added touch option

README.md

@@ -146,6 +146,10 @@ class Thing < ActiveRecord::Base
     # integer column to specify order
     # position by default
     config[:position_column] = :position
+
+    # touch other members of relation on prepend
+    # true by default
+    config[:touch] = true
   end
 end
 ```

README.ru.md

@@ -146,6 +146,11 @@ class Thing < ActiveRecord::Base
     # используемое целочисленное поле в модели
     # по-умолчанию – position
     config[:position_column] = :position
+
+    # обновлять updated_at/updated_on для других экземпляров моделей
+    # внутри набора
+    # true по-умолчанию
+    config[:touch] = true
   end
 end
 ```

lib/activerecord/sortable/acts_as_sortable.rb

@@ -12,7 +12,8 @@ def acts_as_sortable(&block)
           options = {
             relation: ->(instance) { instance.class },
             append: false,
-            position_column: :position
+            position_column: :position,
+            touch: true
           }
           block.call(options) if block_given?
 
@@ -34,13 +35,15 @@ def sortable_relation_create_accessors
           cattr_accessor :sortable_append, instance_reader: true, instance_writer: false
           cattr_accessor :sortable_position_column, instance_reader: true, instance_writer: false
           cattr_accessor :escaped_sortable_position_column, instance_reader: true, instance_writer: false
+          cattr_accessor :sortable_touch, instance_reader: true, instance_writer: false
         end
 
         def sortable_relation_provide_accessor_values(options)
           self.sortable_relation = options[:relation]
           self.sortable_append = options[:append]
           self.sortable_position_column = options[:position_column]
           self.escaped_sortable_position_column = ActiveRecord::Base.connection.quote_column_name(options[:position_column])
+          self.sortable_touch = options[:touch]
         end
       end
     end

lib/activerecord/sortable/acts_as_sortable/instance_methods.rb

@@ -63,13 +63,18 @@ def sortable_updates_with_timestamps(base_query)
 
           query_items = [base_query]
 
-          update_values = timestamp_attributes_for_update_in_model.map do |attr|
+          update_values = sortable_timestamp_attributes_for_update_in_model.map do |attr|
             query_items << "#{attr} = ?"
             current_time
           end
           [query_items.join(', ')] + update_values
         end
 
+        def sortable_timestamp_attributes_for_update_in_model
+          return [] unless sortable_touch
+          timestamp_attributes_for_update_in_model
+        end
+
         def sortable_shift_on_destroy
           position_threshold = send(sortable_position_column)
           position_update = sortable_updates_with_timestamps("#{escaped_sortable_position_column} = #{escaped_sortable_position_column} - 1")

spec/spec_helper.rb

@@ -20,7 +20,6 @@
 Dir["#{File.dirname(__FILE__)}/support/**/*.rb"].each { |f| require f }
 
 RSpec.configure do |config|
-  config.treat_symbols_as_metadata_keys_with_true_values = true
   config.run_all_when_everything_filtered = true
   config.order = 'random'
 end

spec/support/activerecord_sortable.rb

@@ -37,8 +37,20 @@
         expect(subject.send(position_column)).to eq(0)
       end
 
-      it 'should change first thing updated_at' do
-        expect { subject }.to change { thing1.reload.updated_at }
+      context 'touch is on' do
+        it 'should change first thing updated_at' do
+          expect { subject }.to change { thing1.reload.updated_at }
+        end
+      end
+
+      context 'touch is off' do
+        before { described_class.sortable_touch = false }
+
+        it 'should not change first thing updated_at' do
+          expect { subject }.not_to change { thing1.reload.updated_at }
+        end
+
+        after { described_class.sortable_touch = true }
       end
     end
   end