How to send Local notifications when app is closed (swift)?

Question

I have a database where products with expiration dates are stored. When the expiry date expires, the user should receive a notification about this. But these notifications should also come if the user turned off their application (kill app). Question: how to do this? Show me the code, please. My code is (AppDelegate):

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {

    let center = UNUserNotificationCenter.current()
    center.requestAuthorization(options: [.alert, .sound]) { (granted, error) in }

    return true
}

and (ViewController):

    let center = UNUserNotificationCenter.current()

    let content = UNMutableNotificationContent()
    content.title = "title"
    content.body = "\(overdueProductsStringArray)"
    content.sound = UNNotificationSound.default()

    let trigger = UNTimeIntervalNotificationTrigger(timeInterval: 5, repeats: false)
    let request = UNNotificationRequest(identifier: "t", content: content, trigger: trigger)

    center.add(request, withCompletionHandler: nil)

Answer 1

If you go to AppDelegate there is a method called applicationWillTerminate so you just need to call your method that send locations.

func applicationWillTerminate(_ application: UIApplication) {
    // Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.

    let viewControllerWithYourFunction = ViewControllerWithYourFunction()
    viewControllerWithYourFunction.sendLocation()
}