serializer

gistfile1.txt

  module Serializer
    module Sti
      extend ::ActiveSupport::Concern

      included do
        class_attribute(:serializer_for_type_map, {})
        class_attribute(:_resolve_serializer_for_type_block)

        class << self
          alias :__new__ :new
        end

        def self.new(object, options={})
          type_specific_serializer = type_specific_serializer_for(object)

          if type_specific_serializer
            type_specific_serializer.new(object, options)
          else
            super(object, options)
          end
        end
      end

      module ClassMethods
        def inherited(subclass)
          super(subclass)

          class << subclass
            alias :new :__new__
          end
        end

        def look_for_type_specific_serializer?(object)
          object.class.inheritance_column && object[object.class.inheritance_column.to_sym]
        end

        def try_mapping_type?(type_name)
          self._resolve_serializer_for_type_block || serializer_for_type_map.key?(type_name) || serializer_for_type_map.key?(type_name.safe_constantize)
        end

        def resolve_serializer_for_type_with(&block)
          self._resolve_serializer_for_type_block = block
        end

        def type_specific_serializer_for(object)
          return nil unless look_for_type_specific_serializer?(object)

          type_name = object[object.class.inheritance_column]

          if try_mapping_type?(type_name)
            result = if self._resolve_serializer_for_type_block
              self._resolve_serializer_for_type_block.call(type_name)
            else
              self.serializer_for_type_map.fetch(type_name) {
                self.serializer_for_type_map.fetch(type_name.safe_constantize)
              }
            end
          else
            nil
          end
        end
      end
    end
  end
  

    class WidgetSerializer < ::BaseSerializer
      include ::Serializer::Sti

      def json_key
        'widget'
      end

      resolve_serializer_for_type_with do |type_name|
        "#{type_name.demodulize}Serializer".safe_constantize
      end
    end