Understanding model objects

As you learned in Chapter 14, Getting Started with MVC and Table Views, a common design pattern for iOS apps is Model-View-Controller, or MVC. To recap, MVC divides an app into three different parts:

• Model: This handles data storage, representation, and data processing tasks.
• View: This is anything that is on the screen that the user can interact with.
• Controller: This manages the flow of information between the model and the view.

Let’s revisit the design of the Journal List screen that you saw during the app tour, which looks like this:

Figure 15.1: Simulator showing the Journal List screen from the app tour

Build and run your app, and the Journal List screen will look like this:

Figure 15.2: Simulator showing the Journal List screen from your app

As you can see, all the cells currently display placeholders. Based on the MVC design pattern, you have partly completed the implementation of...