On has_many relations, there is a simple way to update all associated objects - just add touch: true and the updated_at field on all associated objects will get updated. This is a major issue with Russian Doll caching, because this is was expires the cache and makes sure the page shows the most recent changes. However has_and_belongs_to_many (HABTM) does not have a :touch option. It must be done manually. So, here's a quick and easy way to do this:
class Category before_save :touch_videos
def touch_videos videos.touch end end
class Video def self.touch update_all(updated_at: Time.now) # or, if you need validations to run for some reason find_each { |video| video.touch } end end
