Rails - May 2005 - creating callbacks

Does anyone have any sample code for creating custom callbacks for
observers?  I don''t believe there''s a callback that is called
when
adding or removing items in a has_and_belongs_to_many association. 
I''d like to kick off an email when this happens (to notify a bidder
that they''ve been outbid, for instance).  If you don''t have
some code
just laying around, I''ll take another stab at it later today perhaps.

Thanks

-- 
rick
http://techno-weenie.net

On Wednesday 01 June 2005 05:14, Rick Olson wrote:
> Does anyone have any sample code for creating custom callbacks for
> observers?  
I''ve written following small extension for AR::Base, to be able to 
notify observers by hand.

class ActiveRecord::Base

  def self.custom_notify(model, method)
    return unless model
    model.go_notify(method)
  end
  
  def go_notify(method)
    self.send(:notify, method)
    self
  end
  
end

I''m using it in one of my projects to track when user was authorized.

  def self.authenticate(login, pass)
    user = find_first(...)
    custom_notify(user, "authenticated")
  end  

#custom_notify is for use in class scope, and #go_notify is for 
instance scope.

I''m not sure about what''s the best way to connect this to
habtm
though.

HTH,
-- 
sdmitry -=- Dmitry V. Sabanin
http://sabanin.ru

On 6/2/05, Dmitry V. Sabanin <sdmitry-okj3p8EEQC8@public.gmane.org>
wrote:
> On Wednesday 01 June 2005 05:14, Rick Olson wrote:
> > Does anyone have any sample code for creating custom callbacks for
> > observers?
> I''ve written following small extension for AR::Base, to be able to
> notify observers by hand.
I went a different route with my own example.  Part of the reason I
did this is that my callback needed access to both models in a
has_and_belongs_to_many association.  I posted the code on Snippets: 
http://www.bigbold.com/snippets/posts/show/361

-- 
rick
http://techno-weenie.net