How can I guarantee unique entries in a Core Data store in a shared app container used by both the host app and an extension?

Question

To ask my question effectively, let\'s first consider the exact scenario I\'m facing:

General Setup

• A host iOS 8 app.
• One or more

Answer 1

It seems like the simplest approach to this would be to simply avoid the multiple writers in the first place. Why not just drive your extensions entirely off cached data, and then only update your data store from your primary iOS app?