Question

I’m trying to make a category adopt a protocol, and I’m having a problem with what seems like a simple thing.

The interface declaration is:

@interface UIView (UIViewCategory) <DesiredProtocol> 

And I was assuming the implementation declaration should be the same:

@implementation UIView (UIViewCategory) <DesiredProtocol> 

But this gets a yellow warning in XCode, with the message: “Protocol qualifiers without ‘id’ is archaic”.

So should the declaration be:

@implementation UIView (UIViewCategory) id<DesiredProtocol> 

??

I can’t find reference for this specific issue. Much thanks for all replies.

Answer 1

You don’t need the protocol list on an @implementation block, whether it’s a category or not.

@implementation UIView (UIViewCategory)
...
@end