Rails partial inheritance hack

I have a STI table and want to be able to render a collection using

render @collection 

with every elements of the collection using their own partial or, if they don't have one, the parent partial. You know, partial inheritance.

So I added to my parent model :

def to_partial_path
  self.class._to_partial_path
end

protected

# a little hack to get partial inheritance in views, check if the partial exist, if not
# return the parent's one. Provide class level cache, be sure to restart your app when
# adding/removing partials.
def self._to_partial_path
  @_to_partial_path ||= begin
    element = ActiveSupport::Inflector.underscore(ActiveSupport::Inflector.demodulize(self))
    collection = ActiveSupport::Inflector.tableize(self)
    if File.exists?(Rails.root.join('app', 'views', collection, "_#{element}.html.erb")) ||
    self.superclass == ActiveRecord::Base

      "#{collection}/#{element}"
    else
      self.superclass._to_partial_path
    end
  end
end

The original code is here.

This seems to work great so far but I want to have some opinions.

Should I have gone another way ?

Any gotcha I may find myself into using this ?

Any way to refactor this ?

edit: No problem whatsoever, it's working great for now. I'm looking for a way to achieve something similar with form (ie render form in new and edit views render the child _form partial if their is one, the parent one otherwise).