Alternative to has_many_polymorphs?

I've been trying to use the has_many_polymorphs plugin with rails 3 but I get this error that I have no idea how to resolve: https://stackoverflow.com/questions/5773379/how-do-i-patch-this-error-that-has-many-polymorphs-plugin-is-giving-me

I'm thinking of switching to some other solution to solve what I'm trying to do. I can probably use three different join tables with has_many through associations. 开发者_运维问答Are there any other alternative options I have for generating the functionality that the has_many_polymorphs plugin provides?

why you go for the plug-in it can be achieved by rails polymorphic associations see section 2.9 polymorphic associations on the given link Rails Associations

and i think there is no need for double sided polymorphism we can achieved it by simple polymorphic associations.