I have a master detail arrangement of 2 views, a list on one from which the user selects a record in Core Data which links to a detail view (NavigationLink) where the user edits the corresponding record. On the edit view there is a Save button, but the big default dismiss button provided to the NavigationLink lets the user dismiss the view without saving, which is likely to happen.
Is there some modifier / event handler that will let me throw up an alert if the user has unsaved edits?
Without any code I can't know for sure if this will work but I just tried this in my MacOS app, which has a detail view appear in a sheet modal, and it works. In my detail view I also have a button that calls a save function. To dismiss my detail view I have the following button:
Button(action: {
dismiss()
}, label: {
Text("Back")
})
All I needed to do is add a call to my save function above "dismiss()"
Button(action: {
FileManager().saveText(infoText!)
dismiss()
}, label: {
Text("Back")
})
Now when I hit the button to dismiss my detail view my save function runs, which shows a save dialog, and when I hit the "Save" button in the dialog it saves the file and then the detail view closes. I hope this helps!
But there you are adding a new Back button. I see that as a Cancel button. I wanted to insert an alert to say "Changes will be lost if you quit without saving Quit | Stay", or something like that.
I am thinking I will avoid using the default NavigationLink behaviour and add my own buttons, as you are suggesting.
You can use onDisappear in destinationView:
struct DestinationView: View {
var body: some View {
VStack {
Text("Destination")
// other stuff
}
.onDisappear {
print("ContentView disappeared!")
}
}
}
