create a custom calendar - ios

Question

I want to create a new custom calendar on iOS, in my application.
I search for some explications on how do it work. But my code doesn't work / the calendar is not created
EKEventStore *eventStore = [[EKEventStore alloc] init];
EKSource *theSource = nil;
for (EKSource *source in eventStore.sources) {
if (source.sourceType == EKSourceTypeLocal) {
theSource = source;
break;
}
}
NSString *identifier;
EKCalendar *cal;
if (identifier == nil)
{
cal = [EKCalendar calendarForEntityType:EKEntityTypeEvent eventStore:eventStore];
cal.title = #"MyCustomCalendar";
cal.source = theSource;
[eventStore saveCalendar:cal commit:YES error:nil];
NSLog(#"cal id = %#", cal.calendarIdentifier);
}
else
{
cal = [eventStore calendarWithIdentifier:identifier];
}

Answer 1

I'm not sure if you are completely set on using EKCalendar, but you do not need to to make a calendar in iOS. You can design your own however you want with a UICollectionView or Buttons laid out dynamically. The important part is to make sure all of your dates are arranged correctly, which is not necessarily trivial. But, if you have a good way to get the first weekday for the first day of a given month, you can get it done. I followed this algorithm: http://en.wikipedia.org/wiki/Determination_of_the_day_of_the_week which seemed a bit complicated, but in practice was easy to code and reliable. Otherwise I believe apple has a 'firstWeekday' method/property you can try, but that didn't work for me. Once you have the right first weekday you can enumerate through the days of the rest of the month and put them how you want on your calendar.
It seems like you are unsure how to setup your calendar data with EKCalendar. I found a nice tutorial you may find useful:
http://oleb.net/blog/2012/05/creating-and-deleting-calendars-in-ios/
For more specific questions try the documentation, you can find it with a google search.
Otherwise, what kind of data export are you looking for? iCloud? Local? Are you working with an actual calendar provided or just saving something with all of your calendar data that another application can read?

Answer 2

The one possible way to get this issue is, mismatching calendar source type.
Since you've created the calendar with local source type, system could not find local source if you already synced your iCloud / gmail / exchange calendars.
So my suggestion is don't stick with local source and try to create the calendar in any available source. If you go for this approach, you'll also be ready for solving appropriate issues (like the case iCloud is synced but user has not given permission for iCloud-calendar sync).