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Mongoid implements many of the ActiveRecord callbacks.
Mongoid supports the following callbacks for documents:
Callbacks are available on any document, whether it is embedded within another document or not. Note that to be efficient, Mongoid only invokes the callback on the document that the persistence action was executed on. This enables Mongoid to support large hierarchies and to handle optimized atomic updates efficiently (without invoking callbacks throughout the document hierarchy).
Note that 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
Mongoid has a set of callbacks that are specific to associations - these are:
Each time a document is added or removed from any of the following
associations, the respective callbacks are invoked:
Association callbacks are specified as options on the respective association. The document added/removed will be passed as the parameter to the specified 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