Schedule start of notification requests

Question

Created Feb ’21

Replies 12

Boosts 0

Views 3.0k

Participants 4

Hello all,

I have an app that allows users to create a repeating event. Based on user-provided start date and repeat pattern (daily, weekly, monthly, etc.), the app schedules a repeating notification using UNUserNotificationCenter with a UNCalendarNotificationTrigger.

If the repeat pattern is daily, the user receives notifications each day at the specified time. This works perfectly.

But because UNCalendarNotificationTrigger uses a start date and matches components (in the case of daily repetition, it matches the timezone, hour, minute, and second), if the user enters a start date that is in the future, UNCalenderNotificationTrigger fires before the selected start date because all it does is match components.

Does anyone have ideas for a solution to how I could fix this issue? I was thinking maybe scheduling the scheduling of the notification for a day in advance of the event. I don't want to use a for loop to create multiple notifications because that it difficult to manage.

Boost

Answer 1

OOPer OP

Feb ’21

You may register a notification with specifying the start date, no repeating. You can re-register the everyday notification when processing the date specified notification.

Or you can register a next notification at each time you received a date specific notification.

0

Answer 2

Hu is I OP

Feb ’21

I think your second idea is what I might use, because of this: each event a user creates has a UUID stored in Core Data. The notification identifier is the same as the UUID, so when a user deletes an event, it's really simple to delete the pending notification request. Using your method of creating a new notification when the current one fires, can I recycle the same UUID and keep using that UUID for the future notifications?

Also, I'm not familiar with how to schedule a new notification when the existing one fires. What function is that?

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Answer 3

OOPer OP

Feb ’21

Also, I'm not familiar with how to schedule a new notification when the existing one fires. What function is that?

Please show your code currently registering notification and handling notification. You once wrote This works perfectly.

0

Answer 4

Hu is I OP

Feb ’21

Code Block     func sendNotification(title: String, subtitle: String?, body: String, time: Date, id: UUID, repeatPattern: String) {
        let content = UNMutableNotificationContent()
        content.title = title
        if let subtitle = subtitle {
            content.subtitle = subtitle
        }
        content.body = body
        content.sound = UNNotificationSound.default
        
        let triggerDate = time - 5 * 60
        if repeatPattern == "Daily" {
            let trigger = UNCalendarNotificationTrigger(dateMatching: Calendar.current.dateComponents([.second], from: triggerDate), repeats: true)
            let request = UNNotificationRequest(identifier: "\(id)", content: content, trigger: trigger)
            UNUserNotificationCenter.current().add(request, withCompletionHandler: nil)
        } else if repeatPattern == "Weekly" {
            let trigger = UNCalendarNotificationTrigger(dateMatching: Calendar.current.dateComponents([.timeZone, .weekday, .hour, .minute, .second], from: triggerDate), repeats: true)
            let request = UNNotificationRequest(identifier: "\(id)", content: content, trigger: trigger)
            UNUserNotificationCenter.current().add(request, withCompletionHandler: nil)
        } else if repeatPattern == "Monthly" {
            let trigger = UNCalendarNotificationTrigger(dateMatching: Calendar.current.dateComponents([.timeZone, .weekOfMonth, .weekday, .hour, .minute, .second], from: triggerDate), repeats: true)
            let request = UNNotificationRequest(identifier: "\(id)", content: content, trigger: trigger)
            UNUserNotificationCenter.current().add(request, withCompletionHandler: nil)
        } else if repeatPattern == "None" {
            let trigger = UNCalendarNotificationTrigger(
                dateMatching: Calendar.current.dateComponents([.timeZone, .year, .month, .day, .hour, .minute], from: triggerDate), repeats: true)
            let request = UNNotificationRequest(identifier: "\(id)", content: content, trigger: trigger)
                    UNUserNotificationCenter.current().add(request, withCompletionHandler: nil)
        }
}

Calling the function in the add meeting modal :

Code Block self.notificationManager.sendNotification(title: "Upcoming Meeting", subtitle: nil, body: "\(meetingName) will start in 5 minutes. Tap for meeting information.", time: newMeeting.time!, id: newMeeting.id!, repeatPattern: "\(repeats)")
print("Scheduled repeating notification.")

