SwiftUI NavigationLink for iOS 14.5 not working - ios

I had the following code in Xcode 12.4 that worked perfectly
ScrollView(.horizontal, showsIndicators: false) {
LazyHGrid(rows: rows, spacing: 0) {
HStack {
if (type == "Quiz") {
NavigationLink(destination: Quiz(id: quiz.id)) {
VStack(alignment: .leading) {
Text("Quiz")
.font(.headline)
.foregroundColor(.white)
.padding(.top, 8)
.padding(.leading)
}
.background(Color.green)
.cornerRadius(12)
.shadow(color: .green, radius: 3, x: 0.0, y: 0.0)
}
} else {
NavigationLink(destination: Survey(id: survey.id)) {
VStack(alignment: .leading) {
Text("Survey")
.font(.headline)
.foregroundColor(.white)
.padding(.top, 8)
.padding(.leading)
}
.background(Color.green)
.cornerRadius(12)
.shadow(color: .green, radius: 3, x: 0.0, y: 0.0)
}
} // End If
if (type == "Quiz") {
NavigationLink(destination: QuizResults(id: quiz.id)) {
VStack(alignment: .leading) {
Text("Quiz Results")
.font(.headline)
.foregroundColor(.white)
.padding(.top, 8)
.padding(.leading)
}
.background(Color.blue)
.cornerRadius(12)
.shadow(color: .blue, radius: 3, x: 0.0, y: 0.0)
}
} else {
NavigationLink(destination: SurveyResults(id: survey.id)) {
VStack(alignment: .leading) {
Text("Survey Results")
.font(.headline)
.foregroundColor(.white)
.padding(.top, 8)
.padding(.leading)
}
.background(Color.blue)
.cornerRadius(12)
.shadow(color: .blue, radius: 3, x: 0.0, y: 0.0)
}
}
}
.padding([.leading, .trailing], 25)
}
.frame(height: 100)
I just updated Xcode to 12.5 and the above does not work any more.
It was working fine in 12.4!?
Now when I click the 'Quiz' element, it starts the transition to the Quiz View which is displays it but immediately closes the view and I'm back in the Detail View!?
Can someone see what I am doing wrong, and why now based on the update to 12.5 this stopped working?
UPDATE
I refined the code to the minimal possible reproducible form. What seems to be happening is that I have two or more NavigationLinks sets.
the first is the set to navigate the user to either the Quiz or Survey which the if statement addresses the user to the correct view to fill in.
Where the issue is in 12.5 is that the second set where the user can click to go see the overall results of the Quiz or Survey does not work when it's directly after the first navigation.
Like I said before hand it worked perfectly in 12.4 but seems like 12.5 does not agree with it. Can someone offer a better way for the user to click an element to either go fill in a quiz or survey or go see the results of a quiz or survey?

I got exactly the same problem, everything works fine with Xcode 12.4.
https://developer.apple.com/forums/thread/677333
I try to following this thread, it might work but on some case, I still have this bug.
NavigationLink(destination: EmptyView()) {
EmptyView()
}
Apparently, you can put this 3 lines of code close to your NavigationLink...
If someone got a better answer I will really appreciate it !

What a horrible bug! From my testing and some googling it happens when there are exactly 2 navigation links in a view. The code in the question has 4 but because of the if else statements there are effectively only 2 at a time.
I often don't know how many nav links I will have as it depends on what data the user has added/how many search hits there are etc. To be safe I've made a tripleEmptyNavigationLink modifier which I've stuck at the end of all my views. It's solving the popping behaviour but I'm still getting the 'Unable to present' warnings. Would love to know if anyone has anything better than this!
import SwiftUI
struct TripleEmptyNavigationLink: View {
var body: some View {
VStack {
NavigationLink(destination: EmptyView()) {EmptyView()}
NavigationLink(destination: EmptyView()) {EmptyView()}
NavigationLink(destination: EmptyView()) {EmptyView()}
}
}
}
struct TripleEmptyNavigationLinkBackground: ViewModifier {
func body(content: Content) -> some View {
content
.background(TripleEmptyNavigationLink())
}
}
extension View {
func tripleEmptyNavigationLink()-> some View {
self.modifier(TripleEmptyNavigationLinkBackground())
}
}
usage:
MyView()
.tripleEmptyNavigationLink()

In Xcode13 beta still has this issue.
So far solution:
1、Wrap NavigationLink with List or Form:
List {
NavigationLink(destination: Text("1")) {
Text("1")
}
NavigationLink(destination: Text("2")) {
Text("2")
}
NavigationLink(destination: Text("3")) {
Text("3")
}
}
2、Or Use one NavigationLink, and create destination view from func:
struct TaskIndexPage: View {
func buildView() -> some View {
// return you destination
switch self.option {
case 1:
return Text("\(option)")
default:
return Text("\(option)")
}
}
#State private var showDetail: Bool = false
#State private var option: Int = 0
var body: some View {
VStack {
Button {
showDetail = true
option = 1
} label: { Text("button 1") }
Button {
showDetail = true
option = 2
} label: { Text("button 2") }
Button {
showDetail = true
option = 3
} label: { Text("button 3") }
}
// handle navigating
NavigationLink(destination: self.buildView(), isActive: $showDetail) {}.opacity(0)
}
}

