I have a lot of code in my project like the following:

class Animal < ActiveRecord::Base
  state_machine do
    around_transition :on => :sure do |animal, _, block|
      animal.transaction do
        block.call
        animal.do_things_on_sure
      end
    end
  end
end

around_transition looks ugly and repeats for many classes.. Lets refactor it. More under the cut

State Machine comes to the rescue when models in your application need statuses and events.

There is a #state_machine gem for #ruby.

I recommend you to spend some time studying basics before you start using it with #rails. More under the cut

I wrote a #microgem for a simple validation a state of the object with #statemachine More under the cut