gistfile1.rb

module Readers
  # Maps key/value pairs from the data structure used to initialize a
  # Endeca object. Allows attribute renaming. Use a block to perform data
  # injunction on the value as it is set. Depends on an +attributes+ accessor
  # for the attributes hash.
  #
  # ==== Examples
  #
  #   # Specify basic attributes
  #   reader :title
  #
  #   # Attribute renaming
  #   reader :long_desc => :description
  #
  #   # Data injunction
  #   reader(:title => :upcased_title) { |title| title.upcase }
  def reader(*attrs,&block)
    hash = {}
    hash.update(attrs.pop) if Hash === attrs.last
    attrs.each do |attr|
      hash[attr] = attr
    end
    hash.each do |variable, method|
      variable = variable.to_s
      if block_given?
        define_method(method) do
          block.call(attributes[variable])
        end
      else
        define_method(method) { attributes[variable] }
      end
    end
  end

  # Typecasts attributes as integers.
  #
  # ==== Examples
  #   integer_reader :id, :rating
  def integer_reader(*attrs)
    reader(*attrs) { |value| Integer(value) }
  end

  # Typecasts attributes as BigDecimal
  #
  # ==== Examples
  #   decimal_reader :price
  def decimal_reader(*attrs)
    require 'bigdecimal' unless defined?(BigDecimal)
    reader(*attrs) { |value| BigDecimal(value.to_s) }
  end

  # Typecasts attributes as floats 
  #
  # ==== Examples
  #   float_reader :latitude, :longitude
  def float_reader(*attrs)
    reader(*attrs) { |value| Float(value) }
  end

  # Typecasts attributes as a Perly boolean ("0" == false, "1" == true")
  #
  # ==== Examples
  #   boolean_reader :price
  def boolean_reader(*attrs)
    reader(*attrs) { |value| value == "1" ? true : false }
  end
end