ruby18hirakata

18th Ruby/Rails Meeting – Hirakata

What is Ruby

• Everything is Object.
• Open Class – you can extend every class
• Block – do … end (or { ... } )
• Useful classes:
  • Numeric, String, Symbol, Array, Hash, Regexp, Range

Class and Instance

link_to('',{:page => 2})
link_to '', {:page => 2}
link_to '', :page => 2

Rails

• CoC (Convention over Configuration)
• DRY (Don’t Repeat Yourself)

Sample application – BBS

$ rails -d sqlite3 bbs && cd bbs
$ script/generate model Comment
%% edit app/models/comment.rb
%% edit db/migrate/001_create_comments.rb
$ rake db:migrate

better use scaffold_resource , it will create model, controller and the migration

The Ruby “Saho”

how to look “beautiful”. “busaho” – mazui ;)

Basics

• object
• block
• duck typing
• metaprogramming

“Busaho”

• The code is not gentle for the programmer
• overloading (in C++ and Java it’s usual)
• creating classes just for the classes themself (overwork)
• just copy-paste from some design patterns
• difficult method names
• eval() is not the evil, it’s the LAST weapon

what to use for binary data – pack() and unpack() ? pack library?

Game programming with Ruby – MyGame library

Dan-san, dGames, http://dgames.jp/dan/

There is a book – “starting game programming with ruby” + CD

Concepts

• SDL-based (Ruby/SDL)short code (multiplatform)
• everything is object (character, blocks, tree, sky etc.)
• designed for begginers
• to be easy and “tanoshii” ;)

Install

• SDL
• Ruby
• Ruby/SDL
• MyGame

For Windows: ActiveScriptRuby, download and install Ruby/SDL

install_mygame.rb

Other: mygame-0.9.1.tar.gz

Usage

• Bootstrap – (require ’’)
• Main loop – block (do..end), 60 times per sec (60Hz)
  • clear screan
  • wait()
  • create object (render)
  • display object
• Using display object
• Keys
  • key_pressed?()
  • new_key_pressed?()

Sample

require 'mygame/boot'
Image.render 'sample.png', :x => 100, :y => 100
Image.render 'sample.png', :x => 100, :y => 200

image = Image.new('sample.png')
image.x = 50
image.y = 100
image.scale = 2.0
image.angle = 90
image.alpha = 128
image.render

counter = 0
main_loop do
  image.render
  image.x += 1       # moving the object (sliding)
  image.angle += 8   # rotation

  # using keys
  image.x += 8 if key_pressed?(Key::RIGHT)
  image.x -= 8 if key_pressed?(Key::LEFT)
  image.y += 8 if key_pressed?(Key::DOWN)
  image.y -= 8 if key_pressed?(Key::UP)

  counter += 1 if new_key_pressed?(Key::SPACE)
  Font.render(counter)
end

Internationalization in Ruby

Ruby-GetText-Package

8 steps in internationalization

application → .pot file → ja, pl → .mo

1. vim config/environment.rb
2. vim app/controllers/application.rb
3. vim Rakefile
4. rake updatepo
5. (make po files from the .pot file)
6. rake makemo

require 'gettext/rails'
....

Ujihisa-san’s slides on SlideShare

Rails service

PatchService – http://www.patchservice.net/