Random Element that is not repeating in every TimeIntervalNotification

Question

I want to send the user TimeInterval Notifications, but it should send in every Notification an other element from my array (other message) But only in the first message its a randomElement and then in the others there are all the same as the first. But I want every time an other message in the Notification.

class ViewController: UIViewController {

    let unCenter = UNUserNotificationCenter.current()

    var myFirstArray = ["1", "2", "3", "4", "5", "6", "7", "8", "9"]

    override func viewDidLoad() {
        super.viewDidLoad()

        unCenter.requestAuthorization(options: [.alert, .sound, .badge]) { (didAllow, error) in
            print(error ?? "No error")
        }

        unCenter.delegate = self
    }




    @IBAction func button_Tapped(_ sender: UIButton) {

        if let random = myFirstArray.randomElement(){
            sendNotification(body: random, time: 70)
        }
    }



    func sendNotification(body: String, time: TimeInterval){

        let content = UNMutableNotificationContent()
        content.body = body
        content.sound = .default

        let trigger = UNTimeIntervalNotificationTrigger(timeInterval: time, repeats: true)

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

        unCenter.add(request, withCompletionHandler: nil)
    }




}


extension ViewController: UNUserNotificationCenterDelegate{

    func userNotificationCenter(_ center: UNUserNotificationCenter, willPresent notification: UNNotification, withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void) {

        print("will present")
    }

    func userNotificationCenter(_ center: UNUserNotificationCenter, didReceive response: UNNotificationResponse, withCompletionHandler completionHandler: @escaping () -> Void) {

        print("did receive")
    }
}

Answer 1

If you need a random element each time you must register for different notifications at a time interval that keeps on increasing as you register each notification. Also, make sure you're setting the repeats parameter set as false. Here, you're just making a single notification and set it as repeating which means you get the same notification at the specified time interval. Here's a code snippet of how you can achieve this.

var time: Double = 0

@IBAction func button_Tapped(_ sender: UIButton) {
    for _ in 0..<myFirstArray.count {
        if let random = myFirstArray.randomElement() {
            time += 70
            sendNotification(body: random)
        }
    }
}

func sendNotification(body: String){

    let content = UNMutableNotificationContent()
    content.body = body
    content.sound = .default

    let trigger = UNTimeIntervalNotificationTrigger(timeInterval: time, repeats: true)
    let request = UNNotificationRequest(identifier: "request", content: content, trigger: trigger)
    unCenter.add(request, withCompletionHandler: nil)
}

Answer 2

Code looks now so: But I dont get Notifcations.

class ViewController: UIViewController {

var time: Double = 0

let unCenter = UNUserNotificationCenter.current()

var myFirstArray = ["1", "2", "3", "4", "5", "6", "7", "8", "9"]

override func viewDidLoad() {
    super.viewDidLoad()

    unCenter.requestAuthorization(options: [.alert, .sound, .badge]) { (didAllow, error) in
        print(error ?? "No error")
    }

    unCenter.delegate = self
}


@IBAction func button_Tapped(_ sender: UIButton) {

    for _ in 0..<myFirstArray.count {
        if let random = myFirstArray.randomElement() {
            time += 70
            sendNotification(body: random)
        }
    }
}


func sendNotification(body: String){

    let content = UNMutableNotificationContent()
        content.body = body
        content.sound = .default

        let trigger = UNTimeIntervalNotificationTrigger(timeInterval: time, repeats: false)
        let request = UNNotificationRequest(identifier: "request", content: content, trigger: trigger)
        unCenter.add(request, withCompletionHandler: nil)
    }
}

extension ViewController: UNUserNotificationCenterDelegate{

func userNotificationCenter(_ center: UNUserNotificationCenter, willPresent notification: UNNotification, withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void) {

    print("will present")
}

func userNotificationCenter(_ center: UNUserNotificationCenter, didReceive response: UNNotificationResponse, withCompletionHandler completionHandler: @escaping () -> Void) {

    print("did receive")
}

}