I am trying to create an actionSheet that opens a modal to save to a view. Currently, I can only get one of the buttons in the actionSheet to open to the modal. How can I rewrite the .sheet code to do this? Thanks.
#State var showActionSheet = false
#State var showAddActivityPopup = false
#State var showAddDayPopup = false
var body: some View {
Button(action: {
self.showActionSheet = true
}) {
Text("Show Action Sheet")
}
.actionSheet(isPresented: $showActionSheet, content: actionSheet)
.sheet(isPresented: $showAddDayPopup, onDismiss: {
print(self.showActionSheet)
}) {
AddDayPopup(message: "Add Day")
}
.sheet(isPresented: $showAddActivityPopup, onDismiss: {
print(self.showActionSheet)
}) {
AddActivityPopup(message: "Add Activity")
}
}
private func actionSheet() -> ActionSheet {
let button1 = ActionSheet.Button.default(Text("Add Day")) {
self.showActionSheet = false
self.showAddDayPopup = true
}
let button2 = ActionSheet.Button.default(Text("Add Activity")) {
self.showActionSheet = false
self.showAddActivityPopup = true
}
let actionSheet = ActionSheet(title: Text("What would you like to add?"),
message: nil,
buttons: [button1, button2, .cancel()])
return actionSheet
}
}
Related
I am trying to create an alert presenter to control alerts using SwiftUI.
The goal is to use a simple top level function to present an alert.
The following is my code:
First, create an AlertPresenter which has a present and dismiss alert function.
class AlertPresenter: ObservableObject{
#Published var tittle: String
#Published var isPresented: Bool
#Published var action: //Issue: I want to pass a view in this property, a optional View will be better
#Published var message: //Issue: I want to pass a view in this property
init() {
self.tittle = ""
self.isPresented = false
self.action = EmptyView()
self.message = EmptyView()
}
//Issue: I want to pass SwiftUI View as a function parameter
func present(tittle: String, message: String, action: #escaping () -> View, message: #escaping () -> View){
self.tittle = tittle
self.isPresented = true
self.action = action
self.message = message
}
func dismiss(){
self.tittle = ""
self.isPresented = false
self.action = EmptyView()
self.message = EmptyView()
}
}
We create the AlertPresenter, and pass it as an EnvironmentObject, and then connect the AlertPresenter with the parent view
struct ParentView: View{
#EnvironmentObject var alertPresenter: AlertPresenter = AlertPresenter()
var body: some View{
ChildView()
.environmentObject(alertPresenter)
.alert(tittle: alertPresenter.tittle, isPresented: $alertPresenter.isPresented){
alertPresenter.action
} message: {
alertPresenter.message
} //this function is alert(_:isPresented:actions:message:) available from iOS15.0+
}
}
At the end, I want to use a simple top level function to present and dismiss an alert:
Button("Present Alert"){
alertPresenter.present(tittle: "This is the alert tittle"){
Button("OK"){
//dismiss alert
alertPresenter.dismiss()
}
} message: {
Text("This is the alert message")
}
}
Thanks :)
What you CAN do is reduce the inputs to strings to display (which obviously reduces the flexibility):
class AlertPresenter: ObservableObject {
#Published var title: String
#Published var isPresented: Bool
#Published var buttonTitle: String
#Published var message: String
init() {
self.title = ""
self.isPresented = false
self.buttonTitle = "OK"
self.message = ""
}
func present(title: String, buttonTitle: String, message: String) {
self.title = title
self.isPresented = true
self.buttonTitle = buttonTitle
self.message = message
}
func dismiss(){
self.title = ""
self.isPresented = false
self.buttonTitle = "OK"
self.message = ""
}
}
struct ContentView: View {
#StateObject var alertPresenter = AlertPresenter()
var body: some View{
ChildView()
.environmentObject(alertPresenter)
.alert(alertPresenter.title, isPresented: $alertPresenter.isPresented) {
Button(alertPresenter.buttonTitle) { alertPresenter.dismiss() }
} message: {
Text(alertPresenter.message)
} //this function is alert(_:isPresented:actions:message:) available from iOS15.0+
}
}
struct ChildView: View {
#EnvironmentObject var alertPresenter: AlertPresenter
var body: some View{
Button("Present Alert"){
alertPresenter.present(title: "This is the alert title", buttonTitle: "Continue", message: "This is the alert message")
}
}
}
I want to immediately present the second alert view after click the dismiss button of the first alert view.
