Can I "manually" insert items into an AFIncrementalStore's cache?

Question

I have set up AFIncrementalStore to grab objects from a JSON service over the network and set its persistentStore to be an SQLite database. This all works fine.

Now what I want to do is add objects to that SQLite database out-of-band (from something other than the web service the AFIncrementalStore is pointing to), and have those additions reflected in the fetched results controllers created from the original managed object context.

I've created a managed object context with the original MOC as its parent and I can add objects to that and they're seen by the fetched results controller. But they're not saved to the AFIncrementalStore's SQLite db. Interestingly, AFIncrementalStore is seeing these objects as it was trying to save them back to the JSON service and complaining the correct endpoint didn't exist (I fixed this by overriding requestForInsertedObject:insertedObject to return nil.)

Anyone know how I achieve this?

Answer 1

It sounds like you have already found most of the answer. AFIncrementalStore checks for a nil response from requestForInsertedObject: in your AFRESTClient subclass. If that method returns nil, AFIS creates a permanent ID for the object, stores the object in the backing store and doesn't try to send it to the server again. This is all in the first section of executeSaveChangesRequest:withContext:error:.

Are you always calling save: on the parent ManagedObjectContext? If not, that would be the other reason it's not storing the object in SQLite. But then it shouldn't be trying to POST the object to the server either.

Answer 2

If you don't want to POST objects to the server you have to override methods

requestForInsertedObject:insertedObject
requestForUpdatedObject:updatedObject
requestForDeletedObject:deletedObject

Then when you call context's save: method your objects must be saved in the database. I'm using similar logic when I'm doing CRUD operations offline and it is working fine.