This is my note about iOS Application development which is originally managing event data ( Calendar or Reminder) to make sure be more easy UI for me.
To get Calendar or Reminder List from iOS device, EKEventStore class is basement to access to those database. And in that data base there are some datasource. EKSource class contains data source definition like “iCloud”, “Default”,
These definition might work for permission to read & write the event. I will keep to investigate it.