requestAccessToEntityType - once or every time?

Question

EKEventStore *eventStore = [[UpdateManager sharedUpdateManager] eventStore];

if ([eventStore respondsToSelector:@selector(requestAccessToEntityType:completion:)])
{
    [eventStore requestAccessToEntityType:EKEntityTypeEvent completion:^(BOOL granted, NSError *error)
     {
         if (granted)...

I want to ask the user for permission to add an event to his calendar. After it's granted do I need to ask for permission again when I want for example to remove an event (in another session after the app was closed and reopened) or is it just a want time thing?

If it's a one time thing, can I just put it in ViewDidLoad at first lunch just to "get rid of it" ?

Answer 1

You only need to call it once:

BOOL needsToRequestAccessToEventStore = NO; // iOS 5 behavior
EKAuthorizationStatus authorizationStatus = EKAuthorizationStatusAuthorized; // iOS 5 behavior
if ([[EKEventStore class] respondsToSelector:@selector(authorizationStatusForEntityType:)]) {
    authorizationStatus = [EKEventStore authorizationStatusForEntityType:EKEntityTypeEvent];
    needsToRequestAccessToEventStore = (authorizationStatus == EKAuthorizationStatusNotDetermined);
}

if (needsToRequestAccessToEventStore) {
    [eventStore requestAccessToEntityType:EKEntityTypeEvent completion:^(BOOL granted, NSError *error) {            
        if (granted) {
            dispatch_async(dispatch_get_main_queue(), ^{
                // You can use the event store now
            });
        }
    }];
} else if (authorizationStatus == EKAuthorizationStatusAuthorized) {
    // You can use the event store now
} else {
    // Access denied
}

You shouldn't do that on the first launch, though. Only request access when you need it and that isn't the case just until the user decides to add an event.