SwiftUI disappear back button with navigationLink - ios

Question

I have 3 views. One of these have NavigationView second have NavigationLink and last just a child with toolbar.
So my problem when I added toolbar in last view backButton elegant disappear. How can I solve this?
Screen recording of my problem
import SwiftUI
struct ContentView: View {
var body: some View {
NavigationView {
VStack {
Text("Hello, world!")
.padding()
NavigationLink(destination: ListView()) {
Image(systemName: "trash")
.font(.largeTitle)
.foregroundColor(.red)
}
}.navigationBarHidden(true)
.navigationTitle("Image")
}
}
}
import SwiftUI
struct ListView: View {
#Environment(\.presentationMode) var presentationMode: Binding<PresentationMode>
var body: some View {
VStack {
List {
NavigationLink(destination: DetailView()) {
Text("Detail")
}
}
}.navigationBarTitle(Text("Data"), displayMode: .large)
.toolbar {
Button("Save") {
presentationMode.wrappedValue.dismiss()
}
}
}
}
import SwiftUI
struct DetailView: View {
#Environment(\.presentationMode) var presentationMode: Binding<PresentationMode>
var body: some View {
VStack {
Text("DetailView")
.padding()
}.navigationBarTitle(Text("Data"), displayMode: .large)
.toolbar {
Button("Save") {
presentationMode.wrappedValue.dismiss()
}
}
}
}

Answer 1

In the console, you'll notice this message:
2021-04-27 12:37:36.862733-0700 MyApp[12739:255441] [Assert] displayModeButtonItem is internally managed and not exposed for DoubleColumn style. Returning an empty, disconnected UIBarButtonItem to fulfill the non-null contract.
The default style for NavigationView is usually DefaultNavigationViewStyle, which is really just DoubleColumnNavigationViewStyle. Use StackNavigationViewStyle instead, and it works as expected.
Edit: You are right that StackNavigationViewStyle will break iPad split view. But thankfully, DoubleColumnNavigationViewStyle works fine in iPad and doesn't hide the back button. We can then just use a different NavigationStyle depending on the device, as shown in this answer.
struct ResponsiveNavigationStyle: ViewModifier {
#Environment(\.horizontalSizeClass) var horizontalSizeClass
#ViewBuilder
func body(content: Content) -> some View {
if horizontalSizeClass == .compact { /// iPhone
content.navigationViewStyle(StackNavigationViewStyle())
} else { /// iPad or larger iPhone in landscape
content.navigationViewStyle(DoubleColumnNavigationViewStyle())
}
}
}
struct ContentView: View {
var body: some View {
NavigationView {
VStack {
Text("Hello, world!")
.padding()
NavigationLink(destination: ListView()) {
Image(systemName: "trash")
.font(.largeTitle)
.foregroundColor(.red)
}
}
.navigationBarHidden(true)
.navigationTitle("Image")
}
.modifier(ResponsiveNavigationStyle()) /// here!
}
}
Result:
iPad
iPhone

Answer 2

I don't know why, but it's what worked for me:
.toolbar {
ToolbarItem(placement: .navigationBarTrailing) {
Button { } label: { } // button to the right
}
ToolbarItem(placement: .navigationBarLeading) {
Text("") // empty text in left to prevent back button to disappear
}
}
I already tried to replace the empty text with EmptyView() but the button keeps disappearing.
FYI: I have this problem only on my device with iOS 14, but in another device with iOS 15 the back button never disappears.