Contents

module Traitorous
  module Converter
    # MethodKeyedUniformedHash is meant to take an array of a simple data
    #   structures and convert each into a uniform class, and then will call a
    #   key_method on that class and use it as the key in the returned hash.
    #
    # Exported data will be converted into an array calling do_export on each
    #   element
    class MethodKeyedUniformHash
      attr_accessor :key_method, :uniform_class
      # @param key_method [Symbol] the method to call on the uniform_class instance
      #   to generate the key in the returned hash
      # @param uniform_class [Class, #new] the class to instantiate with each
      #   element of the do_import array
      def initialize(key_method, uniform_class)
        @key_method = key_method
        @uniform_class = uniform_class
      end

      # The import instantiates each element of the array as an instance of
      #   the uniform_class, the key is determined by calling key_method on the
      #   instance and then they are joined to the result hash as a key,
      #   instance pair.
      # @param arr_data [Array] the array of data to instantiate
      # @return [Hash] hash containing key, instance pairs
      def do_import(arr_data)
        out = {}
        arr_data.each do |elem_data|
          obj = uniform_class.new(elem_data)
          out[obj.send(key_method)] = obj
        end
        out
      end

      # @param hsh_data [Hash<obj,#export>] keys are ignored
      # @return Array each element of the values of hsh_data has #export called
      #   on it.
      def do_export(hsh_data)
        hsh_data.values.map{|instance| instance.export }
      end
    end
  end
end

Version data entries

1 entries across 1 versions & 1 rubygems

Version	Path
traitorous-0.2.0	lib/traitorous/converter/method_keyed_uniform_hash.rb