I'm working with SwiftUI and I have a starting page. When a user presses a button on this page, a modal sheet pops up.
In side the modal sheet, I have some code like this:
NavigationLink(destination: NextView(), tag: 2, selection: $tag) {
EmptyView()
}
and my modal sheet view is wrapped inside of a Navigation View.
When the value of tag becomes 2, the view does indeed go to NextView(), but it's also presented as a modal sheet that the user can swipe down from, and I don't want this.
I'd like to transition from a modal sheet to a regular view.
Is this possible? I've tried hiding the navigation bar, etc. but it doesn't seem to make a difference.
Any help with this matter would be appreciated.
You can do this by creating an environmentObject and bind the navigationLink destination value to the environmentObject's value then change the value of the environmentObject in the modal view.
Here is a code explaining what I mean
import SwiftUI
class NavigationManager: ObservableObject{
#Published private(set) var dest: AnyView? = nil
#Published var isActive: Bool = false
func move(to: AnyView) {
self.dest = to
self.isActive = true
}
}
struct StackOverflow6: View {
#State var showModal: Bool = false
#EnvironmentObject var navigationManager: NavigationManager
var body: some View {
NavigationView {
ZStack {
NavigationLink(destination: self.navigationManager.dest, isActive: self.$navigationManager.isActive) {
EmptyView()
}
Button(action: {
self.showModal.toggle()
}) {
Text("Show Modal")
}
}
}
.sheet(isPresented: self.$showModal) {
secondView(isPresented: self.$showModal).environmentObject(self.navigationManager)
}
}
}
struct StackOverflow6_Previews: PreviewProvider {
static var previews: some View {
StackOverflow6().environmentObject(NavigationManager())
}
}
struct secondView: View {
#EnvironmentObject var navigationManager: NavigationManager
#Binding var isPresented: Bool
#State var dest: AnyView? = nil
var body: some View {
VStack {
Text("Modal view")
Button(action: {
self.isPresented = false
self.dest = AnyView(thirdView())
}) {
Text("Press me to navigate")
}
}
.onDisappear {
// This code can run any where but I placed it in `.onDisappear` so you can see the animation
if let dest = self.dest {
self.navigationManager.move(to: dest)
}
}
}
}
struct thirdView: View {
var body: some View {
Text("3rd")
.navigationBarTitle(Text("3rd View"))
}
}
Hope this helps, if you have any questions regarding this code, please let me know.
Related
Consider the following example with a list and a button wrapped in a HStack that opens up a sheet:
struct ContentView: View {
#State var text: String = ""
#State var showSheet = false
var body: some View {
NavigationView {
List {
HStack {
button
}
Text("Hello World")
}
.searchable(text: $text)
}
}
var button: some View {
Button("Press", action: { showSheet = true })
.sheet(isPresented: $showSheet) {
modalView
}
}
var modalView: some View {
NavigationView {
List {
Text("Test")
}
}
}
}
On press of the button, a modal is presented to the user. However, the searchable modifier gets passed to the modal, see this video.
Now if the HStack is removed, everything works fine:
List {
button
Text("Hello World")
}
In addition, everything works also fine if the modal is not a NavigationView:
var modalView: some View {
List {
Text("Test")
}
}
Does somebody know what the problem here might be or is it once again one of those weird SwiftUI bugs?
putting the sheet, outside of the button and the List, works for me. I think .sheet is not meant to be inside a List, especially where searchable is operating.
struct ContentView: View {
#State var text: String = ""
#State var showSheet = false
var body: some View {
NavigationView {
List {
HStack {
button
}
Text("Hello World")
}
.searchable(text: $text)
}
.sheet(isPresented: $showSheet) {
modalView
}
}
var button: some View {
Button("Press", action: { showSheet = true })
}
var modalView: some View {
NavigationView {
List {
Text("Test")
}
}
}
}
Another workaround is to use navigationBarHidden = true, but then you must live without the navigation bar in the sheet view.
var modalView: some View {
NavigationView {
List {
Text("Test")
}
.navigationBarHidden(true)
}
}
Btw, on iPadOS it helps to use .searchable(text: $text, placement: .sidebar)
Set property wrapper to pop view "#Environment(.presentationMode) var presentationMode" but it is reloading view again and again. Why it is happening? any solution?
What i have observed except #Environment(.presentationMode) we should use bool value binding with controller, Please check code:
struct newView: View {
#State private var isActiveView: Bool = false
var body: some View {
VStack(alignment: .center) {
NavigationLink(destination: PushedView(isActiveView: $isActiveView), isActive: $isActiveView) {
Text("Create Account")
}
}
}
}
And on pushed screen check the code:
`struct PushedView: View {
#Binding var isActiveView: Bool
var body: some View {
NavigationView {
VStack {
Text(“Back”).onTapGesture {
isActiveView = false // to pop into previous view
}
}
}
}
}
`
In SwiftUI I couldn't find a way to detect when the user taps on the default back button of the navigation view when I am inside DetailView1 in this code:
struct RootView: View {
#State private var showDetails: Bool = false
var body: some View {
NavigationView {
VStack {
NavigationLink(destination: DetailView1(), isActive: $showDetails) {
Text("show DetailView1")
}
}
.navigationBarTitle("RootView")
}
}
}
struct DetailView1: View {
#State private var showDetails: Bool = false
var body: some View {
NavigationLink(destination: DetailView2(), isActive: $showDetails) {
Text("show DetailView2")
}
.navigationBarTitle("DetailView1")
}
}
struct DetailView2: View {
var body: some View {
Text("")
.navigationBarTitle("DetailView2")
}
}
Using .onDisappear doesn't solve the problem as its closure is called when the view is popped off or a new view is pushed.
