How to show a Dialog before closing an app in SwiftUI?

[torstenbernhard]

When a user closes the last window, the app shall quit.
This works well with appDelegate:

import SwiftUI

class AppDelegate: NSObject, NSApplicationDelegate {
    
    func applicationShouldTerminateAfterLastWindowClosed(_ sender: NSApplication) -> Bool {
        return true
    }
}
    
@main
struct buttonsApp: App {
    @NSApplicationDelegateAdaptor(AppDelegate.self) var appDelegate
    
    var body: some Scene {  // opens a window
        WindowGroup {
            ContentView()
        }
        .windowResizability(.contentSize)
    }
}

What is the proper way in SwiftUI of showing an alert that the app will quit and give the user the option to proceed or to cancel quit?

[GreatOm]

Hi!

AFAIK there is no SwiftUI-way for this. I use the old way in my app, too

final class MyWindowDelegate: NSObject, NSWindowDelegate {
    func windowShouldClose(_ sender: NSWindow) -> Bool {
        // some code
        return true
    }
}

final class AppDelegate: NSObject, NSApplicationDelegate, ObservableObject {
    func applicationShouldTerminate(_ sender: NSApplication) -> NSApplication.TerminateReply {
        // some code
        return .terminateNow
    }
}