Question

I’m extending the functionality of a class with a subclass, and I’m doing some dirty stuff that make superclass methods dangerous (app will hang in a loop) in the context of the subclass. I know it’s not a genius idea, but I’m going for the low-hanging fruit, right now it’s gonna save me some time. Oh it’s a dirty job, but someone’s gotta do it.

Bottom line, I need to either block that method from outside, or throw an exception when it’s called directly to the superclass. (But I still use it from the subclass, except with care).

What would be the best way to do this?

UPDATE —

So this is what I went for. I’m not self-answering, as Boaz’ answer mentions multiple valid ways to do this, this is just the way that suited me. In the subclass, I overrode the method like this:

- (int)dangerousMethod {   [NSException raise:@'Danger!' format:@'Do not call send this method directly to this subclass'];   return nil; } 

I’m marking this as answered, but evidently that doesn’t mean it’s closed, further suggestions are welcome.

Answer 1

Just re-implement the unsafe method in your subclass and have it do nothing or throw an exception or re-implement it as safe, just as long as the new implementation doesn’t call the unsafe superclass method.

For the C++ crew in here: Objective C doesn’t let you mark methods as private. You can use its category system to split up the interface into separate files (thus hiding ‘private’ ones), but all methods on a class are public.