Question

I am trying to write an objective-c framework and I would like to have methods and properties visible only within the framework. I know I could define them in a class extension inside the implementation file but then they will not be accessible by other classes.

One way I was thinking to do it was to define a category for example MyClass+Internals and make that header private. but make the MyClass.h header public. I was wondering if there was a better way of doing this. Also, I’m not sure you can define properties within a category I thought it was only methods. Thanks for any suggestions or feedback.

Answer 1

Say you have a class named “Foo”, then in “Foo_Framework.h”, create:

@interface Foo()
@property ....;
- .... method ....
@end

Then, make sure that “Foo_Framework.h” is imported before the @implementation Foo. That’ll cause the class Foo to be compiled with the extended interface found in said header file. That header can then be used throughout your framework. Just don’t make it available outside said framework.

You are correct that you can’t declare properties (that are synthesized) in a category. That was one of the primary motivations for the creation of class extensions, of which the above is an example.