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Next up is Erik Michaels-Ober. He is the second most handsome Ruby programmer in the world.
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He is going to talk to us about GUI programming with MacRuby.
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GUI programming is a sticky situation, so I hope that you provide some clarity.
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And now, Erik!
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GUI programming with MacRuby. Hey everybody.
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So, my mother is a journalist, and when I was very young, she instilled in me this idea that there are only a handful of words in the English language that you can use to ask a question. If you answer all those, then there are no questions left to be answered. I’m basically going to run through all these points on MacRuby, and if there are any questions at the end, I’ll just take that as a personal affront to my mother. These are the only questions.
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So first, who am I? This is my given name, but you might know me on the internet as sf_eric—Twitter, GitHub, Gmail, IRC, etc. I’m currently in the middle of a one-year fellowship at a non-profit organization called Code for America. Yeah, Code for America! We're working to make government more efficient, transparent, and open. It’s basically the best thing ever. I get paid to write open-source software all day, using Ruby. You can too!
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We just opened applications for our 2012 fellowship, so if anyone's interested in that, please come up and talk to me at some point during the conference. I can give you more information and even a t-shirt. We have great t-shirts!
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I also write a lot of open-source code, not necessarily related to fixing government. You probably use at least one line of code that I’ve written at some point—so you’re welcome.
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And just to be clear, I’m not a MacRuby expert. I’ve never submitted a patch to MacRuby, and I’m not on the core team. However, I am currently developing a MacRuby app called Hubcap.
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Basically, it’s a social GitHub client, so think of it as a third-party Twitter desktop client, but it's just for your friends who write code so you can keep tabs on them and see what code they’re writing.
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These are the real heroes for MacRuby. You should follow them. Also, the last thing on the list is the MacRuby Develop mailing list, which is really active and a great place to start if you’re interested in diving in and getting questions answered.
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Now, the what: what is MacRuby? MacRuby is a few things, but first and foremost, it’s a complete implementation of Ruby 1.9. You can think of it sort of like JRuby, except instead of running on the Java Virtual Machine, it runs right on top of macOS core technologies.
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It runs on the Objective-C runtime and uses the Objective-C garbage collector, which turns out to be vastly superior to the Ruby garbage collector, even in Ruby 1.9, primarily because it’s multi-threaded. Garbage collection can happen on a separate background thread, so it never interferes with your main thread.
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There is no global interpreter lock in Objective-C, so it has great performance just like JRuby. MacRuby also uses LLVM, which is more like a compiler infrastructure than a virtual machine.
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It compiles code into Objective-C bytecode through a Just-In-Time (JIT) compilation process. You can use IRB the same way you do now, and it will work great. There’s also ahead-of-time compilation, so you can bundle your applications and ship them out as packages.
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All Ruby apps should run in the MacRuby interpreter. Not everything you write for MacRuby will run in every other Ruby interpreter.
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I just want to give a really quick minimalistic demo. It’s not getting into any of the GUI features at all, but it’s just proving that MacRuby is, as I say, a real Ruby.
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Let me see if I can get this to work. Can you all see that?
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Let me see if I can make that bigger. Let’s try another one.
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Can everyone see this? Those are basically side by side, similar size, and big enough font.
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So I’m using RVM, and on this side is Ruby 1.9.2, and on this side, I’ll make it MacRuby, which is the latest version of Ruby 0.10.
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I’m just going to open up IRB on both of these. Looks about the same.
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If you have a string in Ruby 1.9 and you have a string in MacRuby, they are totally the same.
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So great, if I ask for that string’s class in Ruby 1.9, anyone want to venture a guess as to what it’s going to say? So that actually changed, I think, between MacRuby 0.5 and 0.6. It’s actually going to say String. I just blew your mind, I know.
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But what do you think is going to happen if I say MacRuby.class over here? The superclass of that in Ruby is Object. And for this side, some of you said NSObject or NSString; you’re both wrong. correct. It’s an NSMutableString.
