You are looking at the docs for v4.x. You can check out this page for Mongoid v3.x if you haven't upgraded yet.
Mongoid supports the following callbacks:
Callbacks are available on any document, whether it is embedded within another document or not. Note that to be efficient, Mongoid only fires the callback of the document that the persistence action was executed on. This is that Mongoid aims to support large hierarchies and to handle optimized atomic updates callbacks can't be firing all over the document hierarchy.
Using callbacks for domain logic is a bad design practice, and can lead to unexpected errors that are hard to debug when callbacks in the chain halt execution. It is our recommendation to only use them for cross-cutting concerns, like queueing up background jobs.
class Article include Mongoid::Document field :name, type: String field :body, type: String field :slug, type: String before_create :send_message after_save do |document| # Handle callback here. end protected def send_message # Message sending code here. end end
Callbacks are coming from Active Support, so you can use the new syntax as well:
class Article include Mongoid::Document field :name, type: String set_callback(:create, :before) do |document| # Message sending code here. end end
Relation CallbacksSince 3.1.0
Mongoid has a set of callbacks that are specific to collection based relations - these are:
Each time a document is added or removed from any of the following relations,
the respective callbacks are fired:
Relation Callbacks are specified as an option on the relation. The element added/removed is the parameter to the method you call via the callback. Example:
class Person include Mongoid::Document has_many :posts, after_add: :send_email_to_subscribers end def send_email_to_subscribers(post) Notifications.new_post(post).deliver end