SwiftUI: Involuntary ping pong when editing and saving detailed view / NavigationLink

1. an involuntary navigation back to the list view and then again back to the detailed view or

2. an involuntary navigation to another copy of the same detailed view and then back to the list view.

Code Block swiftui
struct ContentView: View {
		var body: some View {
				TabView {
						NavigationView {
								TasksListView()
						}
						.tabItem {
								Image(systemName: "tray.full")
										.font(.title)
								Text("Master")
						}
						NavigationView {
								EmptyView()
						}
						.tabItem {
								Image(systemName: "magnifyingglass")
										.font(.title)
								Text("Search")
						}
				}	
		}
}
struct TasksListView: View {
		
		// NSManagedObjectContext
		@Environment(\.managedObjectContext) var viewContext
		// Results of fetch request for tasks:
		@FetchRequest(entity: Task.entity(),sortDescriptors: [NSSortDescriptor(key: "pinned", ascending: false),
																													NSSortDescriptor(key: "created", ascending: true),
																													NSSortDescriptor(key: "name", ascending: true)])
		var tasks: FetchedResults<Task>
		
		// when we create a new task and navigate to it programitically
		@State var selectionId : String?
		@State var newTask : Task?
		var body: some View {
				
				List() {
						ForEach(tasks, id: \.self) { task in
								NavigationLink(destination: DetailsView(task: task), tag: task.id!.uuidString, selection: self.$selectionId) {
										HStack() {
												VStack(alignment: .leading) {
														Text("\(task.name ?? "unknown")")
																.font(Font.headline.weight(.light))
																.padding(.bottom,5)
														Text("Created:\t\(task.created ?? Date(), formatter: Self.dateFormatter)")
																.font(Font.subheadline.weight(.light))
																.padding(.bottom,5)
														if task.due != nil {
																Text("Due:\t\t\(task.due!, formatter: Self.dateFormatter)")
																		.font(Font.subheadline.weight(.light))
																		.padding(.bottom,5)
														}
												}
										}
								}
								
						}
				}
				.navigationBarTitle(Text("Tasks"),displayMode: .inline)
				.navigationBarItems(trailing: rightButton)
		}
		
		
		var rightButton: some View {
				Image(systemName: "plus.circle")
						.foregroundColor(Color(UIColor.systemBlue))
						.font(.title)
						.contentShape(Rectangle())
						.onTapGesture {
								// create a new task and navigate to it's detailed view to add values
								Task.create(in: self.viewContext) { (task, success, error) in
										if success {
												self.newTask = task
												self.selectionId = task!.id!.uuidString
										}
								}
								
				}
		}
}
-- continued

Code Block swiftui
struct DetailsView: View {
    @Environment(\.managedObjectContext) var viewContext
    @ObservedObject var task : Task
    @State var isPinned : Bool = false
    var body: some View {
        List() {
            Section() {
                Toggle(isOn: self.$isPinned) {
                    Text("Pinned")
                }
            }
            Section() {
                TextField("Name", text: self.$name)
                    .font(Font.headline.weight(.light)
            }
		....
        }
        .navigationBarTitle(Text("Task Details"),displayMode: .inline)
        .navigationBarItems(trailing: rightButton)
        .listStyle(GroupedListStyle())
        .onAppear() {
            if self.task.pinned {
                self.isPinned = true
            }
        }
    }
    var rightButton: some View {
        Button("Save") {
            self.task.pinned = self.isPinned
			Task.save(in: self.viewContext) { (success, error) in
                DispatchQueue.main.async {
					....
                }
            }
        }
    }
}

Code Block swift
extension Task {
    static func save(in managedObjectContext: NSManagedObjectContext, completion: @escaping (Bool, NSError?) -> Void ) {
        managedObjectContext.performAndWait() {
            do {
                try managedObjectContext.save()
                completion(true, nil)
            } catch {
                let nserror = error as NSError
                completion(false, nserror)
            }
        }
     }
}

• added BOOL property 'pinned' to the core data Entity

• added Toggle view to the DetailView

• added save button to the DetailedView

• changed the NSSortDescriptor to use pinned property

• an involuntary navigation back to the list view and then again back to the detailed view or

• an involuntary navigation to another copy of the same detailed view and then back to the list view.