existing Observable storage? I thought of two ways to fix it:

1. make method like store.fetch_posts() and call it after pressing button, but this will trigger to re-render all post view and reset scrolling position, and likely it will not work at all as expected
2. in Ios15 there's abillity to iterate over bindings (https://www.swiftbysundell.com/articles/bindable-swiftui-list-elements/). I thought this might be a solution, but there should be existing way to handle such a generic usecase

Thank you

Solved:

1. Make post ObservedObject;
2. Make Post class instead of struct.

Thank you! Turned back to Struct because with Class I've got very strange bugs with non-updating views due to its mutating nature.