ios - prevent app from sending notification if already one there - ios

Question

I can't seem to find it and I'm not sure how to Google it. In my app I use background fetches to do checks and if there is new data, I send a notification to the user using UILocalNotification. Now how do I prevent the app from sending a new notification to the user if there is already one there? I'm now ending up with 5 of the same notifications when I don't look at my phone for some hours.
Thanks!

Answer 1

You can use UIApplication's property scheduledLocalNotifications
Here's the sample code:
NSMutableArray *notifications = [[NSMutableArray alloc] init]; [notifications addObject:notification]; myApp.scheduledLocalNotifications = notifications;
//Equivalent: [myApp setScheduledLocalNotifications:notifications];
UIApplication *myApp = [UIApplication sharedApplication];
NSArray *eventArray = [myApp scheduledLocalNotifications];
for (int i=0; i<[eventArray count]; i++)
{
UILocalNotification* oneEvent = [eventArray objectAtIndex:i];
NSDictionary *userInfoCurrent = oneEvent.userInfo;
NSString *uid=[NSString stringWithFormat:#"%#",[userInfoCurrent valueForKey:#"uid"]];
if ([uid isEqualToString:uidtodelete])
{
//Cancelling local notification
[myApp cancelLocalNotification:oneEvent];
break;
}
}
NSArray *arrayOfLocalNotifications = [[UIApplication sharedApplication] scheduledLocalNotifications] ;
for (UILocalNotification *localNotification in arrayOfLocalNotifications) {
if ([localNotification.alertBody isEqualToString:savedTitle]) {
NSLog(#"the notification this is canceld is %#", localNotification.alertBody);
[[UIApplication sharedApplication] cancelLocalNotification:localNotification] ; // delete the notification from the system
}
}
Hope this would help figure out the solution.

Answer 2

The best way to avoid having to cancel something it in the first place is also to simply NOT sending it.
Find a way to know if the user has been notified before, and if he has, don't notify again :)
This is cleaner, more efficient, will last forever, and won't backfire, ever.
Also, this answers your question of "not sending a notification again" instead of sending it and cancelling afterwards, which isn't a good idea if you think about it.