add mount_uploaders methods

lib/carrierwave/neo4j.rb

@@ -79,6 +79,72 @@ def _set_uploaders_nil
         end
         RUBY
       end
+
+      def mount_uploaders(column, uploader = nil, options = {}, &block)
+        super
+
+        serialize column, ::CarrierWave::Uploader::Base
+
+        include CarrierWave::Validations::ActiveModel
+
+        validates_integrity_of  column if uploader_option(column.to_sym, :validate_integrity)
+        validates_processing_of column if uploader_option(column.to_sym, :validate_processing)
+
+        after_save :"store_#{column}!"
+        before_save :"write_#{column}_identifier"
+        before_destroy :"clear_#{column}"
+        after_destroy :"remove_#{column}!"
+
+        class_eval <<-RUBY, __FILE__, __LINE__+1
+        def #{column}=(new_files)
+          column = _mounter(:#{column}).serialization_column
+          send(:attribute_will_change!, :#{column})
+          super
+        end
+
+        def remote_#{column}_urls=(url)
+          column = _mounter(:#{column}).serialization_column
+          send(:attribute_will_change!, :#{column})
+          super
+        end
+
+        def clear_#{column}
+          write_uploader(_mounter(:#{column}).serialization_column, nil)
+        end
+
+        def read_uploader(name)
+          send(:attribute, name.to_s)
+        end
+
+        def write_uploader(name, value)
+          send(:attribute=, name.to_s, value)
+        end
+
+        def reload_from_database
+          if reloaded = self.class.load_entity(neo_id)
+            send(:attributes=, reloaded.attributes.reject{ |k,v| v.is_a?(::CarrierWave::Uploader::Base) })
+          end
+          reloaded
+        end
+
+        # carrierwave keeps a instance variable of @uploaders, cached at init time
+        # but at init time, the value of the column is not yet available
+        # so after init, the empty @uploaders cache must be invalidated
+        # it will reinitialized with the processed column value on first access
+        unless method_defined?(:_set_uploaders_nil)
+
+          after_initialize :_set_uploaders_nil
+
+          def _set_uploaders_nil
+            if @_mounters
+              @_mounters.each do |_, mounter|
+                mounter.instance_variable_set(:@uploaders, nil)
+              end
+            end
+          end
+        end
+        RUBY
+      end
     end
 
   end

lib/carrierwave/neo4j/uploader_converter.rb

@@ -7,7 +7,11 @@ def convert_type
         end
 
         def to_db(value)
-          value.identifier
+          if value.is_a? Array
+            value.map(&:identifier)
+          else
+            value.identifier
+          end
         end
 
         def to_ruby(value)