title: Synchronize Core Data with paginated Web Service
body: <p>So here's my problem. I have a pinterest-like application with a collection view that shows images.The "pins" al downloaded from a web service and stored in core data. This web service returns the data organized in pages.</p>
  
  <p>What's the correct way to face this problem? If data were all stored in core data, I could implement as NSFetchedResultsController to fetch a batch of 10 or 20 pins, but each batch needs to make the appropriate request to the web service. I've also been looking into NSIncrementalStore, which also seems promising, but I still don't know how would that work.</p>
  
  <p>Right now, I have the web service working, the core data model implemented and a special class called DataManager that is responsible of the managedObjectContext, inserting, fetching, deleting, etc., from the database. I'm implementing the FetchedResultsController creator inside this class, but I still don't understand how to implement the incrementalStore or the web service call.</p>
  
  <p>Any idea on how to implement this architecture will be highly appreciated.</p>
  
  <p>Best regards</p>