How to get rid of the 'undeclared selector' warning

Question

I want to use a selector on an NSObject instance without the need for an implemented protocol. For example, there\'s a category method that should set an error prop

Answer 1

While the correct answer likely lies in informing Xcode through imports or registering the selector that such a selector exists, in my case I was missing a semi-colon. Make sure before you "fix" the error that perhaps, the error is correct and your code isn't. I found the error in Apple's MVCNetworking sample, for instance.