NSKeyedArchiver category

Each method in the NSKeyedArchiver category corresponds to a method in the NSKeyedArchiver class, but provides a secure version of the functionality. For more information about the functionality and usage, see NSKeyedArchiver in developer.apple.com.

NOTE: The category methods return an NSError object. The methods set the properties on the object as described in NSError objects that secure Objective-C methods return.

The following table shows each added method and its corresponding method in NSKeyedArchiver.

Table 1. NSKeyedArchiver category methods

Method in category

Corresponding method in NSKeyedArchiver

 
+ (BOOL)archiveRootObject:
  (id)rootObject 
  toSecureFile:(NSString *)path
  error:(
      NSError *__autoreleasing *)error;
 
+ (BOOL)archiveRootObject:
  (id)rootObject 
  toFile:(NSString *)path;
 
+ (BOOL)archiveRootObject:
  (id)rootObject 
  toSecureFile:(NSString *)path 
  atomically:(BOOL)atomically
  error:(
      NSError *__autoreleasing *)error;
 
+ (BOOL)archiveRootObject:
  (id)rootObject 
  toFile:(NSString *)path 
  atomically:(BOOL)atomically;

Example:

The following example shows how to use NSKeyedArchiver and NSKeyedUnarchiver category methods to:

1. Create a secure archive file and write data to it from a mutable dictionary.
2. Read the contents of the secure archive file into another mutable dictionary.
NOTE: For brevity, the example does not include error handling. 
- (void)NSKeyedArchiverCategoryExample
{
	NSError *error;
 
	// Create and populate a mutable dictionary. 
	NSMutableDictionary *dict = [NSMutableDictionary dictionary];
 
	NSString *key1 = @"baseball";
	NSString *value1 = @"white";
	[dict setValue:value1 forKey:key1];
 
	NSString *key2 = @"basketball";
	NSString *value2 = @"orange";
	[dict setValue:value2 forKey:key2];
 
	// Archive the dictionary to a secure file.
	NSString *archiveName = @"/tmp/secureArchive";
		    [NSKeyedArchiver archiveRootObject:dict toSecureFile:archiveName error:&error];
 
	// Unarchive the secure file contents into another dictionary. 
	NSMutableDictionary *dictCopy = (NSMutableDictionary*)[NSKeyedUnarchiver 
					unarchiveObjectWithSecureFile:archiveName error:&error];
 
	// Note: The contents of NSMutableDictionary objects 'dict' and 'dictCopy' 
	// are identical.
 
}