Button(action: {
self.alertIsVisible = true
}) {
Text("Hit Me!")
}
.alert(isPresented: $alertIsVisible) { () -> Alert in
return Alert(title: Text("\(title)"), message: Text("\n"), dismissButton:.default(Text("Next Round"), action: {
if self.score == 100 {
self.bonusAlertIsVisible = true
}
.alert(isPresented: $bonusAlertIsVisible) {
Alert(title: Text("Bonus"), message: Text("You've earned 100 points bonus!!"), dismissButton: .default(Text("Close")))}
})
)
However, it gives me an error of 'Alert.Button' is not convertible to 'Alert.Button?'
If I put this segment out of the scope of dismissButton, it will override the previous .alert.
So how can i do it, I just want to pop up the second alert after clicking the dismiss button of the first alert.
Thanks.
It appears (tested with Xcode 11.2):
While not documented, but it is not allowed to add more than one
.alert modifier in one view builder sequence - works only latest
It is not allowed to add .alert modifier to EmptyView, it does not work
at all
I've found alternate solution to proposed by #Rohit. In some situations, many alerts, this might result in simpler code.
struct TestTwoAlerts: View {
#State var alertIsVisible = false
#State var bonusAlertIsVisible = false
var score = 100
var title = "First alert"
var body: some View {
VStack {
Button(action: {
self.alertIsVisible = true
}) {
Text("Hit Me!")
}
.alert(isPresented: $alertIsVisible) {
Alert(title: Text("\(title)"), message: Text("\n"), dismissButton:.default(Text("Next Round"), action: {
if self.score == 100 {
DispatchQueue.main.async { // !! This part important !!
self.bonusAlertIsVisible = true
}
}
}))
}
Text("")
.alert(isPresented: $bonusAlertIsVisible) {
Alert(title: Text("Bonus"), message: Text("You've earned 100 points bonus!!"), dismissButton: .default(Text("Close")))
}
}
}
}
Please try below code.
Consecutively present two alert views using SwiftUI
struct ContentView: View {
#State var showAlert: Bool = false
#State var alertIsVisible: Bool = false
#State var bonusAlertIsVisible: Bool = false
var body: some View {
NavigationView {
Button(action: {
self.displayAlert()
}) {
Text("Hit Me!")
}
.alert(isPresented: $showAlert) { () -> Alert in
if alertIsVisible {
return Alert(title: Text("First alert"), message: Text("\n"), dismissButton:.default(Text("Next Round"), action: {
DispatchQueue.main.async {
self.displayAlert()
}
})
)
}
else {
return Alert(title: Text("Bonus"), message: Text("You've earned 100 points bonus!!"), dismissButton:.default(Text("Close"), action: {
self.showAlert = false
self.bonusAlertIsVisible = false
self.alertIsVisible = false
})
)
}
}
.navigationBarTitle(Text("Alert"))
}
}
func displayAlert() {
self.showAlert = true
if self.alertIsVisible == false {
self.alertIsVisible = true
self.bonusAlertIsVisible = false
}
else {
self.alertIsVisible = false
self.bonusAlertIsVisible = true
}
}
}
I am using UITabBarController in SwiftUI 2.0 and Xcode 12 but seems like Keyboard cases some unexpected behavior. As you can see from the below GIF, OnAppear of the other 2 tab's view called when the keyboard appears in the first tab. That is causing the issue as I have an API call written on appear.
Also, is there any way I can turn off the default view offset behavior of Xcode 12.