Adding a NavigationLink with an empty view didn't work for me. I solved my issue removing all NavigationLinks from the ForEach and using a single one to control the navigation to the detail view, a tap gesture and 2 state variables to keep track on what is being tapped on.
The example broken code and fix can be found at Paul Hudson's site.
https://www.hackingwithswift.com/forums/swiftui/unable-to-present-please-file-a-bug/7901/8237
Below is the complete working version
import SwiftUI
struct NavigationViewOptions {
enum OptionType { case main, optional }
typealias Option = (id: UUID, value: String, type: Self.OptionType)
static var options: [Option] = [
(UUID(), "Option 1", .main),
(UUID(), "Option 2", .optional),
(UUID(), "Option 3", .main),
(UUID(), "Option 4", .main),
(UUID(), "Option 5", .optional),
]
static func buildView(for option: Option) -> some View {
switch option.type {
case .main:
return Text("Main Option selected\n\(option.value)").font(.title).fontWeight(.bold)
case .optional:
return Text("Optional Option selected\n\(option.value)").font(.title3).italic().fontWeight(.medium)
}
}
}
struct NavigationViewWorking: View {
// State variables to leep track of what option has been tapped on and when to navigate to new view
#State private var selectedOption: NavigationViewOptions.Option = (id:UUID(),"",.main)
#State private var showDetail: Bool = false
var body: some View {
NavigationView {
ScrollView{
VStack (alignment:.leading) {
Text("NAVIGATION FIX FOR:\nUnable to present. Please file a bug.")
.padding(.bottom, 40)
ForEach(NavigationViewOptions.options, id: \.id) { option in
Text(option.value)
.font(.title)
.padding(.vertical, 10)
.foregroundColor(.accentColor) // same color as navigationLink
// handle tap on option
.onTapGesture {
selectedOption = option
showDetail = true
}
}
Spacer()
NavigationLink("", destination: NavigationViewOptions.buildView(for: selectedOption), isActive: $showDetail)
.opacity(0)
}
.navigationTitle("Options")
}
// INITIAL DETAIL VIEW
Text("Select option from the left")
}
}
}

For me the correct answer didn't work.
It showed Unable to present-message and then required view was pushed and poped out back quickly.
While playing around I found a working solution. I keep NotificationLink's without label set as a plain List items.
NavigationView {
ZStack {
List {
NavigationLink(isActive: $isFirstViewPresented,
destination: firstView,
label: EmptyView.init)
NavigationLink(isActive: $isSecondViewPresented,
destination: secondView,
label: EmptyView.init)
}
.listStyle(.plain)
//...
Button("Show first view") { isFirstViewPresented.toggle() }
Button("Show second view") { isSecondViewPresented.toggle() }
}
}
Don't forget to wrap active-properties with #State.
It also has some benefits as for me (all the navigation links are placed at the top of the view-getter and I don't need to look for it through all the code.

I could never find a reliable solution to this horrible bug. So I decided to create a custom NavigationLink, https://gist.github.com/Arutyun2312/a0dab7eecaa84bde99c435fecae76274. This works way better than expected, because all swiftui related functions continue working as usual. Seems like the bug is specifically with NavigationLink.
struct NavigationLink: View {
fileprivate init<T: View>(body: T) {
self.body = .init(body)
}
let body: AnyView
}
private struct NavigationLinkImpl<Destination: View, Label: View>: View {
let destination: () -> Destination?
#State var isActive = false
#ViewBuilder let label: () -> Label
var body: some View {
NavigationLinkImpl1(destination: destination, isActive: $isActive, label: label)
}
}
private struct NavigationLinkImpl1<Destination: View, Label: View>: View {
let destination: () -> Destination
#Binding var isActive: Bool
#ViewBuilder let label: () -> Label
#State var model = Model()
var body: some View {
Button(action: action, label: label)
.introspectNavigationController(customize: handle)
.id(isActive)
}
func handle(nav: UINavigationController) {
if isActive {
if model.destination == nil {
let dest = UIHostingController<Destination>(rootView: destination())
nav.pushViewController(dest, animated: true)
model.destination = dest
}
} else {
if let dest = model.destination {
if let i = nav.viewControllers.lastIndex(of: dest) {
nav.setViewControllers(.init(nav.viewControllers.prefix(i + 1)), animated: true)
}
model.destination = nil
}
}
if isActive != model.contains(nav: nav) { // detect pop
isActive = model.contains(nav: nav)
}
}
final class Model {
var destination: UIHostingController<Destination>?
func contains(nav: UINavigationController) -> Bool { destination.map { nav.viewControllers.contains($0) } ?? false }
}
func action() { isActive = true }
}
extension NavigationLink {
init<Destination: View, Label: View>(destination: #autoclosure #escaping () -> Destination, #ViewBuilder label: #escaping () -> Label) {
self.init(body: NavigationLinkImpl(destination: destination, label: label))
}
init<Destination: View, Label: View>(destination: #autoclosure #escaping () -> Destination, isActive: Binding<Bool>, #ViewBuilder label: #escaping () -> Label) {
self.init(body: NavigationLinkImpl1(destination: destination, isActive: isActive, label: label))
}
init<Destination: View>(_ text: String, destination: #autoclosure #escaping () -> Destination, isActive: Binding<Bool>) {
self.init(destination: destination(), isActive: isActive) { Text(text) }
}
init<Destination: View>(_ text: String, destination: #autoclosure #escaping () -> Destination) {
self.init(destination: destination()) { Text(text) }
}
}
Put this in a file, and your existing NavigationLinks will work just fine. Tested in ios 14 and 15

