Async ObservableObject

AsyncObservableObject.swift

import SwiftUI

@MainActor
class PhotoStore: ObservableObject {
    @Published private(set) var isSaving: Bool = false

    // Made nonisolated because Playgrounds does not run on
    // @MainActor. There's probably a cleaner way of doing this
    nonisolated init() {}

    func savePhoto(_ photo: Any) async -> Bool {
        isSaving = true
        await withUnsafeContinuation { c in
            DispatchQueue.global().asyncAfter(deadline: .now() + 1) {
                c.resume()
            }
        }
        isSaving = false
        return true
    }
}

struct AsyncObservableRootView: View {
    @StateObject var store: PhotoStore

    var body: some View {
        SavePhotoButton(photo: (), store: store)
    }
}

struct SavePhotoButton: View {
    var photo: Any
    @ObservedObject private(set) var store: PhotoStore

    var body: some View {
        Button {
            async {
                await store.savePhoto(())
            }
        } label: {
            Text("Save")
                .opacity(store.isSaving ? 0 : 1)
                .overlay {
                    if store.isSaving {
                        ProgressView()
                    }
                }
        }
        .disabled(store.isSaving)
        .buttonStyle(.bordered)
    }
}