Here is my code of Content View.
struct ContentView: View {
#State private var index:Int = 0
var menuItems:[String] = ["Item 1", "Item 2", "Item 3"]
var body: some View {
NavigationView(content: {
ZStack{
MyTabView(selectedIndex: self.$index)
.view(item: self.item1) {
NewView(title: "Hello1").navigationBarTitle("")
.navigationBarHidden(true)
}
.view(item: self.item2) {
NewView(title: "Hello2").navigationBarTitle("")
.navigationBarHidden(true)
}
.view(item: self.item3) {
NewView(title: "Hello3").navigationBarTitle("")
.navigationBarHidden(true)
}
}.navigationBarHidden(true)
.navigationBarTitle("")
})
}
var item1:MyTabItem {
var item = MyTabItem()
item.imageName = "pencil.circle"
item.selectedImageName = "pencil.circle.fill"
return item
}
var item2:MyTabItem {
var item = MyTabItem()
item.imageName = "pencil.circle"
item.selectedImageName = "pencil.circle.fill"
return item
}
var item3:MyTabItem {
var item = MyTabItem()
item.imageName = "pencil.circle"
item.selectedImageName = "pencil.circle.fill"
return item
}
}
struct NewView:View {
#State var text:String = ""
var title:String
var body: some View {
VStack {
Spacer()
Text("Hello")
TextField(title, text: self.$text)
.textFieldStyle(RoundedBorderTextFieldStyle())
}.padding()
.onAppear {
debugPrint("OnApper \(self.title)")
}
}
}
and here is the code for CustomTabView.
class MyTabViewViewModel:ObservableObject {
var controllers: [UIViewController] = []
var tabItems:[MyTabItem] = []
}
struct MyTabItem {
var imageName:String = ""
var selectedImageName:String = ""
var hasDarkModeSupport:Bool = true
var image:UIImage?
var selectedImage:UIImage?
}
struct MyTabView: UIViewControllerRepresentable {
var viewModel:MyTabViewViewModel = MyTabViewViewModel()
#Binding var selectedIndex: Int
func makeUIViewController(context: Context) -> UITabBarController {
let tabBarController = UITabBarController()
tabBarController.viewControllers = self.viewModel.controllers
tabBarController.delegate = context.coordinator
tabBarController.selectedIndex = 0
let appearance = tabBarController.tabBar.standardAppearance
appearance.shadowImage = nil
appearance.shadowColor = nil
appearance.backgroundEffect = nil
tabBarController.tabBar.standardAppearance = appearance
tabBarController.tabBar.shadowImage = UIImage()
tabBarController.tabBar.backgroundImage = UIImage()
tabBarController.tabBar.layer.shadowPath = UIBezierPath(rect: tabBarController.tabBar.bounds).cgPath
tabBarController.tabBar.layer.shadowOffset = CGSize.init(width: 0, height: -3)
tabBarController.tabBar.layer.shadowRadius = 5
tabBarController.tabBar.layer.shadowColor = UIColor.black.cgColor
tabBarController.tabBar.layer.shadowOpacity = 0.25
tabBarController.tabBar.backgroundColor = UIColor.white
tabBarController.tabBar.barTintColor = UIColor.white
self.updateTabItems(forTabBarController: tabBarController)
return tabBarController
}
func updateUIViewController(_ tabBarController: UITabBarController, context: Context) {
tabBarController.selectedIndex = selectedIndex
self.updateTabItems(forTabBarController: tabBarController)
}
func makeCoordinator() -> Coordinator {
Coordinator(self)
}
func updateTabItems(forTabBarController tabBarController:UITabBarController) {
let isDarkModeEnable:Bool = tabBarController.traitCollection.userInterfaceStyle == .dark
for (index, tabItem) in self.viewModel.tabItems.enumerated() {
tabBarController.tabBar.items?[index].title = ""
if let image = tabItem.image {
tabBarController.tabBar.items?[index].image = image
if let selectedImage = tabItem.selectedImage {
tabBarController.tabBar.items?[index].selectedImage = selectedImage
}
} else {
if tabItem.hasDarkModeSupport && isDarkModeEnable {
if let image = UIImage.init(systemName: "\(tabItem.imageName)-dark") {
tabBarController.tabBar.items?[index].image = image
} else if let image = UIImage.init(systemName: tabItem.imageName) {
tabBarController.tabBar.items?[index].image = image
}
if let selectedImage = UIImage.init(systemName: "\(tabItem.selectedImageName)-dark") {
tabBarController.tabBar.items?[index].selectedImage = selectedImage
} else if let selectedImage = UIImage.init(systemName: tabItem.selectedImageName) {
