Custom back button for NavigationView's navigation bar in SwiftUI

Question

I want to add a custom navigation button that will look somewhat like this:

Now, I've written a custom BackButton view for this. When applying that view as leading navigation bar item, by doing:

.navigationBarItems(leading: BackButton())

...the navigation view looks like this:

I've played around with modifiers like:

.navigationBarItem(title: Text(""), titleDisplayMode: .automatic, hidesBackButton: true)

without any luck.

Question

How can I...

1. set a view used as custom back button in the navigation bar? OR:
2. programmatically pop the view back to its parent?
   When going for this approach, I could hide the navigation bar altogether using .navigationBarHidden(true)

Answer 1

TL;DR

Use this to transition to your view:

NavigationLink(destination: SampleDetails()) {}

Add this to the view itself:

@Environment(\.presentationMode) var presentationMode: Binding<PresentationMode>

Then, in a button action or something, dismiss the view:

presentationMode.value.dismiss()

---

Full code

From a parent, navigate using NavigationLink

 NavigationLink(destination: SampleDetails()) {}

In DetailsView hide navigationBarBackButton and set custom back button to leading navigationBatItem,

struct SampleDetails: View {
    @Environment(\.presentationMode) var presentationMode: Binding<PresentationMode>

    var btnBack : some View { Button(action: {
        self.presentationMode.value.dismiss()
        }) {
            HStack {
            Image("ic_back") // set image here
                .aspectRatio(contentMode: .fit)
                .foregroundColor(.white)
                Text("Go back")
            }
        }
    }

    var body: some View {
            List {
                Text("sample code")
        }
        .navigationBarBackButtonHidden(true)
        .navigationBarItems(leading: btnBack)
    }
}

Answer 2

Swift 1.0

It looks like you can now combine the navigationBarBackButtonHidden and .navigationBarItems to get the effect you're trying to achieve.

Code

struct Navigation_CustomBackButton_Detail: View {
    @Environment(\.presentationMode) var presentationMode

    var body: some View {
        ZStack {
            Color("Theme3BackgroundColor")
            VStack(spacing: 25) {
                Image(systemName: "globe").font(.largeTitle)
                Text("NavigationView").font(.largeTitle)
                Text("Custom Back Button").foregroundColor(.gray)
                HStack {
                    Image("NavBarBackButtonHidden")
                    Image(systemName: "plus")
                    Image("NavBarItems")
                }
                Text("Hide the system back button and then use the navigation bar items modifier to add your own.")
                    .frame(maxWidth: .infinity)
                    .padding()
                    .background(Color("Theme3ForegroundColor"))
                    .foregroundColor(Color("Theme3BackgroundColor"))

                Spacer()
            }
            .font(.title)
            .padding(.top, 50)
        }
        .navigationBarTitle(Text("Detail View"), displayMode: .inline)
        .edgesIgnoringSafeArea(.bottom)
        // Hide the system back button
        .navigationBarBackButtonHidden(true)
        // Add your custom back button here
        .navigationBarItems(leading:
            Button(action: {
                self.presentationMode.wrappedValue.dismiss()
            }) {
                HStack {
                    Image(systemName: "arrow.left.circle")
                    Text("Go Back")
                }
        })
    }
}

Example

Here is what it looks like (excerpt from the "SwiftUI Views" book):

Answer 3

Based on other answers here, this is a simplified answer for Option 2 working for me in XCode 11.0:

struct DetailView: View {
    @Environment(\.presentationMode) var presentationMode: Binding<PresentationMode>

    var body: some View {

        Button(action: {
           self.presentationMode.wrappedValue.dismiss()
        }) {
            Image(systemName: "gobackward").padding()
        }
        .navigationBarHidden(true)

    }
}

Note: To get the NavigationBar to be hidden, I also needed to set and then hide the NavigationBar in ContentView.

struct ContentView: View {
    var body: some View {
        NavigationView {
            VStack {
                NavigationLink(destination: DetailView()) {
                    Text("Link").padding()
                }
            } // Main VStack
            .navigationBarTitle("Home")
            .navigationBarHidden(true)

        } //NavigationView
    }
}

Answer 4

I found this: https://ryanashcraft.me/swiftui-programmatic-navigation/

It does work, and it may lay the foundation for a state machine to control what is showing, but it is not a simple as it was before.

import Combine
import SwiftUI

struct DetailView: View {
    var onDismiss: () -> Void

    var body: some View {
        Button(
            "Here are details. Tap to go back.",
            action: self.onDismiss
        )
    }
}

struct RootView: View {
    var link: NavigationDestinationLink<DetailView>
    var publisher: AnyPublisher<Void, Never>

    init() {
        let publisher = PassthroughSubject<Void, Never>()
        self.link = NavigationDestinationLink(
            DetailView(onDismiss: { publisher.send() }),
            isDetail: false
        )
        self.publisher = publisher.eraseToAnyPublisher()
    }

    var body: some View {
        VStack {
            Button("I am root. Tap for more details.", action: {
                self.link.presented?.value = true
            })
        }
            .onReceive(publisher, perform: { _ in
                self.link.presented?.value = false
            })
    }
}

struct ContentView: View {
    var body: some View {
        NavigationView {
            RootView()
        }
    }
}

If you want to hide the button then you can replace the DetailView with this:

struct LocalDetailView: View {
    var onDismiss: () -> Void

    var body: some View {
        Button(
            "Here are details. Tap to go back.",
            action: self.onDismiss
        )
            .navigationBarItems(leading: Text(""))
    }
}