find

# File activerecord/lib/active_record/associations/association_collection.rb, line 42
      def find(*args)
        options = args.extract_options!

        # If using a custom finder_sql, scan the entire collection.
        if @reflection.options[:finder_sql]
          expects_array = args.first.kind_of?(Array)
          ids           = args.flatten.compact.uniq.map { |arg| arg.to_i }

          if ids.size == 1
            id = ids.first
            record = load_target.detect { |r| id == r.id }
            expects_array ? [ record ] : record
          else
            load_target.select { |r| ids.include?(r.id) }
          end
        else
          merge_options_from_reflection!(options)
          construct_find_options!(options)

          find_scope = construct_scope[:find].slice(:conditions, :order)

          with_scope(:find => find_scope) do
            relation = @reflection.klass.send(:construct_finder_arel, options, @reflection.klass.send(:current_scoped_methods))

            case args.first
            when :first, :last
              relation.send(args.first)
            when :all
              records = relation.all
              @reflection.options[:uniq] ? uniq(records) : records
            else
              relation.find(*args)
            end
          end
        end
      end