Core Data is, in many ways, a replacement for our application’s model layer. It is much more than just storage; it also manages the life cycles of our data objects, tracks and validates any changes to our data, provides effortless undo support, and, yes, saves our data to disk. Furthermore, the
UIManagedDocument class simplifies and improves on Core Data by automatically setting up our Core Data stack, performing file read and writes on background threads, and adding simple iCloud Document syncing.
In this chapter, we will look at the technologies underlying both Core Data and
UIManagedDocument. Then we will replace Health Beat’s entire model layer with a
UIManagedDocument-based model. As you will see, this provides a much ...