Rails - Jul 2007 - unable to get "has_many :after_add" to work - need help

Can someone tell me what I''m doing wrong?  I''ve spent way too
much
time on this

--------------------------------------------------------------------------------------
class Picture < ActiveRecord::Base
  has_many    :ratings, :after_add => :increment_rating, :after_remove
=> :decrement_rating

  def increment_members(rating)
    self.rating += rating.amount
    save!
  end
end

--------------------------------------------------------------------------------------
class Rating < ActiveRecord::Base
  belongs_to :picture
end

--------------------------------------------------------------------------------------
class CreatePictures < ActiveRecord::Migration
  def self.up
    create_table :pictures do |t|
      t.column :title,            :string
      t.column :rating,           :float
    end
  end

  def self.down
    drop_table :pictures
  end
end

--------------------------------------------------------------------------------------
class CreateRatings < ActiveRecord::Migration
  def self.up
    create_table :ratings do |t|
      t.column :picture_id,       :integer
      t.column :amount,           :float
    end
  end

  def self.down
    drop_table :ratings
  end
end


--------------------------------------------------------------------------------------
script/console
p = Picture.create(:title => ''p02'')
Rating.create(:amount => 5, :picture => p)

--------------------------------------------------------------------------------------


--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en
-~----------~----~----~----~------~----~------~--~---

Try p.ratings.create(:amount => 5). Otherwise you''re not going to 
trigger the callback since the callback is defined in the Picture model.

A more reliable callback would be an after_create in the Rating model, 
like so:

class Rating < ActiveRecord::Base
  belongs_to :picture

  def after_create
    self.picture.update_attribute(:rating, self.picture.rating + 
self.amount)
  end

  def after_destroy
    self.picture.update_attribute(:rating, self.picture.rating - 
self.amount)
  end
end

This would trigger either through p.ratings.create(:amount => 5) or 
Rating.create(:amount => 5, :picture => p)

-matthew

-- 
Posted via http://www.ruby-forum.com/.

--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en
-~----------~----~----~----~------~----~------~--~---

p.ratings.create(:amount => 5) didn''t work either... any other
thoughts on how to make this work?

I did think about using after_create in the Rating model (and will end
up doing that if I can''t get this to work) but it makes more sense in
my head to have an :after_add in the Picture model.  Does :after_add
just not work or am I missing something?


--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en
-~----------~----~----~----~------~----~------~--~---

I think you were almost there the first try.

script/console
p = Picture.create(:title => ''p02'')
r = Rating.create(:amount => 5)
p.ratings << r

The after_add is only fired when using the << function to add the
object to the collection.

--nkryptic


On Jul 21, 2:25 am, vince
<stha...-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
wrote:
> p.ratings.create(:amount => 5) didn''t work either... any other
> thoughts on how to make this work?
>
> I did think about using after_create in the Rating model (and will end
> up doing that if I can''t get this to work) but it makes more sense
in
> my head to have an :after_add in the Picture model.  Does :after_add
> just not work or am I missing something?

--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en
-~----------~----~----~----~------~----~------~--~---