Contents

module Virtus
  class Attribute

    # Abstract superclass for collection Attributes.
    #
    # Handles coercing members to the designated member type.
    #
    # @abstract
    class Collection < Attribute
      default Proc.new { |_, attribute| attribute.type.primitive.new }

      # FIXME: temporary hack, remove when Axiom::Type works with EV as member_type
      Type = Struct.new(:primitive, :member_type) do
        def self.infer(type, primitive)
          return type if type.is_a?(Class) && type < Axiom::Types::Type

          klass  = Axiom::Types.infer(type)
          member = infer_member_type(type) || Object

          if EmbeddedValue.handles?(member)
            Type.new(primitive, member)
          else
            klass.new {
              primitive primitive
              member_type Axiom::Types.infer(member)
            }
          end
        end

        def self.infer_member_type(type)
          return unless type.respond_to?(:count)

          if type.count > 1
            raise NotImplementedError, "build SumType from list of types (#{type})"
          else
            type.first
          end
        end

        def coercion_method
          :to_array
        end
      end

      # @api private
      def self.build_type(options)
        Type.infer(options.fetch(:type), options.fetch(:primitive))
      end

      # @api private
      def self.merge_options!(type, options)
        unless options.key?(:member_type)
          options[:member_type] = Attribute.build(type.member_type)
        end
      end

      # @api public
      def coerce(*)
        super.each_with_object(primitive.new) do |entry, collection|
          collection << member_type.coerce(entry)
        end
      end

      def member_type
        @options[:member_type]
      end

    end # class Collection
  end # class Attribute
end # module Virtus

Version data entries

5 entries across 5 versions & 1 rubygems

Version	Path
virtus-1.0.0.beta7	lib/virtus/attribute/collection.rb
virtus-1.0.0.beta6	lib/virtus/attribute/collection.rb
virtus-1.0.0.beta5	lib/virtus/attribute/collection.rb
virtus-1.0.0.beta4	lib/virtus/attribute/collection.rb
virtus-1.0.0.beta3	lib/virtus/attribute/collection.rb