NSKeyedUnarchiver setClass example ios

setClass :forClassName:

Adds a class translation mapping to the receiver whereby objects encoded with a given class name are decoded as instances of a given class instead.

- (void)setClass:(Class)cls forClassName:(NSString *)codedName

Parameters of [NSKeyedUnarchiver setClass]

cls

The class with which to replace instances of the class named codedName.

codedName

The ostensible name of a class in an archive.

Discussion

When decoding, the receiver’s translation map overrides any translation that may also be present in the class’s map (see setClass:forClassName:).

Example of [NSKeyedUnarchiver setClass]

 MyViewController *controller = [[[MyViewController alloc] init] autorelease];
   NSKeyedUnarchiver *unarchiver = [[[NSKeyedUnarchiver alloc] initForReadingWithData:[NSKeyedArchiver archivedDataWithRootObject:controller]] autorelease];
   [unarchiver setClass:[MyNavigationBar class] forClassName:@"UINavigationBar"];
   controller = [unarchiver decodeObjectForKey:@"root"];

Example of [NSKeyedUnarchiver setClass]

UIViewController *tempController = [[[UIViewController alloc] init] autorelease];
UINavigationController *navigationController = [[[UINavigationController alloc] initWithRootViewController:tempController] autorelease];

NSData *archive = [NSKeyedArchiver archivedDataWithRootObject:navigationController];
NSKeyedUnarchiver *unarchiver = [[[NSKeyedUnarchiver alloc] initForReadingWithData:archive] autorelease];
[unarchiver setClass:[CustomNavigationBar class] forClassName:@"UINavigationBar"];
UINavigationController *customNavigationController = [unarchiver decodeObjectForKey:@"root"];

UIViewController *contentController = [[[ContentViewController alloc] init] autorelease];
customNavigationController.viewControllers = [NSArray arrayWithObject:contentController];