Callback for creation of nested model instance

Question

class Category < ActiveRecord::Base
  has_many    :posts
  accepts_nested_attributes_for :posts
end

Is it possible in the Category model to understand if there's a Post instance being created along with the saving of a Category instance?

Answer 1

You can query the posts collection from the category instance to see if any new records exist. If so they'll be saved when category is.

category.posts.any?(&:new_record?)