SwiftUI - Dismissing a view, app goes back to content view instead of last view - ios

Question

I have 3 views within my app where clicking on a button on each view opens a new view. When button is clicked on 3rd view, I wish to dismiss 3rd view and 2nd view should appear. However I am noticing that app navigates back to first view instead of 2nd view.
Note: I have lots of elements, hence lots of code in my app. I removed all of them and adding minimal working code here with which I am still able to repro the problem.
// *** Main App***
#main
struct sample_sampleApp: App {
var body: some SwiftUI.Scene {
WindowGroup {
NavigationView {
ContentView().ignoresSafeArea()
}.navigationViewStyle(.stack)
}
}
}
// *** Content View or First View***
import SwiftUI
struct ContentView: View {
#State private var goToView2 = false
var body: some View {
VStack {
NavigationLink(destination: View2(), isActive: $goToView2) {
Button(action: { goToView2.toggle() }) {
Text("This is first view - Click to go to View 2").foregroundColor(.red).font(.title)
}
}
}
}
}
// *** View2 View***
import SwiftUI
import Combine
struct View2: View {
#ObservedObject var viewModel: View2ViewModel = View2ViewModel()
var body: some View {
VStack {
switch viewModel.state {
case .showView2:
VStack(alignment: .leading, spacing: 8) {
Button(action: { viewModel.navigateToView3() } ) {
Text("Second View - Click to go to View 3").foregroundColor(.blue).font(.title)
}
}
case .showView3:
View3()
}
}
.onAppear() {
viewModel.isViewVisible = true
viewModel.doSomething()
}
.onDisappear() {
viewModel.isViewVisible = false
}
}
}
// *** View model for view 2***
class View2ViewModel: ObservableObject {
enum View2AppState {
case showView2
case showView3
}
// UI changes when state gets updated.
#Published var state: View2AppState = .showView2
var isViewVisible = false
func doSomething() {
self.state = .showView2
}
func navigateToView3() {
self.state = .showView3
}
}
// *** View3***
struct View3: View {
#ObservedObject var viewModel: View3ViewModel = View3ViewModel()
#Environment(\.dismiss) var dismiss
var body: some View {
VStack {
switch viewModel.state {
case .showView3:
VStack(alignment: .leading, spacing: 8) {
Button(action: { dismiss() } ) {
Text("Third View - Click to dismiss this and to go back to view 2").foregroundColor(.green).font(.title)
}
}
}
}
.onAppear() {
viewModel.isViewVisible = true
viewModel.doSomething()
}
.onDisappear() {
viewModel.isViewVisible = false
}.navigationBarBackButtonHidden(true)
}
}
// *** View model for view 3***
class View3ViewModel: ObservableObject {
enum View3AppState {
case showView3
}
// UI changes when state gets updated.
#Published var state: View3AppState = .showView3
var isViewVisible = false
func doSomething() {
self.state = .showView3
}
}
Not sure what am I doing wrong. Sometime back I did use dismiss() while dismissing sheet and it worked fine, but not this this case. I am running this code on iOS 16.0, however my test app is set to iOS 15 as minimum version.
Edit: I tested on iOS 15.0 as well and was able to repro on it too, so something must be wrong with my code then. Not able to figure out what. I am using NavigationView in and navigation view style as Stack.

Answer 1

When button is clicked on 3rd view, I wish to dismiss 3rd view and 2nd view should appear.
Let's first have a look at the code of view2.
struct View2: View {
#ObservedObject var viewModel: View2ViewModel = View2ViewModel()
var body: some View {
VStack {
switch viewModel.state {
case .showView2:
VStack(alignment: .leading, spacing: 8) {
Button(action: { viewModel.navigateToView3() } ) {
Text("Second View - Click to go to View 3").foregroundColor(.blue).font(.title)
}
}
case .showView3:
View3()
}
}
}
}
// here viewModel.navigateToView3() is just changing this state
// func navigateToView3() {
// self.state = .showView3
// }
The current code behavior, when tapping to navigate to view3, replaces the content of view2 with view3 instead of actually navigating to it.
Therefore, when the dismiss function is called, it should not return to view2 as it is already in view2 displaying the content of view3.
So, going back to view1 on the dismiss press is actually the correct behavior as per the code.
If you desire the outcome you are asking, consider modifying the code using a closure passed into the child view to change the state in view2 or explore this answer to actually navigate to it.