Chapter 11. Application Settings

A setting, or preference, for an application contains two pieces: a key and a value. The key refers to a unique value identifying the setting, for example musicVolume. The value refers to the value stored for the given key. Working with settings involves creating and modifying key/value pairs within property lists.

Property lists are XML-formatted files that store the key and value pairs that make up an application's settings. They are nothing new to Apple developers, as they are supported by most recent versions of Mac OS X, and can be read and written to directly from dictionary classes without actually having to parse a file.