The quick solution is to create a custom back button because right now the framework have not this possibility.
struct DetailView : View {
#Environment(\.presentationMode) var mode: Binding<PresentationMode>
var body : some View {
Text("Detail View")
.navigationBarBackButtonHidden(true)
.navigationBarItems(leading: Button(action : {
self.mode.wrappedValue.dismiss()
}){
Image(systemName: "arrow.left")
})
}
}
As soon as you press the back button, the view sets isPresented to false, so you can use an observer on that value to trigger code when the back button is pressed. Assume this view is presented inside a navigation controller:
struct MyView: View {
#Environment(\.isPresented) var isPresented
var body: some View {
Rectangle().onChange(of: isPresented) { newValue in
if !newValue {
print("detail view is dismissed")
}
}
}
}
An even nicer (SwiftUI-ier?) way of observing the published showDetails property:
struct RootView: View {
class ViewModel: ObservableObject {
#Published var showDetails = false
}
#ObservedObject var viewModel = ViewModel()
var body: some View {
NavigationView {
VStack {
NavigationLink(destination: DetailView1(), isActive: $viewModel.showDetails) {
Text("show DetailView1")
}
}
.navigationBarTitle("RootView")
.onReceive(self.viewModel.$showDetails) { isShowing in
debugPrint(isShowing)
// Maybe do something here?
}
}
}
}
Following up on my comment, I would react to changes in the state of showDetails. Unfortunately didSet doesn't appear to trigger with #State variables. Instead, we can use an observable view model to hold the state, which does allow us to do intercept changes with didSet.
struct RootView: View {
class ViewModel: ObservableObject {
#Published var showDetails = false {
didSet {
debugPrint(showDetails)
// Maybe do something here?
}
}
}
#ObservedObject var viewModel = ViewModel()
var body: some View {
NavigationView {
VStack {
NavigationLink(destination: DetailView1(), isActive: $viewModel.showDetails) {
Text("show DetailView1")
}
}
.navigationBarTitle("RootView")
}
}
}
I have two screens, a master and a detail, detail has an ObservedObject that has it's state. I also want to hide the navigation bar on master and show it on detail. To do that, I have the navigation bar hidden status as a #State property on master view and send it back to the detail view as a Binding variable.
The problem I'm having is that whenever I update that variable inside the detail screen, the ObservedObject stops working.
Here's a sample code that reproduces the issue:
struct ContentView: View {
#State var navigationBarHidden = true
var body: some View {
NavigationView {
VStack {
NavigationLink(destination: DetailView(navigationBarHidden: $navigationBarHidden)) {
Text("Go Forward")
}
}
.navigationBarTitle("", displayMode: .inline)
.navigationBarHidden(navigationBarHidden)
.onAppear { self.navigationBarHidden = true }
}
}
}
class DetailViewModel: ObservableObject {
#Published var text = "Didn't work"
}
struct DetailView: View {
#Binding var navigationBarHidden: Bool
#ObservedObject var viewModel = DetailViewModel()
var body: some View {
VStack {
Text(viewModel.text)
}.onAppear {
self.navigationBarHidden = false
self.viewModel.text = "Worked"
}
}
}
If I leave it as is, the text will not update to "Worked". If I remove the line self.navigationBarHidden = false, the ObservedObject will work properly and the text will update.
How can I achieve the expected behavior, update the navigation bar while keeping my observed object working?
The reason is, that
NavigationLink(destination: DetailView(navigationBarHidden: $navigationBarHidden)) {
Text("Go Forward")
}
create new DetailView and so on new DetailViewModel when activating
try
import SwiftUI
struct ContentView: View {
#State var navigationBarHidden = true
#ObservedObject var viewModel = DetailViewModel()
var body: some View {
NavigationView {
VStack {
NavigationLink(destination: DetailView(navigationBarHidden: $navigationBarHidden).environmentObject(viewModel)) {
Text("Go Forward")
}
}
.navigationBarTitle("", displayMode: .inline)
.navigationBarHidden(navigationBarHidden)
.onAppear { self.navigationBarHidden = true }
}
}
}
class DetailViewModel: ObservableObject {
#Published var text = "Didn't work"
}
struct DetailView: View {
#Binding var navigationBarHidden: Bool
#EnvironmentObject var viewModel: DetailViewModel
var body: some View {
VStack {
Text(viewModel.text)
}.onAppear {
self.navigationBarHidden = false
self.viewModel.text = "Worked"
}
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
Now you share the model with DetailView and it works as expected (written)
If I remove the line self.navigationBarHidden = false, the
ObservedObject will work properly and the text will update.
If you remove this line, the DetailView in not recreated (there is nothing changed in View) State is not part of View state, it is reference type, so SwiftUI don't see any changes until some values which are wrapped by them change.
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?
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()
}
}
}
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()
}
}
}
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
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
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:
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
}
}
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)
}
}
}
}
}
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.
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
)
}
}
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.
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")
})