Hi I'm looking into iPhone development, and Objective-C is not be my preferred language. As far as I can see at this moment Ruby cannot be used to talk to Cocoa Touch at the moment on the iPhone.
So my question is, am I wrong? Can I use Ruby on the iPhone to develop Cocoa Touch applications. And what is the future looking like for Ruby on the iPhone?
In the iPhone OS, mprotect() will fail if you try to use it to mark writable sections of memory as executable. This breaks bridges like RubyCocoa (and probably MacRuby) that use libffi to create Objective-C method handlers at runtime. I believe that this is by design because it was not always the case.
Ultimately, this is more a matter of platform politics than technology, but a technical workaround for this exists. Instead of generating custom method handlers at runtime, precompile a pool of reconfigurable ones that are assigned as needed, essentially making the bridging process entirely data-driven. As far as I know, this is not yet being done in RubyCocoa or MacRuby.
Another significant thing to consider is that the compiled Ruby and RubyCocoa runtimes can be significantly larger than compiled Objective-C apps. If these libraries were available on the iPhone, this wouldn't be an issue, but for now, even if you had RubyCocoa working, you might not want to use it for apps that you distribute.
No, you are correct. Currently, and most likely for the foreseeable future, Ruby will not be an option, at least for AppStore applications. There's no reason you couldn't do this on a Jailbroken phone, but Apple is pretty wed to Objective C for official development.
You are better off as a programmer knowing a number of different languages - think of Objective-C as a good learning opportunity.
I've found that things you learn in other languages often make you a better programmer overall, and give you new insights into other languages you already know.
rhomobile is an option to run ruby code on the iPhone, but it's essentially web app development. A web server runs locally on the iPhone and your ruby code renders to standard client side web technologies (html/css/javascript).
Actually, the ruby cocoa bridge isn't awkward at all; things work remarkably smoothly, right down to connecting outlets in IB etc. The resulting code is down right beautiful.
As for iPhone development, if you want an official AppStore application, you're out of luck unfortunately. Apple dictated that iPhone is Obj-C/Cocoa Touch, and there's a clause in the SDK license saying that one of the things they will reject an app for is having a language interpreter/JIT compiler, so you couldn't add a ruby interpreter in your app yourself.
Off topic, but hilariously, this is why Flash for the iPhone is Adobe blowing smoke. They couldn't get a swf player onto the AppStore even if they wanted to, per Apple's license.
Take a look at http://www.appcelerator.com/products/titanium-mobile/ "Native iPhone and Android apps built with Web technologies."
Sounds good isn't it ? ;-)
I imagine it won't work right now, but I'd imagine that you'll eventually be able to use MacRuby to build iphone apps. Apple are putting a lot of work into it
Here's a link to an ADC article describing how to build normal cocoa apps
You don't have to use Objective-C to write iPhone apps. If you use QuickConnectiPhone, http://sourceforge.net/projects/quickconnect/, you can write it completely in JavaScript, CSS, and HTML and still have an installable application not a web app.
If you know ruby you are probably working with JavaScript already.
To see how to install it, run it, and other ideas go to tetontech.wordpress.com
There's an open-source Ruby-Cocoa bridge you might try to get working. But I gather that there's a bit of an impedance mismatch between Ruby and ObjC that makes it a bit awkward to use.
The Ruby Cocoa bridge probably will not work. Most of the bridges for dynamic languages need to generate executable thunks (either manually or with libffi). More limited bridges (for more static languages) may not have such issues.
In either event, bringing up a bridge is probably going to require becoming more familiar with the Objective C runtime than one would just learning how to write Cocoa Touch apps, which probably defeats the point of doing it in the first place.
