David Kimura PRO said almost 8 years ago on Fragment Caching :

You are absolutely correct. In the tutorials, I do like indicating self` as it is more clear where we are calling the methods from instead of a separate helper or extension outside of the model we're working with. For anyone who wants to see the available options for ActiveRecord::Dirty be sure to read up on them here http://api.rubyonrails.org/cla....