tabBarController.tabBar.items?[index].selectedImage = selectedImage
}
} else {
if let image = UIImage.init(systemName: tabItem.imageName) {
tabBarController.tabBar.items?[index].image = image
}
if let selectedImage = UIImage.init(systemName: tabItem.selectedImageName) {
tabBarController.tabBar.items?[index].selectedImage = selectedImage
}
}
}
}
}
class Coordinator: NSObject, UITabBarControllerDelegate {
var parent: MyTabView
init(_ tabBarController: MyTabView) {
self.parent = tabBarController
}
func tabBarController(_ tabBarController: UITabBarController, didSelect viewController: UIViewController) {
parent.selectedIndex = tabBarController.selectedIndex
}
}
func view<HostedView:View>(item:MyTabItem, #ViewBuilder sheet: #escaping () -> HostedView) -> MyTabView {
self.viewModel.controllers.append(UIHostingController.init(rootView: sheet()))
self.viewModel.tabItems.append(item)
return self
}
}
Having the same issue myself
"Hackish" workaround is to wrap the NewView.body in a List:
#State var text:String = ""
var title:String
var body: some View {
List {
VStack {
Spacer()
Text("Hello")
TextField(title, text: self.$text)
.textFieldStyle(RoundedBorderTextFieldStyle())
}.padding()
.onAppear {
debugPrint("OnApper \(self.title)")
}
}
}
}
Could also work to use a LazyVStack, but haven't gotten to test it as my project targets 13.x
Same issue here OnAppear calls unexpectedly when Keyboard Appears in SwiftUI
Starting point is a NavigationView within a TabView. I'm struggling with finding a SwiftUI solution to pop to the root view within the navigation stack when the selected tab is tapped again. In the pre-SwiftUI times, this was as simple as the following:
func tabBarController(_ tabBarController: UITabBarController, didSelect viewController: UIViewController) {
let navController = viewController as! UINavigationController
navController.popViewController(animated: true)
}
Do you know how the same thing can be achieved in SwiftUI?
Currently, I use the following workaround that relies on UIKit:
if let windowScene = scene as? UIWindowScene {
let window = UIWindow(windowScene: windowScene)
let navigationController = UINavigationController(rootViewController: UIHostingController(rootView: MyCustomView() // -> this is a normal SwiftUI file
.environment(\.managedObjectContext, context)))
navigationController.tabBarItem = UITabBarItem(title: "My View 1", image: nil, selectedImage: nil)
// add more controllers that are part of tab bar controller
let tabBarController = UITabBarController()
tabBarController.viewControllers = [navigationController /* , additional controllers */ ]
window.rootViewController = tabBarController // UIHostingController(rootView: contentView)
self.window = window
window.makeKeyAndVisible()
}
Here is possible approach. For TabView it gives the same behaviour as tapping to the another tab and back, so gives persistent look & feel.
Tested & works with Xcode 11.2 / iOS 13.2
Full module code:
import SwiftUI
struct TestPopToRootInTab: View {
#State private var selection = 0
#State private var resetNavigationID = UUID()
var body: some View {
let selectable = Binding( // << proxy binding to catch tab tap
get: { self.selection },
set: { self.selection = $0
// set new ID to recreate NavigationView, so put it
// in root state, same as is on change tab and back
self.resetNavigationID = UUID()
})
return TabView(selection: selectable) {
self.tab1()
.tabItem {
Image(systemName: "1.circle")
}.tag(0)
self.tab2()
.tabItem {
Image(systemName: "2.circle")
}.tag(1)
}
}
private func tab1() -> some View {
NavigationView {
NavigationLink(destination: TabChildView()) {
Text("Tab1 - Initial")
}
}.id(self.resetNavigationID) // << making id modifiable
}
private func tab2() -> some View {
Text("Tab2")
}
}
struct TabChildView: View {
var number = 1
var body: some View {
NavigationLink("Child \(number)",
destination: TabChildView(number: number + 1))
}
}
struct TestPopToRootInTab_Previews: PreviewProvider {
static var previews: some View {
TestPopToRootInTab()
}
}
Here's an approach that uses a PassthroughSubject to notify the child view whenever the tab is re-selected, and a view modifier to allow you to attach .onReselect() to a view.
