SwiftUI: When I unlock apps it takes me back to the list - core-data

Question

I have some problem with my application. When I lock it while I am in the content view and then unlock it, it takes me back to the list. I would like the view I was in before locking to still be visible after unlocking. I have tried to get this effect somehow but not successfully. Please, give me a hint.
What is more, if I click the heart and the item is marked as favorite, it also moves me back to the list. Here I would also like to remain in the view after selecting the heart. How can I eliminate this?

Answer 1

Here is a sample usage using Apple's sample code since you didn't provide any entity info
struct ContentView: View {
#Environment(\.managedObjectContext) private var viewContext
#FetchRequest(
sortDescriptors: [NSSortDescriptor(keyPath: \Item.timestamp, ascending: true)],
animation: .default)
private var items: FetchedResults<Item>
//SceneStorage to preserve the selected item by the user
#SceneStorage("ContentView.selection") var selection: String?
var body: some View {
NavigationView {
List {
ForEach(items) { item in
//Use the NavigationLink that uses selection
NavigationLink(tag: item.objectID.description, selection: $selection,
destination: {
//to edit/ observe the item pass it to an #ObservedObject
EditItemView2(item: item)
}, label: {
VStack{
Text(item.timestamp!, formatter: itemFormatter)
}
})
Button("delete", action: {
withAnimation(.easeOut(duration: 2)){
try? viewContext.delete(item)
}
})
}.onDelete(perform: deleteItems)
}
}
.toolbar {
#if os(iOS)
ToolbarItem(placement: .navigationBarTrailing) {
EditButton()
}
#endif
ToolbarItem {
Button(action: addItem) {
Label("Add Item", systemImage: "plus")
}
}
}
Text("Select an item")
}
private func addItem() {
withAnimation {
let newItem = Item(context: viewContext)
newItem.timestamp = Date()
do {
try viewContext.save()
} catch {
let nsError = error as NSError
fatalError("Unresolved error \(nsError), \(nsError.userInfo)")
}
}
}
private func deleteItems(offsets: IndexSet) {
withAnimation(.easeOut(duration: 2)) {
offsets.map { items[$0] }.forEach(viewContext.delete)
do {
try viewContext.save()
} catch {
let nsError = error as NSError
fatalError("Unresolved error \(nsError), \(nsError.userInfo)")
}
}
}
}
private let itemFormatter: DateFormatter = {
let formatter = DateFormatter()
formatter.dateStyle = .short
formatter.timeStyle = .medium
return formatter
}()
struct EditItemView2: View{
//This observes the item and allows changes to the object
#ObservedObject var item: Item
var body: some View{
DatePicker("timestamp", selection: $item.timestamp.bound)
}
}
This page talks all about it
https://developer.apple.com/documentation/uikit/view_controllers/restoring_your_app_s_state_with_swiftui

Answer 2

If your view is the first to create your UserSettings object, I recommend that you use #StateObject instead of #ObservedObject—and especially if that object is the only owner of the view and is not being observed by any other view.