module BikePOA
  module Helpers
    module ForceField
      FORCED_FIELDS = {}
      def self.included(base)
        base.send :extend, ClassMethods
      end

      def []=(property, value)
        transform = FORCED_FIELDS[property.to_sym]
        value = transform.call(value) if transform
        super(property, value)
      end

      module ClassMethods
        def force_integer(field)
          FORCED_FIELDS[field.to_sym] = lambda { |value| Integer(value) }
        end

        def force_utf8(field)
          FORCED_FIELDS[field.to_sym] = lambda do |value|
            new_value = value.encode('utf-8','iso-8859-1')
            (new_value.length == value.length)? new_value : value
          end
        end
      end
    end
  end
end