What are some examples of Active Record callbacks in Rails?

What are some examples of Active Record callbacks in Rails?

Active Record callbacks are methods that get called at certain points in an object's lifecycle. For example, before_save is called before an object is saved to the database.

Can you give me a specific example of using before_save?

Sure! You can use before_save to normalize a user's email before saving it. For instance:

class User < ApplicationRecord
  before_save :downcase_email

  private

  def downcase_email
    self.email = email.downcase
  end
end

What about after_create? How is that used?

after_create is called after a record is created. You might use it to send a welcome email to a user after they sign up. Here's an example:

class User < ApplicationRecord
  after_create :send_welcome_email

  private

  def send_welcome_email
    UserMailer.welcome_email(self).deliver_later
  end
end