import SwiftUI
import Combine
enum TabSelection: String {
case A, B, C // etc
}
private struct DidReselectTabKey: EnvironmentKey {
static let defaultValue: AnyPublisher<TabSelection, Never> = Just(.Mood).eraseToAnyPublisher()
}
private struct CurrentTabSelection: EnvironmentKey {
static let defaultValue: Binding<TabSelection> = .constant(.Mood)
}
private extension EnvironmentValues {
var tabSelection: Binding<TabSelection> {
get {
return self[CurrentTabSelection.self]
}
set {
self[CurrentTabSelection.self] = newValue
}
}
var didReselectTab: AnyPublisher<TabSelection, Never> {
get {
return self[DidReselectTabKey.self]
}
set {
self[DidReselectTabKey.self] = newValue
}
}
}
private struct ReselectTabViewModifier: ViewModifier {
#Environment(\.didReselectTab) private var didReselectTab
#State var isVisible = false
let action: (() -> Void)?
init(perform action: (() -> Void)? = nil) {
self.action = action
}
func body(content: Content) -> some View {
content
.onAppear {
self.isVisible = true
}.onDisappear {
self.isVisible = false
}.onReceive(didReselectTab) { _ in
if self.isVisible, let action = self.action {
action()
}
}
}
}
extension View {
public func onReselect(perform action: (() -> Void)? = nil) -> some View {
return self.modifier(ReselectTabViewModifier(perform: action))
}
}
struct NavigableTabViewItem<Content: View>: View {
#Environment(\.didReselectTab) var didReselectTab
let tabSelection: TabSelection
let imageName: String
let content: Content
init(tabSelection: TabSelection, imageName: String, #ViewBuilder content: () -> Content) {
self.tabSelection = tabSelection
self.imageName = imageName
self.content = content()
}
var body: some View {
let didReselectThisTab = didReselectTab.filter( { $0 == tabSelection }).eraseToAnyPublisher()
NavigationView {
self.content
.navigationBarTitle(tabSelection.localizedStringKey, displayMode: .inline)
}.tabItem {
Image(systemName: imageName)
Text(tabSelection.localizedStringKey)
}
.tag(tabSelection)
.navigationViewStyle(StackNavigationViewStyle())
.keyboardShortcut(tabSelection.keyboardShortcut)
.environment(\.didReselectTab, didReselectThisTab)
}
}
struct NavigableTabView<Content: View>: View {
#State private var didReselectTab = PassthroughSubject<TabSelection, Never>()
#State private var _selection: TabSelection = .Mood
let content: Content
init(#ViewBuilder content: () -> Content) {
self.content = content()
}
var body: some View {
let selection = Binding(get: { self._selection },
set: {
if self._selection == $0 {
didReselectTab.send($0)
}
self._selection = $0
})
TabView(selection: selection) {
self.content
.environment(\.tabSelection, selection)
.environment(\.didReselectTab, didReselectTab.eraseToAnyPublisher())
}
}
}
Here's how I did it:
struct UIKitTabView: View {
var viewControllers: [UIHostingController<AnyView>]
init(_ tabs: [Tab]) {
self.viewControllers = tabs.map {
let host = UIHostingController(rootView: $0.view)
host.tabBarItem = $0.barItem
return host
}
}
var body: some View {
TabBarController(controllers: viewControllers).edgesIgnoringSafeArea(.all)
}
struct Tab {
var view: AnyView
var barItem: UITabBarItem
init<V: View>(view: V, barItem: UITabBarItem) {
self.view = AnyView(view)
self.barItem = barItem
}
}
}
struct TabBarController: UIViewControllerRepresentable {
var controllers: [UIViewController]
func makeUIViewController(context: Context) -> UITabBarController {
let tabBarController = UITabBarController()
tabBarController.viewControllers = controllers
tabBarController.delegate = context.coordinator
return tabBarController
}
func updateUIViewController(_ uiViewController: UITabBarController, context: Context) { }
}
extension TabBarController {
func makeCoordinator() -> TabBarController.Coordinator {
Coordinator(self)
}
class Coordinator: NSObject, UITabBarControllerDelegate {
var parent: TabBarController
init(_ parent: TabBarController){self.parent = parent}
var previousController: UIViewController?
