I have no idea how to do it: on MacOS, in Document.init(configuration: ReadConfiguration) I decode file, and restore objects from data, which in some cases could take a long time. Document isn't fully inited, so I have no access to it. But would like to have a progress bar on screen (easier to wait for done, for now). I know size, progress value, but no idea how to make view from object during init. I know, this question may be very stupid. init(configuration: ReadConfiguration) throws { guard let data = configuration.file.regularFileContents else { throw CocoaError(.fileReadCorruptFile) } let decoder = JSONDecoder() let flat = try decoder.decode(FlatDoc.self, from: data) print ("reverting \(flat.objects.count) objects...") ///This takes time, a lot of time, need progress bar ///Total is `flat.objects.count`, current is `objects.count` /// `Show me a way to the (next) progress bar!` revertObjects(from: flat.objects) print ("...done") } update: I defined var flatObjects in Document, and I can convert in .onAppear. struct TestApp: App { @State var isLoading = false ... ContentView(document: file.$document) .onAppear { isLoading = true Task {file.document.revertObjects()} isLoading = false } if isLoading { ProgressView() } ... } But progress bar never shows, only rainbow ball