Objective-C: Inject code into delegate method

Question

What I want

I want to add some logging code into my app without having to update all of my view controllers.

What I've tried

I attempted to add a category to UIViewController and override one of the delegate methods. However, this produced several warnings/errors.

Is there a way for me to inject code into all of my app's ViewControllers?

Answer 1

Look into method swizzling. It is a powerful tool and can save you a lot of time. Swizzle one of the methods you wish to have logs in, and then call the original method to have it do what it is originally supposed to.