Selectors or Blocks for callbacks in an Objective-C library

Question

Question

We\'re developing a custom EventEmitter inspired message system in Objective-C. For listeners to provide callbacks, should we require blocks or selectors and

Answer 1

I think the right thing to do is to implement both, use it as a client, and see what feels most natural. There are advantages to both approaches, and it really depends on the context and how you expect the SDK to be used.

The primary advantage of selectors is simple memory management--as long as the client registers and unregisters correctly, it doesn't need to worry about memory leaks. With blocks, memory management can get complex, depending on what the client does inside the block. It's also easier to unit test the callback method. Blocks can certainly be written to be testable, but it's not common practice from what I've seen.

The primary advantage of blocks is flexibility--the client can easily reference local variables without making them ivars.

So I think it just depends on the use case--there is no "objective right answer" to such a general design question.