iOS SwiftUI: pop or dismiss view programmatically - ios

Question

I couldn't find any reference about any ways to make a pop or a dismiss programmatically of my presented view with SwiftUI.
Seems to me that the only way is to use the already integrated slide dow action for the modal(and what/how if I want to disable this feature?), and the back button for the navigation stack.
Does anyone know a solution?
Do you know if this is a bug or it will stays like this?

Answer 1

This example uses the new environment var documented in the Beta 5 Release Notes, which was using a value property. It was changed in a later beta to use a wrappedValue property. This example is now current for the GM version. This exact same concept works to dismiss Modal views presented with the .sheet modifier.
import SwiftUI
struct DetailView: View {
#Environment(\.presentationMode) var presentationMode: Binding<PresentationMode>
var body: some View {
Button(
"Here is Detail View. Tap to go back.",
action: { self.presentationMode.wrappedValue.dismiss() }
)
}
}
struct RootView: View {
var body: some View {
VStack {
NavigationLink(destination: DetailView())
{ Text("I am Root. Tap for Detail View.") }
}
}
}
struct ContentView: View {
var body: some View {
NavigationView {
RootView()
}
}
}

Answer 2

SwiftUI Xcode Beta 5
First, declare the #Environment which has a dismiss method which you can use anywhere to dismiss the view.
import SwiftUI
struct GameView: View {
#Environment(\.presentationMode) var presentation
var body: some View {
Button("Done") {
self.presentation.wrappedValue.dismiss()
}
}
}

Answer 3

iOS 15+
Starting from iOS 15 we can use a new #Environment(\.dismiss):
struct SheetView: View {
#Environment(\.dismiss) var dismiss
var body: some View {
NavigationView {
Text("Sheet")
.toolbar {
Button("Done") {
dismiss()
}
}
}
}
}
(There's no more need to use presentationMode.wrappedValue.dismiss().)
Useful links:
DismissAction

Answer 4

There is now a way to programmatically pop in a NavigationView, if you would like. This is in beta 5. Notice that you don't need the back button. You could programmatically trigger the showSelf property in the DetailView any way you like. And you don't have to display the "Push" text in the master. That could be an EmptyView(), thereby creating an invisible segue.
import SwiftUI
struct ContentView: View {
var body: some View {
NavigationView {
MasterView()
}
}
}
struct MasterView: View {
#State private var showDetail = false
var body: some View {
VStack {
NavigationLink(destination: DetailView(showSelf: $showDetail), isActive: $showDetail) {
Text("Push")
}
}
}
}
struct DetailView: View {
#Binding var showSelf: Bool
var body: some View {
Button(action: {
self.showSelf = false
}) {
Text("Pop")
}
}
}
#if DEBUG
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
#endif

Answer 5

I recently created an open source project called swiftui-navigation-stack (https://github.com/biobeats/swiftui-navigation-stack) that contains the NavigationStackView, an alternative navigation stack for SwiftUI. It offers several features described in the readme of the repo. For example, you can easily push and pop views programmatically. I'll show you how to do that with a simple example:
First of all embed your hierarchy in a NavigationStackVew:
struct RootView: View {
var body: some View {
NavigationStackView {
View1()
}
}
}
NavigationStackView gives your hierarchy access to a useful environment object called NavigationStack. You can use it to, for instance, pop views programmatically as asked in the question above:
struct View1: View {
var body: some View {
ZStack {
Color.yellow.edgesIgnoringSafeArea(.all)
VStack {
Text("VIEW 1")
Spacer()
PushView(destination: View2()) {
Text("PUSH TO VIEW 2")
}
}
}
}
}
struct View2: View {
#EnvironmentObject var navStack: NavigationStack
var body: some View {
ZStack {
Color.green.edgesIgnoringSafeArea(.all)
VStack {
Text("VIEW 2")
Spacer()
Button(action: {
self.navStack.pop()
}, label: {
Text("PROGRAMMATICALLY POP TO VIEW 1")
})
}
}
}
}
In this example I use the PushView to trigger the push navigation with a tap. Then, in the View2 I use the environment object to programmatically come back.
Here is the complete example:
import SwiftUI
import NavigationStack
struct RootView: View {
var body: some View {
NavigationStackView {
View1()
}
}
}
struct View1: View {
var body: some View {
ZStack {
Color.yellow.edgesIgnoringSafeArea(.all)
VStack {
Text("VIEW 1")
Spacer()
PushView(destination: View2()) {
Text("PUSH TO VIEW 2")
}
}
}
}
}
struct View2: View {
#EnvironmentObject var navStack: NavigationStack
var body: some View {
ZStack {
Color.green.edgesIgnoringSafeArea(.all)
VStack {
Text("VIEW 2")
Spacer()
Button(action: {
self.navStack.pop()
}, label: {
Text("PROGRAMMATICALLY POP TO VIEW 1")
})
}
}
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
RootView()
}
}
the result is:

