How to set iBeacon to broadcast a local notification only once for a single device?

Question

I'm presenting a local notification whenever we're entering or exiting a region in

locationManager:didRangeBeacons:inRegion method of CLLocationManagerDelegate:

something like this..

//local notification sent from transmitter to receiver 

switch (beacon.proximity) 
{  
 case CLProximityNear:   
   message = @"You are near the ibeacon device";  
   bgColor = [UIColor blueColor];  
   break;  
 case CLProximityImmediate:   
   message = @"You are very closer to the device..";  
   bgColor = [UIColor colorWithRed:.0f green:.0f blue:230.0f alpha:1.0f];  
   break; 
}

Now when the receiver detects the transmitter and sends the local notification, the receiver will be getting the local notifications. Additionally I want to set the local notification for one day i.e., receiver should receive the message from transmitter only once. Valuable suggestions are highly appreciated.

Note: I'm using iPad mini as the Transmitter & iPhone 5 as the receiver.

Answer 1

You need to keep track of the times each beacon was detected in your didRangeBeaconsInRegion method and ignore certain beacons using a software filter if they have been seen recently.

An example of how to do this is shown here. The core of that is:

  - (void)locationManager:(CLLocationManager *)manager didRangeBeacons:(NSArray *)beacons inRegion:(CLRegion *)region
  {
      for (CLBeacon *beacon in beacons) {
          Boolean shouldSendNotification = NO;
          NSDate *now = [NSDate date];
          NSString *beaconKey = [NSString stringWithFormat:@"%@_%ld_%ld", [beacon.proximityUUID UUIDString], (long) beacon.major, (long) beacon.minor];
          NSLog(@"Ranged UUID: %@ Major:%ld Minor:%ld RSSI:%ld", [beacon.proximityUUID UUIDString], (long)beacon.major, (long)beacon.minor, (long)beacon.rssi);

          if ([beaconLastSeen objectForKey:beaconKey] == Nil) {
              NSLog(@"This beacon has never been seen before");
              shouldSendNotification = YES;
          }
          else {
              NSDate *lastSeen = [beaconLastSeen objectForKey:beaconKey];
              NSTimeInterval secondsSinceLastSeen = [now timeIntervalSinceDate:lastSeen];
              NSLog(@"This beacon was last seen at %@, which was %.0f seconds ago", lastSeen, secondsSinceLastSeen);
              if (secondsSinceLastSeen < 3600*24 /* one day in seconds */) {
                  shouldSendNotification = YES;
              }
          }

          if (shouldSendNotification) {
              [self sendLocalNotification];
          }
      }
  }

Answer 2

Yes, it is possible. Try the below code:-

NSUserDefaults * userDefault = [NSUserDefaults standardUserDefaults];
BOOL alreadySent = [userDefault boolForKey:[NSString stringWithFormat:@"%@",region.identifier]];

if(!alreadySent){

    //Already Send the notification for today
    [userDefault setBool:YES forKey:[NSString stringWithFormat:@"%@",region.identifier]];

    //Set the date for this region, you will need this date in order to set the BOOL to No later.
    [userDefault setObject:[NSDate date] forKey:[NSString stringWithFormat:@"%@Date",region.identifier]];

    //TODO: Send the Local Notification here
}

//TODO: Somewhere else, you will have to check if the date for that particular region.identifier
//if the date is already over 24 hours, set the Bool to NO

Answer 3

When you detect a beacon and notify the user, you can store the current date in a persistent store, such as NSUserDefaults. Then when you next detect that beacon/region you can check the date and if it is "today", do nothing. If it isn't "today" then notify the user again and update the stored value