private var shouldSelectIndex = -1
func tabBarController(_ tabBarController: UITabBarController, shouldSelect viewController: UIViewController) -> Bool {
shouldSelectIndex = tabBarController.selectedIndex
return true
}
func tabBarController(_ tabBarController: UITabBarController, didSelect viewController: UIViewController) {
if shouldSelectIndex == tabBarController.selectedIndex {
if let navVC = tabBarController.viewControllers![shouldSelectIndex].nearestNavigationController {
if (!(navVC.popViewController(animated: true) != nil)) {
navVC.viewControllers.first!.scrollToTop()
}
}
}
}
}
}
extension UIViewController {
var nearestNavigationController: UINavigationController? {
if let selfTypeCast = self as? UINavigationController {
return selfTypeCast
}
if children.isEmpty {
return nil
}
for child in self.children {
return child.nearestNavigationController
}
return nil
}
}
extension UIViewController {
func scrollToTop() {
func scrollToTop(view: UIView?) {
guard let view = view else { return }
switch view {
case let scrollView as UIScrollView:
if scrollView.scrollsToTop == true {
scrollView.setContentOffset(CGPoint(x: 0.0, y: -scrollView.safeAreaInsets.top), animated: true)
return
}
default:
break
}
for subView in view.subviews {
scrollToTop(view: subView)
}
}
scrollToTop(view: view)
}
}
Then in ContentView.swift I use it like this:
struct ContentView: View {
var body: some View {
ZStack{
UIKitTabView([
UIKitTabView.Tab(
view: FirstView().edgesIgnoringSafeArea(.top),
barItem: UITabBarItem(title: "Tab1", image: UIImage(systemName: "star"), selectedImage: UIImage(systemName: "star.fill"))
),
UIKitTabView.Tab(
view: SecondView().edgesIgnoringSafeArea(.top),
barItem: UITabBarItem(title: "Tab2", image: UIImage(systemName: "star"), selectedImage: UIImage(systemName: "star.fill"))
),
])
}
}
}
Note that when the user is already on the root view, it scrolls to top automatically
Here's what I did with introspect swiftUI library.
https://github.com/siteline/SwiftUI-Introspect
struct TabBar: View {
#State var tabSelected: Int = 0
#State var navBarOne: UINavigationController?
#State var navBarTwo: UINavigationController?
#State var navBarThree: UINavigationController?
var body: some View {
return TabView(selection: $tabSelected){
NavView(navigationView: $navBarOne).tabItem {
Label("Home1",systemImage: "bag.fill")
}.tag(0)
NavView(navigationView: $navBarTwo).tabItem {
Label("Orders",systemImage: "scroll.fill" )
}.tag(1)
NavView(navigationView: $navBarThree).tabItem {
Label("Wallet", systemImage: "dollarsign.square.fill" )
// Image(systemName: tabSelected == 2 ? "dollarsign.square.fill" : "dollarsign.square")
}.tag(2)
}.onTapGesture(count: 2) {
switch tabSelected{
case 0:
self.navBarOne?.popToRootViewController(animated: true)
case 1:
self.navBarTwo?.popToRootViewController(animated: true)
case 2:
self.navBarThree?.popToRootViewController(animated: true)
default:
print("tapped")
}
}
}
}
NavView:
import SwiftUI
import Introspect
struct NavView: View {
#Binding var navigationView: UINavigationController?
var body: some View {
NavigationView{
VStack{
NavigationLink(destination: Text("Detail view")) {
Text("Go To detail")
}
}.introspectNavigationController { navController in
navigationView = navController
}
}
}
}
This actually isn't the best approach because it makes the entire tab view and everything inside of it have the double-tap gesture which would pop the view to its root. My current fix for this allows for one tap to pop up root view haven't figured out how to add double tap
struct TabBar: View {
#State var tabSelected: Int = 0
#State var navBarOne: UINavigationController?
