This is an enhanced version of Apple's `interactiveDismissDisabled` view modifier which allows you to act on the user's attempt to dismiss a sheet. See my article for more details. I filed a feedback for a feature request to add this to SwiftUI: FB9782213 (https://openradar.appspot.com/FB9782213)

View+InteractiveDismissDisable.swift

import SwiftUI

extension View {
  public func interactiveDismissDisabled(_ isDisabled: Bool = true, onAttemptToDismiss: (() -> Void)? = nil) -> some View {
    InteractiveDismissableView(view: self, isDisabled: isDisabled, onAttemptToDismiss: onAttemptToDismiss)
  }
  
  public func interactiveDismissDisabled(_ isDisabled: Bool = true, attemptToDismiss: Binding<Bool>) -> some View {
    InteractiveDismissableView(view: self, isDisabled: isDisabled) {
      attemptToDismiss.wrappedValue.toggle()
    }
  }
  
}

private struct InteractiveDismissableView<T: View>: UIViewControllerRepresentable {
  let view: T
  let isDisabled: Bool
  let onAttemptToDismiss: (() -> Void)?
  
  func makeUIViewController(context: Context) -> UIHostingController<T> {
    UIHostingController(rootView: view)
  }
  
  func updateUIViewController(_ uiViewController: UIHostingController<T>, context: Context) {
    context.coordinator.dismissableView = self
    uiViewController.rootView = view
    uiViewController.parent?.presentationController?.delegate = context.coordinator
  }
  
  func makeCoordinator() -> Coordinator {
    Coordinator(self)
  }
  
  class Coordinator: NSObject, UIAdaptivePresentationControllerDelegate {
    var dismissableView: InteractiveDismissableView
    
    init(_ dismissableView: InteractiveDismissableView) {
      self.dismissableView = dismissableView
    }
    
    func presentationControllerShouldDismiss(_ presentationController: UIPresentationController) -> Bool {
      !dismissableView.isDisabled
    }
    
    func presentationControllerDidAttemptToDismiss(_ presentationController: UIPresentationController) {
      dismissableView.onAttemptToDismiss?()
    }
  }
}

struct ContentView: View {
  @State var showingSheet = false
  @State var name: String = "Johnny Appleseed"
  var body: some View {
    Form {
      Section("User Profile") {
        Text(name)
      }
      Button("Edit", action: { showingSheet.toggle() })
    }
    .sheet(isPresented: $showingSheet) {
      EditView(name: $name)
    }
  }
}

private class ViewModel: ObservableObject {
  @Published var name: String
  private var original: String
  
  var isModified: Bool {
    print("\(name) - \(original)")
    return name != original
  }
  
  init(name: String) {
    self.name = name
    self.original = name
  }
}

private struct EditView: View {
  @Environment(\.dismiss)  var dismiss
  @Binding var name: String
  
  @StateObject private var viewModel: ViewModel
  @State var showingConfirmationDialog = false
  
  init(name: Binding<String>) {
    self._name = name
    self._viewModel = StateObject(wrappedValue: ViewModel(name: name.wrappedValue))
  }
  
  var body: some View {
    NavigationView {
      Form {
        TextField("Enter your name", text: $viewModel.name)
      }
      .navigationTitle("Edit")
      .navigationBarTitleDisplayMode(.inline)
    }
    .interactiveDismissDisabled(viewModel.isModified) {
      showingConfirmationDialog.toggle()
    }
    .confirmationDialog("", isPresented: $showingConfirmationDialog) {
      Button("Save") {
        name = viewModel.name
        dismiss()
      }
      Button("Discard", role: .destructive) {
        dismiss()
      }
      Button("Cancel", role: .cancel) { }
    }
  }
}

struct ContentView_Previews: PreviewProvider {
  static var previews: some View {
    ContentView()
  }
}

Did anything in iOS 16 get announced which would implement this functionality natively in SwiftUI?

Did anything in iOS 16 get announced which would implement this functionality natively in SwiftUI?

nope, hoping for WWDC 23 :)

@peterfriese hey there. So I was trying out your solution, andI am looking for the exact behavior this code providers, but i noticed something.
The interactiveDismissDisabled doesn't work unless you edit something in the view. Meaning that, if you had a view, and had any editable view in it, (TextField, etc), and you add your interactiveDismissDisabled to it, and set it to always true, always disable dismissing, it won't work unless the user edits something in the view.

i noticed this, uiViewController.parent?.presentationController?.delegate = context.coordinator will not be set the first time because uiViewController.parent?.presentationController will be nil the first time, but after you edit something in the screen, it will call updateUIViewController again which will set the delegate because it won't be nil. See the pic down.

so if say we had a view with only a button in it, or text, and add interactiveDismissDisabled with always true, it won't work, because we don't edit anything in the screen, which means that the delegate will only be set the first time when it's nil.

i am not sure why this is happening, but if we can fix it so that we can have more control over this, and possibly have the option to always disable the dismissal, even if we don't edit anything, and even for views that don 't have anything editable in the screen.

thanks!

Hey man, how do i get rid of the white spaces in the safe areas?

@peterfriese hey there. So I was trying out your solution, andI am looking for the exact behavior this code providers, but i noticed something. The interactiveDismissDisabled doesn't work unless you edit something in the view. Meaning that, if you had a view, and had any editable view in it, (TextField, etc), and you add your interactiveDismissDisabled to it, and set it to always true, always disable dismissing, it won't work unless the user edits something in the view.

i noticed this, uiViewController.parent?.presentationController?.delegate = context.coordinator will not be set the first time because uiViewController.parent?.presentationController will be nil the first time, but after you edit something in the screen, it will call updateUIViewController again which will set the delegate because it won't be nil. See the pic down.

so if say we had a view with only a button in it, or text, and add interactiveDismissDisabled with always true, it won't work, because we don't edit anything in the screen, which means that the delegate will only be set the first time when it's nil.

i am not sure why this is happening, but if we can fix it so that we can have more control over this, and possibly have the option to always disable the dismissal, even if we don't edit anything, and even for views that don 't have anything editable in the screen.

thanks!

Making isDisabled a binding should fix it as a binding adds this view to the view update notification chain.