Like anybody else on iOS 14.5.1 my application is hit by this awful bug. I have more than 3 NavigationLinks in the page, and I was not lucky to modify the numbers of the NavigationLinks (by adding a dummy NavigationLink) to get the correct behaviour.
A workaround that is Okay for me is to add a NavigationLink conditionally into the view.
Instead of:
var body: some View {
NavigationLink(destination: AnotherView(), isActive: $someCondition) { EmptyView() }
}
I have this:
var body: some View {
if someCondition {
NavigationLink(destination: AnotherView(), isActive: $someCondition) { EmptyView() }
}
}
The behaviour is not exactly the same, as you lose some navigation animation candy, but at least you have a working application again with relatively easy to understand fix.
You can also short-circuit it to 14.5 only, and normal behaviour elsewhere:
/// Assumes this gets fixed by Apple until 14.6 is out
var onIOS14_5: Bool {
let systemVersion = UIDevice.current.systemVersion
return systemVersion.starts(with: "14.5")
}
var body: some View {
if !onIOS14_5 || someCondition {
NavigationLink(destination: AnotherView(), isActive: $someCondition) { EmptyView() }
}
}
Perhaps this helps someone and lets all hope Apple will fix this embarrasing bug. Now I want my half day back.

In my case, the NavigationLink didn't work because of an .onTapGesture I added to dismiss the keyboard.

I got exactly the same problem.
my code:
class NavigationManager: ObservableObject {
static let shared: NavigationManager = {
return NavigationManager()
}()
#Published var showingMain: Bool
#Published var showingSub: Bool
#Published var content: AnyView
init() {
showingMain = false
showingSub = false
content = AnyView(EmptyView())
}
func forward<T:View>(content: #escaping () -> T ) {
showView()
self.content = AnyView(content())
}
private func showView() {
if !showingMain,!showingSub {
showingMain = true
} else if showingMain,!showingSub {
showingSub = true
} else if !showingMain,showingSub {
showingMain = true
}
}
}
struct NavigationLinkGroup: View {
#EnvironmentObject var navigationManager: NavigationManager
var body: some View {
Group {
NavigationLink(destination: navigationManager.content, isActive: $navigationManager.showingMain) {EmptyView()}
NavigationLink(destination: navigationManager.content, isActive: $navigationManager.showingSub) {EmptyView()}
}
}
}
struct ContentView: View {
var body: some View {
NavigationView {
NavigationLinkGroup()
}
}
}
https://github.com/Ftrybe/CustomBackButtonOfSwiftUIApp/tree/master/CustomBackButtonOfSwiftUI

It seems that if there's more than one NavigationLink in NavigationView, this bug will be filed.
Here's my solution.
import SwiftUI
enum MyLink {
case myView1
case myView2
}
struct MyView1: View {
var body: some View {
Text("MyView1")
}
}
struct MyView2: View {
var body: some View {
Text("MyView2")
}
}
struct ExampleView: View {
#State var currentLink: MyLink = .myView1
#State var isLinkViewShow: Bool = false
func getLinkView(_ myLink: MyLink) -> some View {
if myLink == .myView1 {
return AnyView(MyView1())
} else {
return AnyView(MyView2())
}
}
var body: some View {
NavigationView {
VStack {
NavigationLink("",
destination: getLinkView(currentLink),
isActive: $isLinkViewShow)
// Press to navigate to MyView1
Button(action: {
currentLink = .myView1
isLinkViewShow = true
}) {
Text("To MyView1")
}
// Press to navigate to MyView2
Button(action: {
currentLink = .myView2
isLinkViewShow = true
}) {
Text("To MyView2")
}
}
}
}
}

