_build_update_expression

in lib/aws-record/record/item_operations.rb [565:601]

• 35 lines of code
• 5 McCabe index (conditional complexity)

        def _build_update_expression(attr_value_pairs)
          set_expressions = []
          remove_expressions = []
          exp_attr_names = {}
          exp_attr_values = {}
          name_sub_token = "UE_A"
          value_sub_token = "ue_a"
          attr_value_pairs.each do |attr_sym, value|
            name_sub = "#" + name_sub_token
            value_sub = ":" + value_sub_token
            name_sub_token = name_sub_token.succ
            value_sub_token = value_sub_token.succ

            attribute = attributes.attribute_for(attr_sym)
            attr_name = attributes.storage_name_for(attr_sym)
            exp_attr_names[name_sub] = attr_name
            if _update_type_remove?(attribute, value)
              remove_expressions << "#{name_sub}"
            else
              set_expressions << "#{name_sub} = #{value_sub}"
              exp_attr_values[value_sub] = attribute.serialize(value)
            end
          end
          update_expressions = []
          unless set_expressions.empty?
            update_expressions << "SET " + set_expressions.join(", ")
          end
          unless remove_expressions.empty?
            update_expressions << "REMOVE " + remove_expressions.join(", ")
          end
          if update_expressions.empty?
            nil
          else
            [update_expressions.join(" "), exp_attr_names, exp_attr_values]
          end
        end