Local notification not arriving

Question

I am running background codes to check if there is any changes to a website and if there is a change a local notification to alert the user. However, when i run the code and try it out the local notification does not arrive. This is the code in my appDelegate.m

- (void)applicationDidEnterBackground:(UIApplication *)application {
    NSLog(@"Has Entered Background");
    timerCountDown = [NSTimer scheduledTimerWithTimeInterval:60.0 target:self selector:@selector(backGroundParsing) userInfo:nil repeats:YES];
}

- (void)backGroundParsing {
    //This is where my background checking happens. I deleted the code here to make it shorter.
    if (totalNumberOfEvents > totalNumberOfEvetsRecorded) {
                                NSLog(@"Notificatoin sent");
                                NSString *finalNumberOfEventsRecorded = [NSString stringWithFormat:@"%d",totalNumberOfEvents];
                                NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
                                [userDefaults setObject:finalNumberOfEventsRecorded forKey:@"finalRegisteredNumberOfEvents"];
                                UILocalNotification *notifyUserAboutNewEvent = [[UILocalNotification alloc] init];
                                [notifyUserAboutNewEvent setFireDate:[NSDate dateWithTimeIntervalSinceNow:1]];
                                [notifyUserAboutNewEvent setTimeZone:[NSTimeZone defaultTimeZone]];
                                [notifyUserAboutNewEvent setAlertBody:@"New event has been organised"];
                                [[UIApplication sharedApplication] setScheduledLocalNotifications:[NSArray arrayWithObject:notifyUserAboutNewEvent]];
                            }
}

I do log "Notification sent" but i do not receive any notification. Is there something missing or something wrong? I do not have any other code in my other void actions.

EDIT After what @rckoenes had said i edited my code to this.

- (void)application:(UIApplication * _Nonnull)application
performFetchWithCompletionHandler:(void (^ _Nonnull)(UIBackgroundFetchResult result))completionHandler {
    [self backGroundParsing];
}

- (void)backGroundParsing {
    //This is where my background checking happens. I deleted the code here to make it shorter.
                            if (totalNumberOfEvents > totalNumberOfEvetsRecorded) {
                                NSLog(@"Notificatoin sent");
                                NSString *finalNumberOfEventsRecorded = [NSString stringWithFormat:@"%d",totalNumberOfEvents];
                                NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
                                [userDefaults setObject:finalNumberOfEventsRecorded forKey:@"finalRegisteredNumberOfEvents"];
                                UILocalNotification *notifyUserAboutNewEvent = [[UILocalNotification alloc] init];
                                [notifyUserAboutNewEvent setFireDate:[NSDate dateWithTimeIntervalSinceNow:1]];
                                [notifyUserAboutNewEvent setTimeZone:[NSTimeZone defaultTimeZone]];
                                [notifyUserAboutNewEvent setAlertBody:@"New event has been organised"];
                                [[UIApplication sharedApplication] setScheduledLocalNotifications:[NSArray arrayWithObject:notifyUserAboutNewEvent]];
                            }
                        });
     }];
    [searchEventsTask resume];
}

However, i still do not receive the notification. I am getting an warning when i simulate the background fetch. This is the warning appearing in my NSLog Warning: Application delegate received call to -application:performFetchWithCompletionHandler: but the completion handler was never called. Is this warning normal when i simulate background fetch? My notification still does not appear. How would i fix it?

Answer 1

In iOS 8+, you have to user's permission for local notifications. Add the following line in your application didFinishLaunchingWithOptions method:

[[UIApplication sharedApplication] registerUserNotificationSettings:[UIUserNotificationSettings settingsForTypes:UIUserNotificationTypeAlert|UIUserNotificationTypeBadge| UIUserNotificationTypeSound categories:nil]];