Rails: around_* callbacks

I have read the documentation at http://api.rubyonrails.org/classes/ActiveRecord/Callbacks.html, bu开发者_运维知识库t don't understand when the around_* callbacks are triggered in relation to before_* and after_*.

Any help much appreciated.

Thanks.

---

around_* callbacks are invoked before the action, then when you want to invoke the action itself, you yield to it, then continue execution. That's why it's called around

The order goes like this: before, around, after.

So, a typical around_save would look like this:

def around_save
   #do something...
   yield #saves
   #do something else...
end

---

The around_* callback is called around the action and inside the before_* and after_* actions. For example:

class User
  def before_save
    puts 'before save'
  end

  def after_save
    puts 'after_save'
  end

  def around_save
    puts 'in around save'
    yield # User saved
    puts 'out around save'
  end
end

User.save
  before save
  in around save
  out around save
  after_save
=> true