Adding a delay gets auto-navigation working again.
NavigationLink(destination: PopupView(),isActive: $showView){}
&
.onAppear {
if (test()){
DispatchQueue.main.asyncAfter(deadline: .now() + 1) {showView = true}
}
}

Related

Add NavigationLink to Custom designed button in Swift UI

I am trying to add NavigationLink inside NavigationView in which there is a custom designed button.
I want to navigate on that button tap but NavigationLink code gives compilation error. it requires localisedTitle which I don't want to display and also tried to give Custom button in place of label but not working. Any help would be appreciated
Here is my code! I am using Xcode 13.3.1
#State private var isShowingSignupView = false
var body: some View {
NavigationView {
VStack {
Spacer()
VStack(alignment: .center, spacing: 12) {
AppTextField(Constants.Email, text: $email)
AppTextField(Constants.Password, text: $password, isSecure: $isSecure, leftImage: "lock",rightImage: Image(systemName: "eye.fill"), rightSelectedImage: Image(systemName: "eye.slash.fill"))
AppButtonText(title: Constants.ForgotPassword) {
debugPrint("Forgot Password tapped")
}
.frame(maxWidth: .infinity, maxHeight: 20, alignment: .trailing)
AppButton(title: Constants.Login) {
}
}
Spacer()
NavigationLink($isShowingSignupView, destination: Signup) {
AppButtonText(title: Constants.SignUp) {
isShowingSignupView = true
}
}
}
.padding()
}
.navigationTitle("Login")
}
**ERROR:-
Cannot convert value of type 'Signup.Type' to expected argument type '() -> Destination'
Generic parameter 'Destination' could not be inferred**
**I have also tried after replacing this **
NavigationLink(destination: Signup()) {
AppButtonText(title: Constants.SignUp) {
isShowingSignupView = true
}
}
Which just removed error but does not navigate on new screen
Hey there!
I got the issue and sollution to it.
Actually above code was almost correct but the problem was in Custom Button view action which was not getting triggered due to simultaneousGesture added in it for functionality
struct AppButtonText: View {
var title: String
#State var action: () -> ()
#State private var isPressed = false
var body: some View {
Text(title)
.foregroundColor(isPressed ? Color.red.opacity(0.5) : Color.red)
.background(Color.clear)
.padding(.vertical, 0)
.font(.body)
.simultaneousGesture(
DragGesture(minimumDistance: 0)
.onChanged({ _ in
isPressed = true
})
.onEnded({ _ in
isPressed = false
action() `THIS LINE WAS NOT ADDED BEFORE`
})
)
}
}
And this below line was having no issue
NavigationLink($isShowingSignupView, destination: Signup) {
AppButtonText(title: Constants.SignUp) {
isShowingSignupView = true
}
}
THANKS ALL FOR YOUR VALUABLE REPLIES
You need to use NavigationLink(destination: { Signup() })
Also since you are using custom Button instead of NavigationLink it's better use isActive property:
NavigationLink("Signup", isActive: $isShowingSignupView) {
Signup()
}
AppButtonText(title: Constants.SignUp) {
isShowingSignupView = true
}
You can just do it like this. Note that you need to initialize when using a view struct, like Signup().
#State private var isShowingSignupView = false
struct Signup: View {
var body: some View {
Text("Your view contents here")
}
}
var signup: some View {
Text("Your view contents here")
}
var body: some View {
NavigationView {
VStack {
// Using a view
NavigationLink(isActive: $isShowingSignupView) {
signup
} label: {
AppButtonText(title: Constants.SignUp) {
isShowingSignupView = true
}
}
// Using a view struct
NavigationLink(isActive: $isShowingSignupView) {
Signup()
} label: {
AppButtonText(title: Constants.SignUp) {
isShowingSignupView = true
}
}
}
}
}

SwiftUI NavigationLink highlight staying highlighted after returning to previous view