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So the superclass of a Ruby string in that Ruby is NSMutableString. Anyone know if I super one more time what I’m going to get? So you get an NSString. If I go up one more time, great.
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So everything is an object, or everything is an NSObject as the case may be. Basically, anything you can do in Ruby, you can do in MacRuby.
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Let’s say I want to capitalize that string, so I can say food.upcase. Good. I can do the same thing over here.
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So if I want to see what methods are on String in Ruby 1.9, I need to say foo.methods. You're going to see almost exactly the same list. It’s not 100% identical, but it’s basically the same list. If I sort them, you can actually do a one-to-one comparison. There seems to be a few more methods on the MacRuby side, but they’re basically the same. What’s really cool in MacRuby is you can do this: I can say methods true true.
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So the first true indicates whether to include all the methods in the superclasses as well, and by default, that’s true. You’re going to get the same number of methods, right? But if I say false, then nothing. If I say true here, I get the same methods.
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But if I say true true, and if I give it the second true, you can't do this on this side. It will say 'wrong number of arguments.' But on this side, it’ll give me all of the Ruby methods that you can call on String, and also all of the Objective-C methods that you can call on an NSString.
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If I say methods.size for foo, it’s going to give me 168. If I say methods true true, size is going to give me a lot more. Okay, let’s take a look at some of those.
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So they’re these ugly Objective-C things, but what’s cool is that you can actually call them. Just like I can say foo.upcase, I can say foo.uppercaseString.
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It does the same thing. It totally works! You can invoke methods in the normal Ruby method invocation way. That might not seem awesome, but it's awesome because you have all the power of Ruby. You can call any Ruby method, and you can also call any Objective-C method and mix and match. You can have classes that inherit from NSObject or NSMutableString or anything like that and extend those using Ruby. I think that’s really cool.
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But that’s not really the fun stuff. The fun stuff is GUI programming, which is what this talk is all about.
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What’s the keyboard shortcut to just...Oh, there we go. Is that playing? Okay, great!
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This is probably all complicated by the fact that I’m running the Lion Developer Preview, which I’m not allowed to say anything about. But you can take from that what you will.
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Great! So MacRuby, in addition to being a complete implementation of Ruby 1.9, also lets you do two other things.
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One is that you can write scripts to control existing GUI applications. If you want to write a script that updates your status in iChat or does anything really, you can use it in the same way you would use Automator on the Mac but with the full power of a real programming language like Ruby.
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Then you can also create new GUI applications. That seems like an exciting thing you might want to do, but why should you care? There’s already a language existing to script Mac applications, called AppleScript, and there’s already a language for creating new Mac desktop applications called Objective-C.
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So what do you need Ruby for?
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I’m going to tell you a secret. I need everyone just to lean in because I can’t say it on the mic. Listen, here’s the secret: Apple’s not very good at making programming languages.
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Who is good at making programming languages? I think this guy is. So why do I say that? What’s not so good about AppleScript? Well, AppleScript is really a toy language. It’s not object-oriented. It doesn’t have blocks and lacks most of the features you’d want in a real programming language, like regular expressions, which you just take for granted in Ruby.
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So I think it’s fair to say that given equal availability, if you had to choose fairly between AppleScript and writing an application in Ruby with MacRuby, you would choose MacRuby.
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MacRuby has a great scripting bridge framework that allows you to easily hook into any application and write scripts to your heart’s desire.
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Maybe you’re thinking, you know, I don’t really care about writing scripts for other people’s GUI applications. I want to create my own. For that, Apple has a language for you called Objective-C.
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Objective-C is not a toy language. You can tell that by looking at the name and seeing the word C in it. So you say, "Okay, this must be a robust and powerful language because it’s C," and that’s mostly true. But I would make the case that it’s hampered by being constrained by the syntax of C.
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What’s nice is that because MacRuby uses LLVM and compiles your applications down into Objective-C bytecode, you get the performance benefits of Objective-C without having to write C code.
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Let me make the case that Ruby is actually better than Objective-C; it's just a nicer language.
