Now that we’ve made changes on disk, we need to notify the contexts of them.
In this example, it’s not strictly necessary. Most likely the user interface hasn’t touched any of these objects yet. If the objects haven’t been loaded into memory, then there’s no risk of a conflict. However, it’s best that we don’t assume they haven’t been loaded yet. Users can be very clever.
There are two basic ways to notify our NSManagedObjectContext instances of the changes. We can reset each object individually in each NSManagedObjectContext that it might be associated with, or we can use the new API that was added in iOS 9.0. Let’s look at the harder way first.
If the situation calls for it, we ...