iOS Programming: The Big Nerd Ranch Guide, Second Edition

Moving Homepwner to Core Data

Your Homepwner application currently uses archiving to save and reload its data. For a moderately sized object model (say, under 1000 objects), this is fine. As your object model gets larger, however, you will want to be able to do incremental fetches and updates, and Core Data can do this.

The very first step is to add the Core Data framework to your project. Select the Homepwner target and under Build Phases, open the Link Binary With Libraries build phase. Click the + button to add the Core Data framework.

Figure 17.1  Add Core Data framework

The model file

In a relational database, we have something called a ...