Answer 6

Alternatively, if you don't want to do it programatically from a button, you can emit from the view model whenever you need to pop.
Subscribe to a #Published that changes the value whenever the saving is done.
struct ContentView: View {
#ObservedObject var viewModel: ContentViewModel
#Environment(\.presentationMode) var presentationMode
init(viewModel: ContentViewModel) {
self.viewModel = viewModel
}
var body: some View {
Form {
TextField("Name", text: $viewModel.name)
.textContentType(.name)
}
.onAppear {
self.viewModel.cancellable = self.viewModel
.$saved
.sink(receiveValue: { saved in
guard saved else { return }
self.presentationMode.wrappedValue.dismiss()
}
)
}
}
}
class ContentViewModel: ObservableObject {
#Published var saved = false // This can store any value.
#Published var name = ""
var cancellable: AnyCancellable? // You can use a cancellable set if you have multiple observers.
func onSave() {
// Do the save.
// Emit the new value.
saved = true
}
}

Answer 7

Please check Following Code it's so simple.
FirstView
struct StartUpVC: View {
#State var selection: Int? = nil
var body: some View {
NavigationView{
NavigationLink(destination: LoginView().hiddenNavigationBarStyle(), tag: 1, selection: $selection) {
Button(action: {
print("Signup tapped")
self.selection = 1
}) {
HStack {
Spacer()
Text("Sign up")
Spacer()
}
}
}
}
}
SecondView
struct LoginView: View {
#Environment(\.presentationMode) var presentationMode
var body: some View {
NavigationView{
Button(action: {
print("Login tapped")
self.presentationMode.wrappedValue.dismiss()
}) {
HStack {
Image("Back")
.resizable()
.frame(width: 20, height: 20)
.padding(.leading, 20)
}
}
}
}
}

Answer 8

You can try using a custom view and a Transition.
Here's a custom modal.
struct ModalView<Content>: View where Content: View {
#Binding var isShowing: Bool
var content: () -> Content
var body: some View {
GeometryReader { geometry in
ZStack(alignment: .center) {
if (!self.isShowing) {
self.content()
}
if (self.isShowing) {
self.content()
.disabled(true)
.blur(radius: 3)
VStack {
Text("Modal")
}
.frame(width: geometry.size.width / 2,
height: geometry.size.height / 5)
.background(Color.secondary.colorInvert())
.foregroundColor(Color.primary)
.cornerRadius(20)
.transition(.moveAndFade) // associated transition to the modal view
}
}
}
}
}
I reused the Transition.moveAndFade from the Animation Views and Transition tutorial.
It is defined like this:
extension AnyTransition {
static var moveAndFade: AnyTransition {
let insertion = AnyTransition.move(edge: .trailing)
.combined(with: .opacity)
let removal = AnyTransition.scale()
.combined(with: .opacity)
return .asymmetric(insertion: insertion, removal: removal)
}
}
You can test it - in the simulator, not in the preview - like this:
struct ContentView: View {
#State var isShowingModal: Bool = false
func toggleModal() {
DispatchQueue.main.asyncAfter(deadline: .now() + 3) {
withAnimation {
self.isShowingModal = true
}
DispatchQueue.main.asyncAfter(deadline: .now() + 3) {
withAnimation {
self.isShowingModal = false
}
}
}
}
var body: some View {
ModalView(isShowing: $isShowingModal) {
NavigationView {
List(["1", "2", "3", "4", "5"].identified(by: \.self)) { row in
Text(row)
}.navigationBarTitle(Text("A List"), displayMode: .large)
}.onAppear { self.toggleModal() }
}
}
}
Thanks to that transition, you will see the modal sliding in from the trailing edge, and the it will zoom and fade out when it is dismissed.

Answer 9

The core concept of SwiftUI is to watch over the data flow.
You have to use a #State variable and mutate the value of this variable to control popping and dismissal.
struct MyView: View {
#State
var showsUp = false
var body: some View {
Button(action: { self.showsUp.toggle() }) {
Text("Pop")
}
.presentation(
showsUp ? Modal(
Button(action: { self.showsUp.toggle() }) {
Text("Dismiss")
}
) : nil
)
}
}

Answer 10

I experienced a compiler issue trying to call value on the presentationMode binding. Changing the property to wrappedValue fixed the issue for me. I'm assuming value -> wrappedValue is a language update. I think this note would be more appropriate as a comment on Chuck H's answer but don't have enough rep points to comment, I also suggested this change as and edit but my edit was rejected as being more appropriate as a comment or answer.

Answer 11

This will also dismiss the view
let scenes = UIApplication.shared.connectedScenes
let windowScene = scenes.first as? UIWindowScene
let window = windowScene?.windows.first
window?.rootViewController?.dismiss(animated: true, completion: {
print("dismissed")
})