SwiftUI - present sheet programatically - modal-dialog

Question

I would like to have a modal sheet appear with several options for the user to choose from. (The share sheet is a perfect example.) When the user makes a selection, the option sheet disappears and a second sheet appears with the selected option. In the share sheet example, if the user selects print, the share sheet slides down and the print sheet pops up.
I can get the option sheet to appear easily enough. But I haven't figured out how to get the second sheet to appear. I tried attaching the sheet to an empty view and then used UserDefaults to set the bool that activates the second sheet. Nothing.
First Sheet
Button(action: {
UserDefaults.standard.set(true, forKey: showSelectedOption)
showOptionForm = true
}) {
Image(systemName: "square.and.arrow.up")
}
.sheet(isPresented: $showOptionForm) {
OptionView().environment(\.managedObjectContext, self.moc)
})
SecondSheet
EmptyView()
.sheet(isPresented: $showSelectedOption) {
SelectedOptionView().environment(\.managedObjectContext, self.moc)
}
I tried setting the bool shown below in .onAppear, but it does not get called when a modal sheet is dismissed. Is there a way to tell when a view is no longer being covered by a sheet? In UIKit it would have been presentationControllerDidDismiss(_:). Of course, this is assuming that my idea to attach the second sheet to an empty view is even workable.
let showSelectedOption = UserDefaults.standard.bool(forKey: "showSelectedOption")

Answer 1

Here is demo of possible approach - you activate second sheet in onDismiss of first one. Tested with Xcode 12 / iOS 14.
struct DemoTwoSheets: View {
#State private var firstSheet = false
#State private var secondSheet = false
var body: some View {
VStack {
Button("Tap") { self.firstSheet = true }
.sheet(isPresented: $firstSheet, onDismiss: {
self.secondSheet = true
}) {
Text("First sheet")
}
EmptyView()
.sheet(isPresented: $secondSheet) {
Text("Second sheet")
}
}
}
}
Update:
Here is an alternate which works for SwiftUI 1.0 as well. Tested with Xcode 11.4 / iOS 13.4 and Xcode 12b5 / iOS 14.
struct DemoTwoSheets: View {
#State private var firstSheet = false
#State private var secondSheet = false
var body: some View {
VStack {
Button("Tap") { self.firstSheet = true }
.sheet(isPresented: $firstSheet, onDismiss: {
self.secondSheet = true
}) {
Text("First sheet")
}
.background(Color.clear
.sheet(isPresented: $secondSheet) {
Text("Second sheet")
})
}
}
}