Example code: Parse JSON data of 10,000 items into Core Data objects on iOS, with a background operation queue.
The video is now up here: https://vimeo.com/81466705
Extra-credit challenges (not covered in this tutorial):
- Add an
NSDictionarywith the JSON
idas the key, and
NSManagedObjectIDas your values. (You can get it via a fetch for all objects of that entity.) Use the objectIDs in your mapping methods to look for an existing object for each JSON
id. If it already exists, you'll want to update the properties. If it doesn't exist, create the object. Does this adequately avoid duplicate objects? How would you guarantee that?
- Add relationship mapping. (Hint: create a class method, returning a dictionary, similar to what we used for attributes.) Return a single managed object, or a set of them, depending on the relationship type. This mapping will also need to be recursive, for any nested relationships. How would you implement this, but still keep it fast?
- There's plenty of performance improvements to be squeezed out of this example. You could likely make it faster by reducing the number of
save:calls to your child context, and/or increasing the number of objects that are mapped to a context and operation before calling