presentationPreventsAppTermination(_:)

Declaration

nonisolated func presentationPreventsAppTermination(_ prevents: Bool?) -> some View

Discussion

SwiftUI uses the buttons in a sheet’s toolbar to determine whether a particular sheet should block termination by default. If there is a singular toolbar item with the confirmationAction or the cancellationAction placement and no other toolbar items, the sheet will not prevent termination by default.

Use this modifier to specify whether a sheet should prevent app termination. Pass nil to explicitly request the automatic behavior/for the inert version of this modifier. Non-nil values will override nil, and true takes precedence over false.

Use this modifier within the content argument to View/sheet

struct LaunchScreen: View {
  @State private var presentLogin = false
  var body: some View {
    HomeView()
      .sheet(isPresented: $presentLogin) {
        LoginView()
          // explicitly allow app termination because the
          // default behavior would resolve to `true`.
          .presentationPreventsAppTermination(false)
          .toolbar {
            ToolbarItem(placement: .cancellationAction) {
              Button("Cancel") { presentLogin = false }
            }
            ToolbarItem(placement: .confirmationAction) {
              Button("Login") {
                // Attempt login...
                presentLogin = false
              }
            }
          }
        }
    }
}