Hiding the SideBar when presenting a NavigationLink

Can you show your latest code?

Here's some base code (slightly modified boiler plate). At the moment, selecting the item just opens the detail view in the right column. I want the sidebar (left column) to slide away as soon as I select an item.

 
import CoreData
 
 
 
struct DetailView: View {
 
    @Environment(\.managedObjectContext) private var viewContext
 
    @ObservedObject var item: Item
 
    
 
    func save() {
 
        do {
 
            try viewContext.save()
 
            
 
        } catch {
 
            var nserror  = error as NSError
 
            fatalError("Unresolved error: \(nserror)")
 
        }
 
    }
 
    
 
    var body: some View {
 
    
 
        Text("Item timestamp: \(item.timestamp!)")
 
        Button(action: {
 
            
 
            item.setElement(data: item.values!, row: 0, col: 2, val: item.getElement(data: item.values!, row: 0, col: 2) + 1)
 
            save()
 
        }) {
 
            Text("Add one")
 
        }
 
    }
 
}
 
 
 
struct ContentView: View {
 
    @Environment(\.managedObjectContext) private var viewContext
 
 
 
    @FetchRequest(
 
        sortDescriptors: [NSSortDescriptor(keyPath: \Item.timestamp, ascending: true)],
 
        animation: .default)
 
    private var items: FetchedResults<Item>
 
 
 
    var body: some View {
 
        NavigationView {
 
            List {
 
                ForEach(items) { item in
 
                    NavigationLink(destination: DetailView(item: item)) {
 
                        Text("Item at \(item.timestamp!, formatter: itemFormatter)")
 
                    }
 
                }
 
                .onDelete(perform: deleteItems)
 
            }
 
            .toolbar {
 
                #if os(iOS)
 
                ToolbarItem(placement: .bottomBar) {
 
                    EditButton()
 
                }
 
                #endif
 
                ToolbarItem(placement: .primaryAction) {
 
                    Button(action: addItem) {
 
                        Label("Add Item", systemImage: "plus")
 
                    }
 
                }
 
            }
 
        }
 
    }
 
    
 
    /*
 
     let value: [Int16] = [1, Int16.max, Int16.min]
 
     let data = Data(fromArray: value)
 
     print(data as NSData) // <0100ff7f 0080>
 
 
 
     let roundtrip = data.toArray(type: Int16.self)
 
     print(roundtrip) // [1, 32767, -32768]
 
     */
 
    private func addItem() {
 
        withAnimation {
 
            let newItem = Item(context: viewContext)
 
            newItem.timestamp = Date()
 
            do {
 
                try viewContext.save()
 
            } catch {
 
                // Replace this implementation with code to handle the error appropriately.
 
                // fatalError() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
 
                let nsError = error as NSError
 
                fatalError("Unresolved error \(nsError), \(nsError.userInfo)")
 
            }
 
        }
 
    }
 
 
 
    private func deleteItems(offsets: IndexSet) {
 
        withAnimation {
 
            offsets.map { items[$0] }.forEach(viewContext.delete)
 
 
 
            do {
 
                try viewContext.save()
 
            } catch {
 
                // Replace this implementation with code to handle the error appropriately.
 
                // fatalError() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
 
                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 ContentView_Previews: PreviewProvider {
 
    static var previews: some View {
 
        ContentView().environment(\.managedObjectContext, PersistenceController.preview.container.viewContext)
 
    }
 
}

Sorry for the late response. With lacking Item or some other parts, I needed to find some chance I could spend plenty of time.

Only iPad.

Have you tried adding navigationViewStyle?

        NavigationView {
            //...
        }
        .navigationViewStyle(StackNavigationViewStyle())