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

class Foo
  def self.say
    p "hello from Foo"
  end
end

module Bar
  def say
    super
    p "hello from Bar"

saturnflyer

module N
  def foo
    puts "N: foo" 
    super
  end
end

module O
  def foo
    puts "O: foo"