Ruby and Rails Jason Dew
AITP Ruby And Rails Talk
Jan 17, 2015
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Ruby and RailsJason Dew
Ruby
pure OO
42.methods.sort
beautiful
def fib n return 0 unless n > 0 return 1 if [1,2].include? n fib(n-1) + fib(n-2)end
puts fib(10) # => 55
Symbols
roygbiv = [:red, :orange, :yellow, :green, :blue, :indigo, :violet]
some_hash = { :bar => "bar", :life => 42 }
blocks
array = [42, "bar", ["x"]]
result = array.map do |element| element * 2end
puts result.inspect# => [84, "barbar", ["x", "x"]]
classes
class Monster def initialize @hitpoints = 400 end
def hitpoints @hitpoints end
end
dragon = Monster.newdragon.hitpoints # => 400
modules
module Bar def bar "baz" endend
include Barputs bar # => "baz"
open classes
class Array
def sum_of_squares inject(0) do |ss, element| ss + element ** 2 end end
end
[2,4,8,1,13,7].sum_of_squares # => 303
define_method
class Player
[:dexterity, :piety].each do |attribute| define_method(attribute) do puts "returning your #{attribute}" end
define_method("#{attribute}=") do |value| puts "setting #{attribute} to #{value}" end end
end
my = Player.newmy.dexterity # => returning your dexteritymy.piety = 3 # => setting piety to 3
method_missing
class Caster
def sissy_slap puts "your enemy laughs" end
def method_missing name, *args puts "#{name}: spell unknown" end
end
me = Caster.newme.sissy_slap # => "your enemy laughs"me.fireball # => "fireball: spell unknown"
singleton classes
class Barend
bar = Bar.new
def bar.bar "baz"end
bar.bar # => "baz"
Rails
RESTful routing
# config/routes.rb
ActionController::Routing::Routes.draw do |map| map.resources :barsend
Rails action Path method HTTP verb URL
index bars_path GET /bars
show bar_path(42) GET /bars/42
new new_bar_path GET /bars/new
create bars_path POST /bars
edit edit_bar_path(42) GET /bars/42/edit
update bar_path(42) PUT /bars/42
destroy bar_path(42) DELETE /bars/42
HAML
# RHTML version<?xml version="1.0" encoding="utf-8" ?><!DOCTYPE html ...>
<html> <head> <title>Page Title</title> </head> <body> <h1>Page Header</h1> <div id="content"> <p class="news"> Some news content </p> </div> </body></html>
# HAML version!!! XML!!!
%html %head %title Page Title
%body %h1 Page Header #content %p.news Some news content
ActiveRecord
migrations
class CreateUsers < ActiveRecord::Migration def self.up create_table 'users' do |t| t.belongs_to :area t.string :login, :email, :name t.string :crypted_password, :salt t.timestamps end end
def self.down drop_table 'users' endend
associations
class Team < ActiveRecord::Base has_many :playersend
class Player < ActiveRecord::Base belongs_to :teamend
gamecocks = Team.find_by_name("Gamecocks")gamecocks.players # => returns player array
has many through
class Reader < ActiveRecord::Base has_many :feeds, :through => :subscriptionsend
class Feed < ActiveRecord::Base has_many :readers, :through => :subscriptionsend
class Subscription < ActiveRecord::Base belongs_to :reader belongs_to :feedend
ars_technica = Feed.find(42)ars_technica.readers # => some large integer
polymorphic models
class Client < ActiveRecord::Base has_many :addreses, :as => :addressableend
class Provider < ActiveRecord::Base has_many :addresses, :as => :addressableend
class Address < ActiveRecord::Base belongs_to :addressable, :polymorphic => trueend
Client.first.addresses.build Address.newProvider.first.addresses.build Address.new
# migrationcreate_table :addresses do |t| t.string :street, :city, :zip_code t.references :addressable, :polymorphic => true # ^^ creates addressable_id # and addressable_typeend
plugins
restful_authenticationhttp://github.com/technoweenie/restful-authentication/tree/master
http://railscasts.com/episodes/67
./script/generate authenticated user sessions
ym4r-gmhttp://github.com/bitbckt/ym4r-gm/tree/master
easy google maps integration
# controller def index @map = GMap.new "map_div" @map.control_init :large_map => true, :map_type => true @map.center_zoom_init [75.5, -42.56], 4
marker = GMarker.new [75.6, -42.467], :title => "title", :info_window => "bar" @map.overlay_init marker end
# view<html> <head> <%= GMap.header %> <%= @map.to_html %> </head>
<body> <%= @map.div %> </body></html>
attachment_fuhttp://github.com/technoweenie/attachment_fu/tree/master
has_attachment :storage => :s3
SC Ruby ConferenceOctober 18th, 2008
Columbia, SC
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