zapo · August 29, 2015 13:58 · Apr 8, 2014 · Apr 8, 2014
diff --git a/dupable.rb b/dupable.rb
@@ -24,7 +24,7 @@ def duplicate
       end
 
       # copy all has_many through target by copying collection_ids... only needed to populate throught association targets and pass some children presence validations
-      # rails is too dump to inspect association models and deduce through association targets
+      # rails is too dumb to inspect association models and deduce through association targets
       #
       self.class.reflect_on_all_associations(:has_many).select { |a| a.through_reflection.present? }.each do |assoc|
         duplicate.send(:"#{assoc.name.to_s.singularize}_ids=", self.send(:"#{assoc.name.to_s.singularize.to_sym}_ids"))

diff --git a/dupable.rb b/dupable.rb
@@ -0,0 +1,42 @@
+module Concerns
+  module Dupable
+    def duplicate
+      # copy self with attributes only, includes belongs_to associations
+      duplicate = self.dup
+
+      # copy all has_many associations...
+      # reject through target associations, we only want to duplicate the association models
+
+      self.class.reflect_on_all_associations(:has_many).select { |a| a.through_reflection.nil? }.each do |assoc|
+        duplicate.send(:"#{assoc.name}=", self.send(assoc.name.to_sym).map { |item|
+          item = item.respond_to?(:duplicate) ? item.duplicate : item.dup
+
+          # delete foreign_key
+          item.send(:"#{assoc.foreign_key}=", nil)
+
+          # populate inverse assoc if present
+          if assoc.inverse_of.present?
+            item.send(:"#{assoc.inverse_of.name}=", duplicate)
+          end
+
+          item
+        })
+      end
+
+      # copy all has_many through target by copying collection_ids... only needed to populate throught association targets and pass some children presence validations
+      # rails is too dump to inspect association models and deduce through association targets
+      #
+      self.class.reflect_on_all_associations(:has_many).select { |a| a.through_reflection.present? }.each do |assoc|
+        duplicate.send(:"#{assoc.name.to_s.singularize}_ids=", self.send(:"#{assoc.name.to_s.singularize.to_sym}_ids"))
+      end
+
+      # copy all has_one associations
+      self.class.reflect_on_all_associations(:has_one).each do |assoc|
+        item = self.send(assoc.name.to_sym)
+        duplicate.send(:"#{assoc.name}=", item.respond_to?(:duplicate) ? item.duplicate : item.dup) if !item.nil?
+      end
+
+      duplicate
+    end
+  end
+end