Stuffed Table Columns

stuffed_table_columns.rb

# Represent states such as 'active', 'disabled', etc in the DB as an int
#
# Use like so:
#
# class MyModel < ActiveRecord::Base
#   include StuffedTableColumns
#   stuffed_column :status, *(%w(active inactive blocked disabled banned))
# end

# TODO: use method_missing to match the column name
module StuffedTableColumns
  def self.included(base)
    base.extend ClassMethods
  end

  def status
    if read_attribute(self.class.instance_variable_get(:@column_name)).blank?
      read_attribute(self.class.instance_variable_get(:@column_name))
    else
      self.class.instance_variable_get(:@column_options)[read_attribute(self.class.instance_variable_get(:@column_name))]
    end
  end

  def status=(status)
    if self.class.instance_variable_get(:@column_options).include? status
      write_attribute(self.class.instance_variable_get(:@column_name), self.class.instance_variable_get(:@column_options).index(status.downcase))
    elsif status.blank?
      write_attribute(self.class.instance_variable_get(:@column_name), status)
    else
      raise "Error writing status attribute: Not one of #{self.class.instance_variable_get(:@column_options).join(', ')}"
    end
  end

  module ClassMethods
    def stuffed_column(column, *options)
      @column_options = options
      @column_name = column

      scope "with_#{column}", lambda { |status|
        index = options.index(status.downcase)
        where(status: index)
      }
    end
  end
end