Objective-C: How do you access parent properties from subclasses?

Question

If I have this class defined, how do I access the someObject property in subclasses without compiler errors?

@interface MyBaseClass
  // someObj         


        

Answer 1

that's how you access them. how you declare them is what's biting you:

@interface MyBaseClass : NSObject
@property (nonatomic, readwrite, retain) NSObject *someObject;
@end

this is the normal way to declare a new objc class.

by adding the parentheses (instead of declaring the superclass - NSObject in this case), you have declared a class extension, which is probably not visible to the subclass (via inclusion).

you will probably never need to declare a root class in objc:

@interface MyBaseClass // << superclass omitted
@property (nonatomic, readwrite, retain) NSObject *someObject;
@end

NSObject (or a subclass of, assuming you're target apple's systems) should be the base class unless you're very experienced and know what a root class is for.

class extensions are often used to 'simulate' private interfaces. by simulate, the compiler doesn't enforce this, as it would be enforced in other languages. for example, all messages are still dynamic, although the subclass may (unknowingly) override methods in your extensions, if declared with the same selector.