RubyCocoa introduction

presented by Chris Chan (iGPSD) organized Cocoahead HK

Ruby is ...

developed by Yukihiro “Matz” Matsumoto in the early 90’s

a object oriented scripting language

everything is an object ( example: 1.even? )

dynamic type script language

the foundation of well known web development framework ( Ruby on Rails )

Objective-C ...an object-oriented extension of C

a dynamically-typed language

use message handler rather than function call

add support of C++ and become Objective-C++

Objective-C++ supported by official GCC since gcc 4.1

Cocoa is ...

a framework for building desktop applications

developed by NeXT in 1990’s

Apple adopt NeXT technology and built OSX

RubyCocoa is ...a bridge between the Objective-C and Ruby programming language

import the Objective-C classes on demand

work by forwarding Messages by using proxy objects

able to do the method overriding to Objective-C method

History for RubyCocoa

started in 2001 by Hisakuni Fujimoto

in 2002, registered on SourceForge

in 2006, joined by developer from Apple, RubyCocoa presentation made during WWDC

in 2007, included and supported in Mac OSX Leopard

information from wikipediahttp://en.wikipedia.org/wiki/RubyCocoa

RubyCocoa Usage

Ruby Script that make use of the native Cocoa API ( like make use of image preview to convert image )

Interactive to the system directly

use as a tool for prototyping as you can use irb to study the Cocoa in runtime

RubyCocoa weakness

Performance is not as good as Objective-C/Cocoa Application

Ruby isn’t thread-safe, developer may need to handle concurrent update by using locks

Ruby cannot dispatch native threads

How to get start

For developer using Mac OSX Leopard, you have built-in support for the RubyCocoa

For developer using Tiger or earlier, you can download and install RubyCocoa

svn co https://rubycocoa.svn.sourceforge.net/svnroot/rubycocoa/trunk rubycocoa

ruby install.rb configruby install.rb setupsudo ruby install.rb install

Syntax different between Objective-C and Ruby(I)

in Objective-C, sending a message named play to an object named sound

[sound play];

in Ruby, the corresponding message

sound.play

Syntax different between Objective-C and Ruby(II)

in Objective-C, messages include arguments, the arguments are interleaved with tags that describe them

[sound initWithContentsOfFile:filename byReference:false];

in Ruby, the corresponding messagesound.initWithContentsOfFile(filename, :byReference, false)

*argument tags are included as parameters of the message, in this case is “byReference”

Ruby irb

By using irb, you can try using rubycocoairb(main):001:0> require 'osx/cocoa'=> trueirb(main):002:0> s = OSX::NSString.stringWithString "hello" => #<OSX::OCObject:0x370976 class='NSCFString' id=0x114dee0>irb(main):003:0> s.objc_methods.sort=> ["CI_affineTransform", "CI_copyWithZone:map:", "CI_rect", "UTF8String", ...

http://www.rubycocoa.com/an-introduction-to-rubycocoa/4

Example Code

Example code provided by Apple can found in here /Developer/Examples/Ruby/RubyCocoa/

ActiveRecord Binding Example

/Developer/Examples/Ruby/RubyCocoa/MailDemo/MailDemoActiveRecordBindings/

RealTime Image filter Demo

/Developer/Examples/Ruby/RubyCocoa/CITransitionSelectorSample

You can build the next Clip it!

/Developer/Examples/Ruby/RubyCocoa/MiniBrowser

More resource

http://www.rubycocoa.comThey have many great tutorial for beginner like me

http://rubycocoa.sourceforge.net/HomePage

The latest Source for RubyCocoa

Books

Cocoa(R) Programming for Mac(R) OS X (3rd Edition)http://www.amazon.com/exec/obidos/ASIN/0321503619/bignerdranch-20

Ruby Cocoa ( beta book ) expected release date Nov 2008http://www.pragprog.com/titles/bmrc/rubycocoa

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