#State var navBarTwo: UINavigationController?
#State var navBarThree: UINavigationController?
#State var selectedIndex:Int = 0
var selectionBinding: Binding<Int> { Binding(
get: {
self.selectedIndex
},
set: {
if $0 == self.selectedIndex {
popToRootView(tabSelected: $0)
}
self.selectedIndex = $0
}
)}
var body: some View {
return TabView(selection: $tabSelected){
NavView(navigationView: $navBarOne).tabItem {
Label("Home1",systemImage: "bag.fill")
}.tag(0)
NavView(navigationView: $navBarTwo).tabItem {
Label("Orders",systemImage: "scroll.fill" )
}.tag(1)
NavView(navigationView: $navBarThree).tabItem {
Label("Wallet", systemImage: "dollarsign.square.fill" )
// Image(systemName: tabSelected == 2 ? "dollarsign.square.fill" : "dollarsign.square")
}.tag(2)
}
}
func popToRootView(tabSelected: Int){
switch tabSelected{
case 0:
self.navBarOne?.popToRootViewController(animated: true)
case 1:
self.navBarTwo?.popToRootViewController(animated: true)
case 2:
self.navBarThree?.popToRootViewController(animated: true)
default:
print("tapped")
}
}
}
I took an approach similar to Asperi
Use a combination of a custom binding, and a separately stored app state var for keeping state of the navigation link.
The custom binding allows you to see all taps basically even when the current tab is the one thats tapped, something that onChange of tab selection binding doesn't show. This is what imitates the UIKit TabViewDelegate behavior.
This doesn't require a "double tap", if you just a single tap of the current, if you want double tap you'll need to implement your own tap/time tracking but shouldn't be too hard.
class AppState: ObservableObject {
#Published var mainViewShowingDetailView = false
}
struct ContentView: View {
#State var tabState: Int = 0
#StateObject var appState = AppState()
var body: some View {
let binding = Binding<Int>(get: { tabState },
set: { newValue in
if newValue == tabState { // tapped same tab they're already on
switch newValue {
case 0: appState.mainViewShowingDetailView = false
default: break
}
}
tabState = newValue // make sure you actually set the storage
})
TabView(selection: binding) {
MainView()
.tabItem({ Label("Home", systemImage: "list.dash") })
.tag(0)
.environmentObject(appState)
}
}
}
struct MainView: View {
#EnvironmentObject var appState: AppState
var body: {
NavigationView {
VStack {
Text("Hello World")
NavigationLink(destination: DetailView(),
isActive: $appState.mainViewShowingDetailView,
label: { Text("Show Detail") })
}
}
}
}
struct DetailView: View {
...
}
iOS 16 / NavigationStack approach with PassthroughSubject
Uses willSet on selectedTab to get the tap event, and uses a PassthroughSubject for sending the event to the children. This is picked up by the .onReceived and calls a function for popping the views from the NavigationStack
Did a full write up here: https://kentrobin.com/home/tap-tab-to-go-back/ and created a working demo project here: https://github.com/kentrh/demo-tap-tab-to-go-back
class HomeViewModel: ObservableObject {
#Published var selectedTab: Tab = .tab1 {
willSet {
if selectedTab == newValue {
subject.send(newValue)
}
}
}
let subject = PassthroughSubject<Tab, Never>()
enum Tab: Int {
case tab1 = 0
}
}
struct HomeView: View {
#StateObject var viewModel: HomeViewModel = .init()
var body: some View {
TabView(selection: $viewModel.selectedTab) {
Tab1View(subject: viewModel.subject)
.tag(HomeViewModel.Tab.tab1)
.tabItem {
Label("Tab 1", systemImage: "1.lane")
Text("Tab 1", comment: "Tab bar title")
}
}
}
}
struct Tab1View: View {
#StateObject var viewModel: Tab1ViewModel = .init()
let subject: PassthroughSubject<HomeViewModel.Tab, Never>
var body: some View {
NavigationStack(path: $viewModel.path) {
List {
NavigationLink(value: Tab1ViewModel.Route.viewOne("From tab 1")) {
Text("Go deeper to OneView")
}
NavigationLink(value: Tab1ViewModel.Route.viewTwo("From tab 1")) {
Text("Go deeper to TwoView")
}
}
.navigationTitle("Tab 1")
.navigationDestination(for: Tab1ViewModel.Route.self, destination: { route in
switch route {
case let .viewOne(text):
Text(text)
case let .viewTwo(text):
Text(text)
}
})
.onReceive(subject) { tab in
if case .tab1 = tab { viewModel.tabBarTapped() }
}
}
}
}
class Tab1ViewModel: ObservableObject {
#Published var path: [Route] = []
func tabBarTapped() {
if path.count > 0 {
path.removeAll()
}
}
enum Route: Hashable {
case viewOne(String)
case viewTwo(String)
}
}
I understand there is PresentationButton and NavigationButton in order to change views in the latest SwiftUI. However I want to do a simple operation like below. When user clicks on SignIn button if credentials are correct it will sign them in but also do a segue (in this case change the view). However I could not check if they are correct in PresentationButton and I could not change the view in a normal button.
