What are good sources of knowledge / information about the implementation of objective-C and cocoa/ cocoa-touch?

Question

I've been developing for iOS for some time now, I think I have a good grasp of the cocoa-touch framework but I feel I am missing some nuggets about the underlying implementation of objective-C and cocoa-touch. e.g. recently when having an issue with allocations several posters pointed out some of the finer points of iOS implementation that made the issue I was seeing much clearer (and meant I understood how to resolve the issue properly)

I would like to know of any books, online-references or just good sources of knowledge providing an insight into the underlying implementation of objective-C and cocoa-touch that would allow me to gain a greater and more complete understanding of the framework, platform and language, under the hood. Anyone ??

Answer 1

Planet Cocoa aggregates several blogs related to Objective-C and Cocoa. I’m not sure if it includes all of the following blogs but they’re certainly worth following:

• NSBlog by Mike Ash
• bbum's weblog-o-mat
• Landon Fuller’s blog
• ridiculous_fish

If you’re not afraid of source code, Apple keep an Open Source Web site. Part of Core Foundation is there (CF), as well as the Objective-C runtime (objc), dyld and cctools. The LLVM project is also open source.

Answer 2

That's a difficult question to answer. I found the book Cocoa Design Patterns by Erik Buck and Don Yacktman a very good read. It talks about Cocoa on Mac OS X, but most of it is also applicable to iOS. The book explains many of the most used and important design patterns and approaches of the framework, and it often offers a good background on why a specific feature is designed as it is.

For very detailed looks under the hood, Mike Ash's regular blog posts in his Friday Q&A section cannot be recommended highly enough. Mike has recently published an ebook of all his posts over the last few years.