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Let’s look at method invocation. This is how you invoke a method in Ruby, which should look familiar to everyone in the room. Can anyone suggest how you can make this simpler?
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So you could get rid of the dots. But how would you know that you put a colon after a method?
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You could make it simpler by getting rid of the dot, but you still need some syntax to differentiate parameters.
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This is how you do method invocation in Objective-C. I think this is kind of gross, but maybe it’s not so bad. Can anyone think of a way to make this simpler?
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You could use parentheses and get rid of the dot. You could lose the semicolon too.
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In Objective-C, because it is bound by C syntax, everything must be syntactically valid C.
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This is Ruby, how you initialize and sign an array. This should look pretty simple, right? Hard to imagine too much simpler.
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So this is how you do exactly the same in Objective-C.
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If you’re okay with doing this, then definitely Objective-C is the language for you. If you’re a Ruby developer, like I was, it seems out of reach.
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For me personally, the thing that attracted me to MacRuby was being able to code in Ruby and generate something beautiful like a desktop application.
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RubyCocoa was Apple’s first attempt at supporting Ruby. They built this Ruby to Objective-C bridge.
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But according to Apple, RubyCocoa is not viable anymore because they’re investing a lot into MacRuby development, paying developers full time.
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There are many ways to write a client for the Mac; you don’t have to use Objective-C at all.
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I’m not going to spend a lot of time convincing you not to write Java apps for desktop clients. You probably already know why.
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The promise of Java is that you write the code once and it runs anywhere. But that always seemed a bit wrong about Java client apps!
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You don't get that problem with MacRuby. MacRuby apps look and feel exactly the same as apps written in Objective-C because they are native Cocoa applications.
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So, do not write Java apps. Java wasn't the solution to write once, run anywhere; the solution is the web.
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Maybe you're thinking, okay, I could use one of these fancy new JavaScript frameworks for doing rich apps. I'm not going to tell you not to write web apps; they are terrific.
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Not all apps have to be web apps, and certain functionalities are just not possible with web apps.
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For example, if I have a Bluetooth device and want to write a Mac app that communicates with it, it’s tough to do that in a web app.
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So, this is sort of the what. Moving on to the when. This is exciting! Just yesterday, MacRuby 0.10 was released.
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It’s a great release! It’s stable! 1.0 is coming really soon. Features have basically been frozen, and the core team is polishing up the APIs.
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They’re going to do a couple of small releases just to improve stability and performance leading up to the target of 1.0.
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That’s awesome! MacRuby, whatever version it may be at the time, will hopefully be included in Mac OS 10. It’s already included in the developer previews.
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The only problem is that currently, it’s a private framework.
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If you want to use MacRuby in your app, you have to bundle all of MacRuby into your app. You can’t just assume it’s there in the operating system.
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If Lion becomes a public framework, you would be able to assume it was there, so that would be great.
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If you have to bundle MacRuby into your application, you start off with a 50 Megabyte footprint of your application before writing any code just to include Ruby.
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If it were a public framework and you could assume it was there, then every MacRuby application would be 50 Megabytes smaller!
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So it seems worthwhile to advocate for that.
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So why? I think I already gave you some reasons from a programmer's perspective.
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From a programming perspective, I hope I’ve convinced you that the syntax is nice, and it’s a good way to go if you want to build a GUI application!
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Here’s a number of reasons why.
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One is you already know Ruby. If you're sitting in this room, there’s a strong chance you know more Ruby than any of the other languages mentioned.
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Number two: you can use any existing Ruby libraries. The libraries that you’ve already written, there are vast gems on rubygems.org.
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MacRuby is also all Ruby 1.9. Especially if you’re bundling the application, you can use the cool new hash syntax without worrying about breaking code.
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It allows you to use all the new syntactic features in the latest version of Ruby.
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There’s also no global interpreter lock, so it has the potential to be really fast.
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It has a much better garbage collector than even the latest version of Ruby!
