Btukfyl

hi I want to make a local notification from string time, I want the notification launch 10 minute before given time. I have trouble how to make the time from 4:01 into 3:51, please help. this is my code

let a = "4:01"



func startNoftification(prayer: String) {

    let time = prayer.split(separator: ":").map { (x) -> Int in

    return Int(String(x))!

}

   let content = UNMutableNotificationContent()

   content.title = "Adzan"

   content.body = "it's time to sholat dzuhur"



   let gregorian = Calendar(identifier: .gregorian)

   var component = gregorian.dateComponents([.year, .month, .day, .hour, .minute, .second], from: Date())

   component.hour = time[0]

   component.minute = time[1] - 10



   guard let date = gregorian.date(from: component) else { return }

   let triggerDaily = Calendar.current.dateComponents([.hour, .minute, .second], from: date)

   let trigger = UNCalendarNotificationTrigger(dateMatching: triggerDaily, repeats: true)

   let request = UNNotificationRequest(identifier: "Hijrah", content: content, trigger: trigger)



   UNUserNotificationCenter.current().add(request) { (error) in

    if let err = error {

        print("Notif error:", err)

        return

    }

  }

}

Is this what you need?

let time = "4:01"



let dateFormatter = DateFormatter()

dateFormatter.dateFormat = "hh:mm"



guard let date = dateFormatter.date(from: time) else {

    return 

} 



let targetTime = Date(timeInterval: -(10 * 60), since: date) // Change time interval to required value in seconds

let targetTimeString = dateFormatter.string(from: targetTime)

print(targetTimeString) // Prints 3:51

Or if your countdown time has a lot of time components, use DateComponents.

var dateComponents = DateComponents()

dateComponents.minute = -10

// Other components



if let targetTime = Calendar.current.date(byAdding: dateComponents, to: date)

    print(dateFormatter.string(from: targetTime))

}

Here I have solution combine with rakesha Shastri answer, hopefully it can helps others.

First import UserNotification in appDelegate and in your controller

import UserNotification

and add code for didFinishWithLaunchingWithOptions

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



    UNUserNotificationCenter.current().requestAuthorization(options: [.alert, .badge]) { (granted, error) in

        if let err = error {

            print("Notifications permission denied because:", err)

            return

        }



        if granted {

            print("Notifications permission granted.")

        }

    }

}

and you can make a function and add string time parameters either from API or arbitrary string, since I'm not using function so I pass my solution in viewDidLoad

let adzan = "4:01"



let content = UNMutableNotificationContent()

    content.title = "Adzan"

    content.body = "It's time for sholat"

    content.sound = UNNotificationSound.default



    // Format the date first from string time

    let dateFormatter = DateFormatter()

    dateFormatter.dateFormat = "HH:mm"



    //addingTimeInterval is where you want to set notification before or after deciding time in this case I set it 10 minute before deciding time

    guard let date = dateFormatter.date(from: adzan)?.addingTimeInterval(-600) else { return }



    // and convert our date into dateComponents

    let triggerDate = Calendar.current.dateComponents([.hour, .minute, .second], from: date)



    let trigger = UNCalendarNotificationTrigger(dateMatching: triggerDate, repeats: true)



    let request = UNNotificationRequest(identifier: UUID().uuidString, content: content, trigger: trigger)



    UNUserNotificationCenter.current().add(request)