I'm working on an app that requires multiple asynchronous downloads and saving of their contents to Core Data entities. One of the downloads is large and noticed the UI was being blocked while creating/writing to the managed object context. My research led me to read up on concurrent Core Data setups and I started implementing one of these. But I'm running into issues and spending a lot of time correcting things.
Before I continue, I'm thinking about simply setting up a single MOC with NSPrivateQueueConcurrencyType. Nothing I read mentions doing this. This way I could optionally perform MOC operations in the background, or just use the main thread as usual while maintaining a single MOC.
Is this a good approach? If not, what is wrong with it? I doubt this is the right approach because if it is, NSPrivateQueueConcurrencyType dominates NSMainQueueConcurrencyType and there would be no reason to have the latter.
There is nothing wrong with using a NSPrivateQueueConcurrencyType MOC for background tasks.
But you will probably still need a NSMainQueueConcurrencyType MOC.
From the documentation:
The context is associated with the main queue, and as such is tied into the application’s event loop, but it is otherwise similar to a private queue-based context. You use this queue type for contexts linked to controllers and UI objects that are required to be used only on the main thread.
As an example, for a fetched results controller, you would use the
NSMainQueueConcurrencyType MOC.