gistfile1.rb

class User < ActiveRecord::Base
  ROLES = [
    'admin',
    'manager',
    'branch_manager',
    'planner',
    'employee',
    'customer'
  ].freeze

  # Define a method for each role: user.admin?, user.manager?, ...
  User.class_eval do
    User::ROLES.each do |state|
      define_method "#{state}?" do
        self.role == state
      end
    end
  end
end