Is there another way to do that?
#IBAction func signInClicked(_ sender: Any) {
if emailText.text != "" && passwordText.text != "" {
Auth.auth().signIn(withEmail: emailText.text!, password: passwordText.text!) { (userdata, error) in
if error != nil {
//error
} else {
performSegue(withIdentifier: "toFeedActivity", sender: nil)
}
}
} else {
//error
}
}
Here's one way.
struct AppContentView: View {
#State var signInSuccess = false
var body: some View {
return Group {
if signInSuccess {
AppHome()
}
else {
LoginFormView(signInSuccess: $signInSuccess)
}
}
}
}
struct LoginFormView : View {
#State private var userName: String = ""
#State private var password: String = ""
#State private var showError = false
#Binding var signInSuccess: Bool
var body: some View {
VStack {
HStack {
Text("User name")
TextField("type here", text: $userName)
}.padding()
HStack {
Text(" Password")
TextField("type here", text: $password)
.textContentType(.password)
}.padding()
Button(action: {
// Your auth logic
if(self.userName == self.password) {
self.signInSuccess = true
}
else {
self.showError = true
}
}) {
Text("Sign in")
}
if showError {
Text("Incorrect username/password").foregroundColor(Color.red)
}
}
}
}
struct AppHome: View {
var body: some View {
VStack {
Text("Hello freaky world!")
Text("You are signed in.")
}
}
}
I had the same need in one of my app and I've found a solution...
Basically you need to insert your main view in a NavigationView, then add an invisible NavigationLink in you view, create a #state var that controls when you want to push the view and change it's value on your login callback...
That's the code:
struct ContentView: View {
#State var showView = false
var body: some View {
NavigationView {
VStack {
Button(action: {
print("*** Login in progress... ***")
DispatchQueue.main.asyncAfter(deadline: .now() + 3) {
self.showView = true
}
}) {
Text("Push me and go on")
}
//MARK: - NAVIGATION LINKS
NavigationLink(destination: PushedView(), isActive: $showView) {
EmptyView()
}
}
}
}
}
struct PushedView: View {
var body: some View {
Text("This is your pushed view...")
.font(.largeTitle)
.fontWeight(.heavy)
}
}
Try with state & .sheet
struct ContentView: View {
#State var showingDetail = false
var body: some View {
Button(action: {
self.showingDetail.toggle()
}) {
Text("Show Detail")
}.sheet(isPresented: $showingDetail) {
DetailView()
}
}
}
You can use navigation link with tags so,
Here is the code:
first of all, declare tag var
#State var tag : Int? = nil
then create your button view:
Button("Log In", action: {
Auth.auth().signIn(withEmail: self.email, password: self.password, completion: { (user, error) in
if error == nil {
self.tag = 1
print("success")
}else{
print(error!.localizedDescription)
}
})
So when log in success tag will become 1 and when tag will become 1 your navigation link will get executed
Navigation Link code:
NavigationLink(destination: HomeView(), tag: 1, selection: $tag) {
EmptyView()
}.disabled(true)
if you are using Form use .disabled because here the empty view will be visible on form and you don't want your user to click on it and go to the homeView.