Calling registerUserNotificationSettings multiple times

Question

I am developing an app for iOS 8 and utilizing interactive notifications. For that one has to register notification settings with categories. Problem is I have to schedule local notification at different point of my app based on user inputs. So the question is if call this code

UIUserNotificationSettings *mySettings =
[UIUserNotificationSettings settingsForTypes:types categories:[NSSet setWithObject:myCategary]];

[[UIApplication sharedApplication] registerUserNotificationSettings:mySettings];

multiple times with different "myCategories" will it overwrite my existing categories or add to previous registered for local notifications?

Answer 1

It will overwrite the old settings as UIUserNotificationSettings is singleton. Find more explanation here: ios 8 interactive notifications not showing actions

Answer 2

With the code above you ask user's permission to schedule notification. (The popup where he can choose: Don't allow or Allow app to send you push notification) This popup only shows up once, no matter what the user chooses. If the user chooses Don't allow, he can only change this option in Settings oh phone. However, once the user gives you approval to send notifications, you can schedule them from anywhere within the app.