Programming iOS 6, 3rd Edition

Address Book Interface

The Address Book UI framework puts a user interface, similar to the Contacts app, in front of common tasks involving the address book database. This is a great help, because designing your own interface to do the same thing would be tedious and involved. The framework provides four UIViewController subclasses:

ABPeoplePickerNavigationController

Presents a navigation interface, effectively the same as the Contacts app but without an Edit button: it lists the people in the database and allows the user to pick one and view the details.

ABPersonViewController

Presents an interface showing the properties of a specific person in the database, possibly editable.

ABNewPersonViewController

Presents an interface showing the editable properties of a new person.

ABUnknownPersonViewController

Presents an interface showing a proposed person with a partial set of noneditable properties.

These view controllers operate coherently with respect to the question of whether your app has access to the address book. For example, if the user has never granted or denied your app access to the address book, attempting to use ABPeoplePickerNavigationController will cause the system alert to appear, requesting access. If the user has denied your app access to the address book, the ABPeoplePickerNavigationController’s view will appear, but it will be empty (like Figure 30-2). ABNewPersonViewController, similarly, will lack interface for saving into the database if your app has been ...