I have a series of views in SwiftUI. One is a "Menu View" which consists of a List of NavigationLinks wrapped in a NavigationView.
The code is as follows.
var body: some View {
NavigationView {
List {
HStack {
NavigationLink(destination: History(), isActive: $isHistoryViewActive) {
Image(systemName: "clock")
Text("History")
}
}
HStack {
NavigationLink(destination: Settings(), isActive: $isSettingsActive) {
Image(systemName: "gear")
Text("Settings")
}
}
HStack {
Image(systemName: "info.circle.fill")
Button(action: {
...
}) {
Text("My Button")
}
}
}
}
}
The Settings view is as follows
var body: some View {
List {
...
Section(header: "Background Music") {
Toggle("Play", isOn: $isBackGroundMusicOn)
}
Section(header: "Voice Setting") {
HStack {
NavigationLink(destination: VoiceList() {
Text(self.voiceNames[self.selectedVoice])
}
}
}
}
And lastly, the VoiceList view is as follows:
var body: some View {
List {
ForEach(0 ..< VoiceList.voiceNames.count) {voiceIndex in
HStack {
Button(action: {
voiceChanged(selectedVoice: voiceIndex)
}){
Text(VoiceList.voiceNames[voiceIndex])
}
Spacer()
Image(systemName: "checkmark")
.frame(alignment: .trailing)
.foregroundColor(.blue)
.isHidden(hidden: voiceIndex != selectedVoice)
}
}
}
}
The problem that I am having is that when the app returns from the VoiceList view to the Settings view, the NavigationLink remains highlighted, as if it is still active, as shown in the attached screenshot. I honestly have no idea what may be causing this. Any ideas or insights are greatly appreciated.
You can use a onReceive action on the List:
List {
…
}.onReceive(NotificationCenter.default.publisher(for: UITableView.selectionDidChangeNotification)) {
guard let tableView = $0.object as? UITableView,
let selectedRow = tableView.indexPathForSelectedRow else { return }
tableView.deselectRow(at: selectedRow, animated: true)
}
This will deselect the selected row.
Credit for the initial idea for this workaround goes to Pivaisan (from this Apple Developer thread).
I had the same problem working with List, to solve this i use: UITableViewCell.appearance().selectionStyle = .none, but as you can expected you will not have the selection aspect, so the right way is try to store the state of selection and clean before leave the screen but in my trys i have no idea how to do that.
Example:
struct YourApp: App {
init() {
UITableView.appearance().backgroundColor = .clear
UITableViewCell.appearance().selectionStyle = .none
}
var body: some Scene {
WindowGroup {
ContentView()
}
}
}

SwiftUI - View disappears if animated

I am building a custom segmented control. This is the code that I have written.
struct SegmentedControl: View {
private var items: [String] = ["One", "Two", "Three"]
#Namespace var animation:Namespace.ID
#State var selected: String = "One"
var body: some View {
ScrollView(.horizontal) {
HStack {
ForEach(items, id: \.self) { item in
Button(action: {
withAnimation(.spring()){
self.selected = item
}
}) {
Text(item)
.font(Font.subheadline.weight(.medium))
.foregroundColor(selected == item ? .white : .accentColor)
.padding(.horizontal, 25)
.padding(.vertical, 10)
.background(zStack(item: item))
}
}
} .padding()
}
}
private func zStack(item: String) -> some View {
ZStack{
if selected == item {
Color.accentColor
.clipShape(Capsule())
.matchedGeometryEffect(id: "Tab", in: animation)
} else {
Color(.gray)
.clipShape(Capsule())
}}
}
}
A control is Blue when it is selected.
It works as expected most of the time like in the following GIF.
However, sometimes if you navigate back and forth very fast, the Color.accentColor moves off screen and disappears as you see in the following GIF. I have used a lot of time but could not fix it.
Sometimes, I get this error.
Multiple inserted views in matched geometry group Pair<String,
ID>(first: "Tab", second: SwiftUI.Namespace.ID(id: 248)) have `isSource:
true`, results are undefined.
Info, It is easier to test it on a physical device rather than a simulator.
Update
This is my all codde including the ContentView and the Modal.
struct ContentView: View {
#State private var isPresented: Bool = false
var body: some View {
NavigationView {
VStack {
Button(action: {
self.isPresented.toggle()
}, label: {
Text("Button")
})
}
}
.sheet(isPresented: $isPresented, content: {
ModalView()
})
}
}
struct ModalView: View {
var body: some View {
NavigationView {
NavigationLink(
destination: TabbarView(),
label: {
Text("Navigate")
})
}
}
}
struct TabbarView: View {
private var items: [String] = ["One", "Two", "Three"]
#Namespace var animation:Namespace.ID
#State var selected: String = "" // change here
var body: some View {
ScrollView(.horizontal) {
HStack {
ForEach(items, id: \.self) { item in
Button(action: {
withAnimation{
self.selected = item
}
}) {
Text(item)
.font(Font.subheadline.weight(.medium))
.foregroundColor(selected == item ? .white : .accentColor)
.padding(.horizontal, 25)
.padding(.vertical, 10)
.background(zStack(item: item))
}
}
} .padding()
}
.onAppear { self.selected = "One" } // add this
}
private func zStack(item: String) -> some View {
ZStack{
if selected == item {
Color.accentColor
.clipShape(Capsule())
.matchedGeometryEffect(id: "Tab", in: animation)
} else {
Color(.gray)
.clipShape(Capsule())
}}
}
}

