Extending a model in a component

Rails
1

I know I’m missing something basic, but I need help understanding
something:

I have a model (User) sitting in a component. I want to extend that
model from my app. I need to add in a has_many relationship and a
couple of methods.

I was able to mixin the methods using this:

module MyUser
def my_new_method
# etc
end
end

User.send(:include, MyUser::Acts::Chicken)

This just mixes in the new method. But if I add a ‘has_many’, I get
an error.

I’ve tried using the way to extend ActiveRecord (like in a plugin),
but that’s not working either.

module MyUser
def self.append_features(base)
super
base.extend(ClassMethods)
end

   module ClassMethods
     def my_new_method
     end
   end

end

User.send(:include, MyUser)

I’m not understanding the basics of extending a class, not just
mixing things in. Any pointers on this?

Thanks,
Brett