class FieldsField < Field
  def typecast(hash, record)
    ChangeSensitiveHash.new(record, name, fields_from_hash(hash, record))
  end
  
  def untypecast(hash, record)
    return {} unless hash.respond_to?(:to_hash)
    hash.to_hash.each_with_object({}) do |(name, field_obj), fields|
      next unless field_obj.is_a?(Field)
      fields[name.to_s] = field_obj.options
    end
  end
  
  def from_json(hash, record)
    # return {} unless hash.is_a?(Hash)
    #       hash.each_with_object({}) do |(name, options), fields|
    #         fields[name.to_s] = Field.from_options(name, options).options
    #       end
    fields_from_hash(hash, record)
  end
  
  private
    def fields_from_hash(hash, record)
      return {} unless hash.is_a?(Hash)
      hash.each_with_object({}) do |(name, options), fields|
        fields[name.to_s] = Field.from_options(name, options)
      end
    end
end

Field::TYPES['fields'] = FieldsField