1. Ruby on Rails
#2 Ruby
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2. What is Ruby
• Programing language
• Dynamic
• Multi‑paradigm: OOP, functional,
imperative, reflection
• Influenced by: Perl, Smalltalk, Lisp,
C++, Python ...
• Created in the mid‑1990s
• "I wanted a scripting language that was more Yukihiro Matsumoto (Japan)
powerful than Perl, and more object‑oriented than Python. That's why
I decided to design my own language."
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3. Deeper in the Ruby
• Latest stable version 1.9.3‑p286
• RoR 3.0 has bugs with Ruby 1.8.7 p248 and p249
• RoR 3.0 has conflicts with 1.9.1
• Use RoR 3.x with Ruby 1.9.>=2
• Ruby License
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4. Philosophy
• Everything is object (numbers, primitives,
methods and classes too)
• Every object has class and superclass
• The root of class hierarchy is Object
• Ruby has not static methods or variables
• All instance variables are private
• Interfacejava mechanism through modules
• Module (like class, but) has not variables
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5. Hello world
#!/usr/bin/ruby #!/usr/bin/ruby
# coding: utf‑8
# coding: utf‑8
def hello_world();
puts "Hello World!" puts "Hello world";
end;
hello_world();
#!/usr/bin/ruby
# coding: utf‑8
def hello_world
puts "Hello world"
end
hello_world
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6. Ok, now install Ruby
• http://en.wikibooks.org/wiki/Ruby_Programmin
g/Installing_Ruby
• All examples work with
Ryby 1.9.3p125
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7. Little bit of syntax
#One line comments
=begin multiline comments (=begin and =end in one
column)
=end
'It's string' and "It's string" and %q!It's string too!
a # variable
$b # global variable
@c # instance variable
Constant # but u can change it if bribe conscience
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8. Functions
def this_function()
#function_body
end
def this_function
#function_body
end
def ==(variable)
#overload operator
end
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9. Classes
class Your_class
@test # by default private
def test_method #by default public
#code
end
private #yep, private modificator like in C++
def test_method2 #private
#code
end
public
def test_method # public
#code
end
end
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10. Code blocks
def test
print "<<"
yeild "Wolrd"
end
test do |x|
print " Hello #{x} ! >>"
end
# result << Hello World ! >>
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11. Libraries
• All through packages
• Self package system (gem)
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12. Some features
• Ruby has interactive interpretator irb
• Ruby slow with Windows (Ruby isn't optimized for
windows, because most core developers use Linux)
• Interpretator encoding is utf8
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13. Links
• http://www.ruby‑lang.org/en/ ‑ Ruby official
site
• http://en.wikibooks.org/wiki/Ruby_Programmin
g/Installing_Ruby ‑ install Ruby
• http://www.ruby‑doc.org/ ‑ documentation
• http://tryruby.org/ ‑ interactive for learning ruby
for beginers
• http://rubymonk.com/ ‑ use it after truruby (for
beginers too)
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14. Literature in RU
• Michael Fitzgerald "Learning Ruby": superficial
• David Flanagan and Yukihiro Matsumoto "The
Ruby Programming Language" : detailed book
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15. Literature in EN
• David A. Black "The Well‑Grounded Rubyist" :
good book
• Dave Thomas, Chad Fowler, Andy Hunt
"Programming Ruby 1.9 (3rd edition): The
Pragmatic Programmers' Guide" : good book too
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16. Additional literature
• Russ Olsen "Design Patterns In Ruby" : patterns
for rubists
• William C. Wake, Kevin Rutherford "Refactoring
in Ruby" : all in name
• Jay Fields, Shane Harvie, Martin Fowler
"Refactoring: Ruby Edition" : Fowlers's
"Refactoring" with examples for Ruby
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