iPhone - Why does the documentation say UIImageView is NSCoding compliant?

Question

Ideally an NSCoding compliant class will work as expected using encodeWithCoder: and initWithCoder: (at least I thought so till recently) without the developer having to bot

Answer 1

The documentation is misleading -- UIImage does not conform to NSCoding as you've stated. You can work around it (in a primitive way) by doing the work yourself:

@interface UIImage (NSCoding)
- (id)initWithCoder:(NSCoder *)decoder;
- (void)encodeWithCoder:(NSCoder *)encoder;
@end

@implementation UIImage (NSCoding)
- (id)initWithCoder:(NSCoder *)decoder {
  NSData *pngData = [decoder decodeObjectForKey:@"PNGRepresentation"];
  [self autorelease];
  self = [[UIImage alloc] initWithData:pngData];
  return self;
}
- (void)encodeWithCoder:(NSCoder *)encoder {
  [encoder encodeObject:UIImagePNGRepresentation(self) forKey:@"PNGRepresentation"];
}
@end