Question

Suppose I have a simple DTO class like this:

@interface MYNugget
@property (nonatomic, copy) NSString *color;
@end

@implementation MYNugget
// automatic @synthesize
@end

And I then later want to store this object in another class in a way such that it is not modifiable (that is, make the color property readonly via a - (void)freeze or something.

What is the best way to accomplish this short of writing my own setters?

Answer 1

The standard way is to have to classes, one mutable and an immutable one.

@interface MYNugget
@property (nonatomic, copy, readonly) NSString *color;
@end

and

@interface MYMutableNugget : MYNugget
@property (nonatomic, copy, readwrite) NSString *color;
@end

Your other class would just expose a MYNugget property, ideally again as copy. That’s how we do it with NSString all the time.