Apple Programming: User Defaults

Just started to look at some Apple Xcode application examples. That's a whole new huge framework for OS X. One application is about user defaults. In Windows there are many ways to store application defaults or values such as Registry, XML file, Ini file or Active Directory.

In Mac OS X, Apple provides a plist and bundle for user preferences and in Objective-C, there are some classes can be used to get user default values, NSUserDefaults for example:

NSUserDefaults *defaults;
// Get all the defautls for the current app
defaults = [NSUserDefaults standardUserDefaults];
// Register 2 defaults in case they are not available in user defaults
// Note, the registerDefaults does not change defaults.
[defaults registerDefaults:[NSDictionary dictionaryWithObjectsAndKeys:
 @"Joe", @"first_name",
 @"NO", @"is_married",
 nil]];
//... 

NSString firstName;
BOOL married;

// the following two calls will return the user's individual preferences,
// if they are available. Otherwise, it will just return the values we
// registered previously. Saves us some hassle!
firstName = [defaults stringForKey:@"first_name"];
married = [defaults boolForKey:@"is_married"];

That's quit difference way to do in Mac. Very interesting! Some good links about User Preference Defaults:

• O'Reily Mac DevCenter.com: Mac OS X's Preferences System (and More!)


• Apple Developer Center: NSUserDefaults Class Reference


• CocoaDev(WikiWikiWeb) article: NSUserDefaults