SwiftUI - NavigationLink cell in a Form stays highlighted after detail pop

In iOS 14, it appears that NavigationLinks do not become deselected after returning in a Form context.
This is also true for Form Pickers and anything else that causes the presentation of another View from a list (giving a highlight context to the presenting cell).
I didn't notice this behaviour in iOS 13.
Is there a way to 'deselect' the highlighted row once the other view is dismissed?
Example code:
struct ContentView: View {
var body: some View {
Form {
NavigationLink(destination: Text("Detail")) {
Text("Link")
}
}
}
}
(Different) Example visual:
In my case this behaviour appeared when using any Viewcontent (e.g. Text(), Image(), ...) between my NavigationView and List/Form.
var body: some View {
NavigationView {
VStack {
Text("This text DOES make problems.")
List {
NavigationLink(destination: Text("Doesn't work correct")) {
Text("Doesn't work correct")
}
}
}
}
}
Putting the Text() beneath the List does not make any problems:
var body: some View {
NavigationView {
VStack {
List {
NavigationLink(destination: Text("Does work correct")) {
Text("Does work correct")
}
}
Text("This text doesn't make problems.")
}
}
}
This is definitely a XCode 12 bug. As more people report this, as earlier it gets resolved.
I have also run into this issue and believed I found the root cause in my case.
In my case I had.a structure like the following:
struct Page1View: View {
var body: some View {
NavigationView {
List {
NavigationLink("Page 2", destination: Page2View())
}
.listStyle(GroupedListStyle())
.navigationBarTitle("Page 1")
}
}
}
struct Page2View: View {
var body: some View {
List {
NavigationLink("Page 3", destination: Text("Page 3"))
}
.listStyle(GroupedListStyle())
.navigationBarTitle("Page 2")
}
}
This issue would occur on the NavigationLink to Page 3. In the console output this error was showing when that link was used:
2021-02-13 16:41:00.599844+0000 App[59157:254215] [Assert] displayModeButtonItem is internally managed and not exposed for DoubleColumn style. Returning an empty, disconnected UIBarButtonItem to fulfill the non-null contract.
I discovered that I needed to apply .navigationViewStyle(StackNavigationViewStyle()) to the NavigationView and this solved the problem.
I.e.
struct Page1View: View {
var body: some View {
NavigationView {
List {
NavigationLink("Page 2", destination: Page2View())
}
.listStyle(GroupedListStyle())
.navigationBarTitle("Page 1")
}
.navigationViewStyle(StackNavigationViewStyle())
}
}
Been fighting this issue half day today and came to this post that helped me to understand that issue appears if Text, Button or something else placed between NavigationView and in my case List. And I found solution that worked for me. Just add .zIndex() for the item. .zIndex() must be higher than for List Tried with Xcode 12.5.
var body: some View {
NavigationView {
VStack {
Text("This text DOES make problems.")
.zIndex(1.0)
List {
NavigationLink(destination: Text("Doesn't work correct")) {
Text("Doesn't work correct")
}
}
}
}
}
I did a bit more tinkering, it turns out this was caused due by having the UIHostingController being nested in a UINavigationController and using that navigation controller. Changing the navigation stack to use a SwiftUI NavigationView instead resolved this issue.
Similar to what #pawello2222 says in the question comments, I think the underlying cause is something to do with SwiftUI not understanding the proper navigation hierarchy when the external UINavigationController is used.
This is just one instance where this is fixed though, I'm still experiencing the issue in various other contexts depending on how my view is structured.
I've submitted an issue report FB8705430 to Apple, so hopefully this is fixed sometime soon.
Before (broken):
struct ContentView: View {
var body: some View {
Form {
NavigationLink(destination: Text("test")) {
Text("test")
}
}
}
}
// (UIKit presentation context)
let view = ContentView()
let host = UIHostingController(rootView: view)
let nav = UINavigationController(rootViewController: host)
present(nav, animated: true, completion: nil)
After (working):
struct ContentView: View {
var body: some View {
NavigationView {
Form {
NavigationLink(destination: Text("test")) {
Text("test")
}
}
}
}
}
// (UIKit presentation context)
let view = ContentView()
let host = UIHostingController(rootView: view)
present(host, animated: true, completion: nil)
