Question

I am using Ruby on Rails 3.2.9 and I am just trying to use the state_machine gem. I have following statements:

class Article < ActiveRecord::Base
  state_machine :attribute => :status, :initial => :unconfirmed do
    state :confirmed, :value => 'confirmed'
    state :unconfirmed, :value => 'unconfirmed'

    event :confirm do
      transition :unconfirmed => :confirmed
    end

    event :unconfirm do
      transition :confirmed => :unconfirmed
    end
  end
end

I have also a confirmed_at attribute for the Article model intended to keep the last time when the :status switches to :confirmed.

How to initialize the confirmed_at attribute to the current time? How should I set the confirmed_at to the current time each time the :confirm event is triggered?

Answer 1

Looks like that’s what before_transition is for.

before_transition :confirmed => any - :confirmed, :do => :set_confirmed_at

Then add a method by that name:

def set_confirmed_at
  self.confirmed_at = Time.now
end