Rails - Sep 2009 - Association problem

Hi, I''m new to ruby on rails. So i think i have association problems.

Given the three model classes with their associations:

# user.rb
class User < ActiveRecord::Base
  has_many :product_groups
  has_many :products, :through=>:product_groups
end

# product_group.rb
class ProductGroup < ActiveRecord::Base
  has_many :products
  belongs_to :user
end

# product.rb
class Product < ActiveRecord::Base
  belongs_to :product_group
  has_one :user
end

So when i trying add new product. I get errors.
# products_controller.rb
  def new
    @product = current_user.product_groups.products.build
  end
The error I''m receiving is:

   NoMethodError (undefined method `products'' for
#<Class:0x2ca50b0>):
     app/controllers/products_controller.rb:27:in `new''
     -e:2:in `load''
     -e:2

I''m confused, can anybody help me?

On Sep 15, 12:22 pm, Doloo
<zolzaya...-/E1597aS9LQAvxtiuMwx3w@public.gmane.org>
wrote:
> So when i trying add new product. I get errors.
> # products_controller.rb
>   def new
>     @product = current_user.product_groups.products.build
>   end
> The error I''m receiving is:
>
>    NoMethodError (undefined method `products'' for
#<Class:0x2ca50b0>):
>      app/controllers/products_controller.rb:27:in `new''
>      -e:2:in `load''
>      -e:2
A collection of product_groups doesn''t have a products method
(individual product group do).
Users have a products association, so why not do
current_user.products.build ? (Although I''m not sure if you can do a
has_many through where the join model has a has_many)

Fred

This is a example. I solve it. Thank you.

On Sep 15, 9:25 pm, Frederick Cheung
<frederick.che...-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
wrote:
> On Sep 15, 12:22 pm, Doloo
<zolzaya...-/E1597aS9LQAvxtiuMwx3w@public.gmane.org> wrote:
>
> > So when i trying add new product. I get errors.
> > # products_controller.rb
> >   def new
> >     @product = current_user.product_groups.products.build
> >   end
> > The error I''m receiving is:
>
> >    NoMethodError (undefined method `products'' for
#<Class:0x2ca50b0>):
> >      app/controllers/products_controller.rb:27:in `new''
> >      -e:2:in `load''
> >      -e:2
>
> A collection of product_groups doesn''t have a products method
> (individual product group do).
> Users have a products association, so why not do
> current_user.products.build ? (Although I''m not sure if you can do
a
> has_many through where the join model has a has_many)
>
> Fred