1

Answer 5

OOPer OP

Feb ’21

Please show your code currently registering notification and handling notification.

Waiting for the code handling notification.

0

Answer 6

Hu is I OP

Feb ’21

Code Block class LocalNotificationManager: ObservableObject {
    
    @Environment(\.managedObjectContext) private var viewContext
    var meetings: Item?
    
    var notifications = [Notification]()
    
    init() {
        UNUserNotificationCenter.current().requestAuthorization(options: [.alert, .badge, .sound]) { granted, error in
            if granted == true && error == nil {
                print("Notifications permitted")
            } else {
                print("Notifications not permitted")
            }
        }
    }
    
    func sendNotification(title: String, subtitle: String?, body: String, time: Date, id: UUID, repeatPattern: String) {
        let content = UNMutableNotificationContent()
        content.title = title
        if let subtitle = subtitle {
            content.subtitle = subtitle
        }
        content.body = body
        content.sound = UNNotificationSound.default
        
        let triggerDate = time - 5 * 60
        if repeatPattern == "Daily" {
            let trigger = UNCalendarNotificationTrigger(dateMatching: Calendar.current.dateComponents([.second], from: triggerDate), repeats: true)
            let request = UNNotificationRequest(identifier: "\(id)", content: content, trigger: trigger)
            UNUserNotificationCenter.current().add(request, withCompletionHandler: nil)
        } else if repeatPattern == "Weekly" {
            let trigger = UNCalendarNotificationTrigger(dateMatching: Calendar.current.dateComponents([.timeZone, .weekday, .hour, .minute, .second], from: triggerDate), repeats: true)
            let request = UNNotificationRequest(identifier: "\(id)", content: content, trigger: trigger)
            UNUserNotificationCenter.current().add(request, withCompletionHandler: nil)
        } else if repeatPattern == "Monthly" {
            let trigger = UNCalendarNotificationTrigger(dateMatching: Calendar.current.dateComponents([.timeZone, .weekOfMonth, .weekday, .hour, .minute, .second], from: triggerDate), repeats: true)
            let request = UNNotificationRequest(identifier: "\(id)", content: content, trigger: trigger)
            UNUserNotificationCenter.current().add(request, withCompletionHandler: nil)
        } else if repeatPattern == "None" {
            let trigger = UNCalendarNotificationTrigger(
                dateMatching: Calendar.current.dateComponents([.timeZone, .year, .month, .day, .hour, .minute], from: triggerDate), repeats: true)
            let request = UNNotificationRequest(identifier: "\(id)", content: content, trigger: trigger)
                    UNUserNotificationCenter.current().add(request, withCompletionHandler: nil)
        }
        let center = UNUserNotificationCenter.current()
        center.getPendingNotificationRequests(completionHandler: { requests in
            for request in requests {
                print(request)
                
            }
        })
    }
}

0

Answer 7

OOPer OP

Feb ’21

I guess I have chosen a bad term.
Please show your code responding to notifications.

0

Answer 8

Claude31 OP

Feb ’21

You could call from

Code Block func userNotificationCenter(_ center: UNUserNotificationCenter, willPresent notification: UNNotification, withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void) {
        
        if notification.request.identifier == requestIdentifier {
            completionHandler( [.alert,.sound,.badge])
            // schedule next notification here 
        }
    }

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Answer 9

Hu is I OP

Mar ’21

I'm a little confused as to what you mean by calling that function. Where would I call that function? And what is the requestItentifier in that function?

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Answer 10

Claude31 OP

Mar ’21

This function is called when a notification is presented.

If you want to filter on a specific notification, you set requestIdentifier to the appropriate request identifier that was defined at creation.

0

Answer 11

OOPer OP

Mar ’21

I'm a little confused as to what you mean by calling that function. Where would I call that function? And what is the requestItentifier in that function?

Seems you do not know how to respond to user notifications.
Please show your code instantiating your LocalNotificationManager.

0

Answer 12

LowRight OP

Apr ’21

Apple's interface here is awful. All that is necessary is to add a start date. Why can't they add it?????? It would make developers' lives so much easier. 😡

2