This is definitely a bug in List, for now, my work-around is refreshing the List by changing the id, like this:
struct YourView: View {
#State private var selectedItem: String?
#State private var listViewId = UUID()
var body: some View {
List(items, id: \.id) {
NavigationLink(destination: Text($0.id),
tag: $0.id,
selection: $selectedItem) {
Text("Row \($0.id)")
}
}
.id(listViewId)
.onAppear {
if selectedItem != nil {
selectedItem = nil
listViewId = UUID()
}
}
}
}
I made a modifier based on this that you can use:
struct RefreshOnAppearModifier<Tag: Hashable>: ViewModifier {
#State private var viewId = UUID()
#Binding var selection: Tag?
func body(content: Content) -> some View {
content
.id(viewId)
.onAppear {
if selection != nil {
viewId = UUID()
selection = nil
}
}
}
}
extension View {
func refreshOnAppear<Tag: Hashable>(selection: Binding<Tag?>? = nil) -> some View {
modifier(RefreshOnAppearModifier(selection: selection ?? .constant(nil)))
}
}
use it like this:
List { ... }
.refreshOnAppear(selection: $selectedItem)
I managed to solve it by adding ids to the different components of the list, using binding and resetting the binding on .onDisappear
struct ContentView: View {
#State var selection: String? = nil
var body: some View {
NavigationView {
VStack {
Text("Hello, world!")
.padding()
List {
Section {
NavigationLink( destination: Text("Subscreen1"), tag: "link1", selection: $selection ) {
Text("Subscreen1")
}.onDisappear {
self.selection = nil
}
NavigationLink( destination: Text("Subscreen2"), tag: "link2", selection: $selection ) {
Text("Subscreen2")
}.onDisappear {
self.selection = nil
}
}.id("idSection1")
}
.id("idList")
}
}
}
}
I've also run into this issue and it seemed related to sheets as mentioned here.
My solution was to swizzle UITableView catch selections, and deselect the cell. The code for doing so is here. Hopefully this will be fixed in future iOS.
Adding .navigationViewStyle(StackNavigationViewStyle()) to NavigationView fixed it for me.
Suggested in this thread: https://developer.apple.com/forums/thread/660468
This is my solution to this issue.
// This in a stack in front of list, disables large navigation title from collapsing by disallowing list from scrolling on top of navigation title
public struct PreventCollapseView: View {
#State public var viewColor: Color?
public init(color: Color? = nil) {
self.viewColor = color
}
public var body: some View {
Rectangle()
.fill(viewColor ?? Color(UIColor(white: 0.0, alpha: 0.0005)))
.frame(minWidth: 0, maxWidth: .infinity, minHeight: 0, maxHeight: 1)
}
}
// handy modifier..
extension List {
public func uncollapsing(_ viewUpdater: Bool) -> some View {
VStack(spacing: 0.0) {
Group {
PreventCollapseView()
self
}.id(viewUpdater)
}
}
}
struct TestView: View {
#State var updater: Bool = false
var body: some View {
List {
Text("Item one")
Text("Item two")
Text("Manually refresh")
.onTapGesture { DispatchQueue.main.async { updater.toggle() } }
.onAppear { print("List was refreshed") }
}
.uncollapsing(updater)
.clipped()
.onAppear { DispatchQueue.main.async { updater.toggle() }} // Manually refreshes list always when re-appearing/appearing
}
}
Add a NavigationView, configure for largeTitle, and embed TestView and it's all set. Toggle updater to refresh.
Having the same Problem. The weird thing is, that the exact same code worked in iOS13.
I'm having this issue with a simple list:
struct TestList: View {
let someArray = ["one", "two", "three", "four", "five"]
var body: some View {
List(someArray, id: \.self) { item in
NavigationLink(
destination: Text(item)) {
Text(item)
}.buttonStyle(PlainButtonStyle())
}.navigationBarTitle("testlist")
}
}
This is embedded in:
struct ListControllerView: View {
#State private var listPicker = 0
var body: some View {
NavigationView{
Group{
VStack{
Picker(selection: $listPicker, label: Text("Detailoverview")) {
Text("foo").tag(0)
Text("bar").tag(1)
Text("TestList").tag(2)
}
This is inside a Tabbar.
This is the workaround I've been using until this List issue gets fixed. Using the Introspect library, I save the List's UITableView.reloadData method and call it when it appears again.
import SwiftUI
import Introspect
struct MyView: View {
#State var reload: (() -> Void)? = nil
var body: some View {
NavigationView {
List {
NavigationLink("Next", destination: Text("Hello"))
}.introspectTableView { tv in
self.reload = tv.reloadData
}.onAppear {
self.reload?()
}
}
}
}

