Repeating a Local Notification after every 14 days(two weeks)?

Question

In my app i've to set repetitive UILocalNotification. I'm able to set repeatInterval as daily, weekly etc by doing

UILocalNotification *localNotification = [[UILocalNotification alloc] init];
localNotification.repeatInterval = NSDayCalendarUnit; // or any other calendarUnit

Ok..it's fine, but i've to set repeatInterval for every 14 days. i came to know from this link that we can only use one of the NSCalendarUnit repeat intervals. So you can have a repeat interval of one minute or one hour or one day but not five minutes or three hours or 14 days. Any Idea about this limitation in iOS 5 or later(that article was written for iOS 4.0)?

Mafalda

Some how is it possible to use repeatInterval other than NSCalendarUnit? – Mafalda

Why not resolve this by using a calendar with a 14 day week? Seems like that ought to work. Then the biweekly (7 day week) turns into a simple weekly (14 day) repeat cycle. – Perforated

Answer 1

You can only set the repeat interval to a calendar unit. In order to get the right time interval you may have to set several notifications though.

If you for instance wanted a notification every 20 minutes you would have to create 3 notifications 20 minutes apart with a repeat interval of NSHourCalendarUnit.

The problem in your case is that the next thing up from the week unit is a month but a month is not exactly 4 weeks.

To actually set a notification for every 14 days you will have to create 26 notifications with a repeat interval of NSYearCalendarUnit.

Showy

thanks for your help but one more limitation of local notification is that we can use a max of 64 notifications only and i've to set repetitive of type daily, weekly, 14 days, monthly etc and here it is a possibility that notification count may cross limit of 64? – Mafalda

The max is a consideration but you have calendar types for daily, weekly and monthly so they will only need one notification each. If you are making use of a weekly, do you also need a 14 day notification? – Showy

yes, infect i need daily, by weekly(2 times a week),weekly, 14 day, and monthly repetition. – Mafalda

Ok.. i think it is the only way to achieve this, thanks for your help – Mafalda

You may want to consider only scheduling maybe a month in advance and then when the app is loaded check if you need to schedule another month in advance. If a user has not opened the app in a month they are probably not interested anymore... – Showy

@Bharat, do you have a link to the documentation where it mentions a limit on notifications please? – Dykes

Search for "firing 64 notifications" in developer.apple.com/library/ios/documentation/iPhone/Reference/… or see comments in blog.mugunthkumar.com/coding/… – Mafalda

Answer 2

You can cancel the notification and set a new one fire date at 14 days from now when handling the notification. i.e. when your app is running in the foreground, do it in:

(void)application:(UIApplication *)application didReceiveLocalNotification:(UILocalNotification *)notification

See this SO topic: Set repeatInterval in local notification

I've tried this way, and it works.

Sparid

this callback does not work if the application is in background and user do not dismiss the notification alertBody – Neral

Answer 3

In iOS 10, you can use UNTimeIntervalNotificationTrigger to repeat notification after every 14 days.

UNTimeIntervalNotificationTrigger* trigger = [UNTimeIntervalNotificationTrigger triggerWithTimeInterval:(14*24*3600) repeats: YES];
NSLog(@"td %@", trigger.nextTriggerDate);

UNNotificationRequest *request = [UNNotificationRequest requestWithIdentifier:identifier content:content trigger:trigger];

[center addNotificationRequest:request withCompletionHandler:^(NSError * _Nullable error) {
    if (error != nil) {
        NSLog(@"Something went wrong: %@",error);
    } else {
        NSLog(@"Created! --> %@",request);
    }
}];

Hope this will help anyone looking for this topic.

Azores