Chainable Options

index_service_options.rb

  class IndexService
    class IndexServiceOptions
      def date_range start_date, end_date
        new @host, @values.merge(date_range: [start_date, end_date])
      end

      def hide_removed hide_removed=true
        new @host, @values.merge hide_removed: hide_removed
      end

      def merge_items merge_items=true
        new @host, @values.merge merge_items: merge_items
      end

      def initialize host, values={}
        @host = host
        @values = values.slice(:date_range, :hide_removed, :merge_items)
      end

      def perform shopping_list_id, options={}
        @host.perform(shopping_list_id, @values.merge(options))
      end

      def new shopping_list_id, options={}
        @host.new(shopping_list_id, @values.merge(options))
      end

      def method_missing method, *args, &block
        if @host.respond_to? method
          return @host.send(method, *args, &block)
        else
          super
        end
      end
    end

    def self.options options={}
      IndexServiceOptions.new(self, options)
    end

    class << self
      delegate :date_range, :hide_removed, :merge_items, to: 'options'
    end
  end

  # EX: IndexService.date_range(start_date, end_date).hide_removed.perform(shopping_list.id, {})
  configured_index_service = IndexService.date_range(start_date, end_date).hide_removed(params[:hide_removed])
  configured_index_service.perform(shopping_list.id, staples_list: true)