saturnflyer

require 'resolv'

class EmailValidator < ActiveModel::EachValidator
  def validate_each(record, attribute, value)
    if Resolv::DNS.new.getresources(value.split("@").last, Resolv::DNS::Resource::IN::MX).empty?
      record.errors[attribute] << (options[:message] ||  "does not have a valid domain")
    end
  rescue Resolv::ResolvError, Resolv::ResolvTimeout
    record.errors[attribute] << (options[:message] ||  "does not have a valid domain")
  end

saturnflyer

mod = Module.new
        mod.module_eval %{
          def fill_out_#{name}(value)
            checkbox = find(:#{name})
            if (#{name}_checked_values.include?(value) && !checkbox.selected?) || 
                (#{name}_unchecked_values.include?(value) && checkbox.selected?)
                
              checkbox.click
            end  
          end

saturnflyer

def with_conditions(method_name, computed_value)
  if method_name.to_s == 'address' && !computed_value.nil?
    address.renderable?
  else
    super
  end
end  

saturnflyer

class Exception
  def cause_message
    cause && cause.message
  end
  
  def cause_backtrace
    cause && cause.backtrace
  end
end

saturnflyer

Introduction .....................................................................................................6
  What This Is ..................................................................................................................8 
  What This Is Not ...........................................................................................................8
Lost In Translation...........................................................................................9
  Our First Bugs..............................................................................................................10
Object Orientation ........................................................................................12
  Where We Are..............................................................................................................12    
  Where We’ve Been .......................................................................................................20 
  Where We’re Going ....................

saturnflyer

require 'delegate'
# Public: This class initializes a presenter object.
# The presenter wraps a given object and a view object and will forward
# method calls to each. By default, any unknown method will be passed
# to the first object.
# Any methods that need to be sent to the view, may be done explicitly.
#
# Examples:
#
#   # Inside a controller you create a helper method to access this object

saturnflyer

1. Ruby Delegate.rb Secrets
2. Simple presenters to clean up views
3. Ruby Forwardable in Depth
4. how it works
5. SingleForwardable
6. identifying responsibility leaks with if
7. enforcing encapsulation
8. seeing the westward flow and heading east
9. ActiveSupport::Delegation, the Rails approach to forwarding
10. The Casting gem and why it's different from SimpleDelegator

saturnflyer

seed = [[0,0],[0,1],[0,2]]
puts "First generation:"
puts seed.to_s

# Point surrounding a given point
perimeter = ->(x, y){
    [
      [x - 1, y + 1], [x, y + 1], [x + 1, y + 1],
      [x - 1, y    ],             [x + 1, y    ],
      [x - 1, y - 1], [x, y - 1], [x + 1, y - 1]

saturnflyer

  require 'delegate'
  class SpecialFormatter < SimpleDelegator

    def initialize(user, profile)
      super(user)
      @profile = profile
    end
    attr_reader :profile

    def self.maybe(*names)

saturnflyer

def custom_mail_to(email, link_text, i18n_subject_key)
  mail_to(email, link_text, :subject => I18n.t(i18n_subject_key, :email => email))
end