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Here are some benchmarks. The x-axis is confusing—there are just a bunch of different benchmarks, and I couldn’t figure out how to rotate them.
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Each bar represents a benchmark relative to Ruby 1.9. If you see scores like 4, 5, or 6, it means it’s six times faster than Ruby 1.9.
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Not everything is faster, but it makes it clear that MacRuby outperforms Ruby 1.9 in most scenarios.
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You aren’t taking a performance hit by writing MacRuby applications; many times, it's a performance gain!
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A lot of people would be well served to run their existing non-MacRuby applications on MacRuby because it’s such a fast Ruby.
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The Mac App Store is a tremendous new opportunity for app developers.
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I think Pixelmator reported making a million dollars in the first 20 days of sales on the App Store—that’s an amazing statistic!
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You might think, oh, maybe I should do an iPhone app or maybe an iPad app; those are much bigger markets.
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That's true; more people have iPhones and iPads than Macs, but that’s offset by the fact that Mac users are willing to pay more for apps.
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You can do greater things without being limited by the screen real estate of a phone, making the design constraint interesting.
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There’s a great opportunity to capitalize on this wave of apps, and there’s also a lot less competition!
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Before all these barriers for writing Mac desktop apps existed, now they’re sort of going down.
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Now the opportunity is increasing!
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So, how do you do it? You can go to macruby.com and download it.
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It’s just a package, like any other Mac DMG or maybe a ZIP file. You go through an installer, and it works.
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If you’re running RVM, make sure you have the latest version of RVM, and then just say 'rvm install macruby'!
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I’ve been assured that there’s a 20 gig broadband pipe, so if you all want to put that to the test now, just type those two commands.
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One of the dependencies you might need is LLVM, which you can install with Homebrew or MacPorts.
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You can also build it from source if that’s your thing.
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You also need Xcode tools, which you probably already have.
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So, if you don’t have that information yet, get it!
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What are some other resources you should know about? There’s a great book that Matt Aimonetti is working on called 'Ruby: The Definitive Guide.' It’s an O’Reilly book.
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He’s writing it live on the internet, so you can see every time he updates it. It’s totally free, so just go check it out.
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The first nine chapters are mostly fleshed out, and he’s updating as new releases of MacRuby come out.
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That book will presumably be published shortly after MacRuby 1.0 goes live.
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There’s another book called 'MacRuby in Action,' which you can also get early. It hasn’t been published yet, but you can pay 20 bucks and get a PDF of whatever state it's currently in.
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Despite what I said about Objective-C earlier, having knowledge of Cocoa will definitely help you.
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You can call any of the Cocoa methods in Ruby in MacRuby. Having a fundamental understanding of what's happening under the hood helps, and this is an awesome book!
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If you have any feedback about this talk, feel free to send me an email, tweet, or something like that.
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You can follow me on GitHub. If you don't have a computer, you can call me. My telephone number is 415-312-2382.
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Just kidding! Don’t call me.
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That’s it! I think I have exactly one minute for questions. Maybe one or two?
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Yes, okay, sorry, real fast. First one: ruby gems that are not compatible with MacRuby?
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Stuff that has native extensions; we are working on that.
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The second question is about distributing an app that is using, you know, not mine.
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Okay, I’ll review the questions for those who can hear it. The first question was... If gems aren’t compatible, that’s above Ruby. In theory, MacRuby should be able to handle those.
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So if you find a gem that’s not compatible with MacRuby and it won’t install, you should file that as a bug.
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The second question was about the bundling. If somebody doesn't have Lion, Apple may decide to make MacRuby a public framework.
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So if they expose some interface that allows you to include it, you’d then have all of the code stack; you wouldn’t have to bundle it.
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What you would have to do for earlier releases of Mac OS X, hopefully, they’d also release point version updates for Snow Leopard.
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But if not, you just have two separate binaries.
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You could distribute a package for Lion and a very lightweight package for pre-Lion.
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Great! I think I’m out of time, is that right?
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Yes? Okay, great! Thanks, everybody!
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