Show leading navigationBarItems button only if shown as a modal

I have a view that can be shown either as a modal, or simply pushed onto a navigation stack. When it's pushed, it has the back button in the top left, and when it's shown as a modal, I want to add a close button (many of my testers were not easily able to figure out that they could slide down the modal and really expected an explicit close button).
Now, I have multiple problems.
How do I figure out if a View is shown modally or not? Or alternatively, if it's not the first view on a navigation stack? In UIKit there are multiple ways to easily do this. Adding a presentationMode #Environment variable doesn't help, because its isPresented value is also true for pushed screens. I could of course pass in a isModal variable myself but it seems weird that's the only way?
How do I conditionally add a leading navigationBarItem? The problem is that if you give nil, even the default back button is hidden.
Code to copy and paste into Xcode and play around with:
import SwiftUI
struct ContentView: View {
#State private var showModal = false
var body: some View {
NavigationView {
VStack(spacing: 20) {
Button("Open modally") {
self.showModal = true
}
NavigationLink("Push", destination: DetailView(isModal: false))
}
.navigationBarTitle("Home")
}
.sheet(isPresented: $showModal) {
NavigationView {
DetailView(isModal: true)
}
}
}
}
struct DetailView: View {
#Environment(\.presentationMode) private var presentationMode
let isModal: Bool
var body: some View {
Text("Hello World")
.navigationBarTitle(Text("Detail"), displayMode: .inline)
.navigationBarItems(leading: closeButton, trailing: deleteButton)
}
private var closeButton: some View {
Button(action: { self.presentationMode.wrappedValue.dismiss() }) {
Image(systemName: "xmark")
.frame(height: 36)
}
}
private var deleteButton: some View {
Button(action: { print("DELETE") }) {
Image(systemName: "trash")
.frame(height: 36)
}
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
If I change closeButton to return an optional AnyView? and then return nil when isModal is false, I don't get a back button at all. I also can't call navigationBarItems twice, once with a leading and once with a trailing button, because the latter call overrides the first call. I'm kinda stuck here.
Okay, I managed it. It's not pretty and I am very much open to different suggestions, but it works 😅
import SwiftUI
extension View {
func eraseToAnyView() -> AnyView {
AnyView(self)
}
public func conditionalNavigationBarItems(_ condition: Bool, leading: AnyView, trailing: AnyView) -> some View {
Group {
if condition {
self.navigationBarItems(leading: leading, trailing: trailing)
} else {
self
}
}
}
}
struct ContentView: View {
#State private var showModal = false
var body: some View {
NavigationView {
VStack(spacing: 20) {
Button("Open modally") {
self.showModal = true
}
NavigationLink("Push", destination: DetailView(isModal: false))
}
.navigationBarTitle("Home")
}
.sheet(isPresented: $showModal) {
NavigationView {
DetailView(isModal: true)
}
}
}
}
struct DetailView: View {
#Environment(\.presentationMode) private var presentationMode
let isModal: Bool
var body: some View {
Text("Hello World")
.navigationBarTitle(Text("Detail"), displayMode: .inline)
.navigationBarItems(trailing: deleteButton)
.conditionalNavigationBarItems(isModal, leading: closeButton, trailing: deleteButton)
}
private var closeButton: AnyView {
Button(action: { self.presentationMode.wrappedValue.dismiss() }) {
Image(systemName: "xmark")
.frame(height: 36)
}.eraseToAnyView()
}
private var deleteButton: AnyView {
Button(action: { print("DELETE") }) {
Image(systemName: "trash")
.frame(height: 36)
}.eraseToAnyView()
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
I don't see any trouble, just add Dismiss button to your navigation bar. You only have to rearrange your View hierarchy and there is no need to pass any binding to your DetailView
import SwiftUI
struct DetailView: View {
var body: some View {
Text("Detail View")
}
}
struct ContentView: View {
#State var sheet = false
var body: some View {
NavigationView {
VStack(spacing: 20) {
Button("Open modally") {
self.sheet = true
}
NavigationLink("Push", destination: DetailView())
}.navigationBarTitle("Home")
}
.sheet(isPresented: $sheet) {
NavigationView {
DetailView().navigationBarTitle("Title").navigationBarItems(leading: Button(action: {
self.sheet.toggle()
}, label: {
Text("Dismiss")
}))
}
}
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
You still can dismiss it with swipe down, you can add some buttons (as part of DetailView declaration) ... etc.
When pushed, you have default back button, if shown modaly, you have dismiss
button indeed.
UPDATE (based od discussion)
.sheet(isPresented: $sheet) {
NavigationView {
GeometryReader { proxy in
DetailView().navigationBarTitle("Title")
.navigationBarItems(leading:
HStack {
Button(action: {
self.sheet.toggle()
}, label: {
Text("Dismiss").padding(.horizontal)
})
Color.clear
Button(action: {
}, label: {
Image(systemName: "trash")
.imageScale(.large)
.padding(.horizontal)
})
}.frame(width: proxy.size.width)
)
}
}
}
finally I suggest you to use
extension View {
#available(watchOS, unavailable)
public func navigationBarItems<L, T>(leading: L?, trailing: T) -> some View where L : View, T : View {
Group {
if leading != nil {
self.navigationBarItems(leading: leading!, trailing: trailing)
} else {
self.navigationBarItems(trailing: trailing)
}
}
}
}
Whenever we provide .navigationBarItems(leading: _anything_), ie anything, the standard back button has gone, so you have to provide your own back button conditionally.
The following approach works (tested with Xcode 11.2 / iOS 13.2)
.navigationBarItems(leading: Group {
if isModal {
closeButton
} else {
// custom back button here calling same dismiss
}
}, trailing: deleteButton)
Update: alternate approach might be as follows (tested in same)
var body: some View {
VStack {
if isModal {
Text("Hello")
.navigationBarItems(leading: closeButton, trailing: deleteButton)
} else {
Text("Hello")
.navigationBarItems(trailing: deleteButton)
}
}
.navigationBarTitle("Test", displayMode: .inline)
}

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