ActiveRecord model without a backing table. Useful for View Models, and other plain old objects with validations, and other ActiveRecord facilities like associations, etc.

tableless_model.rb

module ViewModel
  def self.included(base)
    base.extend ClassMethods
    base.class_inheritable_accessor :columns
    base.columns = []
  end

  module ClassMethods
    def column(name, sql_type = :text, default = nil, null = true)
      columns << ActiveRecord::ConnectionAdapters::Column.new(name.to_s, default, sql_type.to_s, null)
    end
  end

  def save(validate = true)
    validate ? valid? : true
  end
end

# example

class Foo < ActiveRecord::Base
  include ViewModel

  column :bar
  column :blah
end