Cocoa Grandfather

Question

Is it possible to access the superclass method of superclasses of objects (or grandfathers)?

For instance:

GrandFatherObject : NSObject
SuperObject : GrandFatherObject
SelfObject : SuperObject

From SelfObject:

- (void)overriddenMethod
{
  // For Self
  someCode();

  // For Parent
  [super overriddenMethod];

  // For GrandParent
  ???
}

I only have access to SelfObject (cannot change SuperObject or GrandFatherObject)

Answer 1

Yes, you can do it, but it requires a bit more code than just a call super.

More or less, it will be something like this:

#import <objc/runtime.h>

struct objc_super grandsuper;
grandsuper.receiver = self;
grandsuper.class = class_getSuperclass(class_getSuperclass([self class]));

//if _cmd has a non-struct return value:
id grandsuperReturnValue = objc_msgSendSuper(&grandsuper, _cmd, arg1, arg2, ...);

Answer 2

Why do you need this? You should rethink your class if you think this is necessary. Of course, you can always call superin the implementation of the parent class overriddenMethod.

, . . .

Answer 3

objc_msgSendSuper(), , , SelfObject, -

@interface SuperObject (ForSelfObject)
  - (id)grandFatherOverridenMethod;
@end

@implementation SuperObject (ForSelfObject)
  - (id)grandFatherOverridenMethod {
    return [super overridenMethod];
  }
@end

, SuperObject, , . - ?