Overriding ActiveRecord associations for special cases

Hi,

Does anyone know a good way to override AR associations to take special cases into account. My current take is the example below which allows the 'root' user to access all products, but only works if I remember to call it with a .all/.find or similar method: 'user.products.all' instead of 'user.products'. Ideally I guess I want to return a proxy object that represents all products. Any ideas?

class User   has_many :products

  def root?     id == 1   end

  def products_with_root     if root?       Product # Better way?     else       products_without_root     end   end   alias_method_chain :products, :root end

Best regards, Andrew France

I think you have a design problem here. Access controll should be handled in the controller, not the model.

besides, having

def root?     id == 1   end

i believe is a very bad bad idea, maybe im wrong. any opinions anyone?

sorry, didint mention why it was a bad idea. Just in case the root user changes id. or someone can modify the parameters and pretend to be of id 1. and probably for som many reasons i forgot right now.

I think you have a design problem here. Access controll should be handled in the controller, not the model.

Thanks for replying. I don't know, I figure that the model is already deciding which users are associated with which products and expanding this to handle a special case is a logical extension that saves putting business logic in the controllers. Although I will probably have to revert to that as a fully-working solution.

besides, having

def root? id == 1 end

i believe is a very bad bad idea, maybe im wrong. any opinions anyone?

sorry, didint mention why it was a bad idea. Just in case the root user changes id. or someone can modify the parameters and pretend to be of id 1. and probably for som many reasons i forgot right now.

Not sure if these can be justified as since by the definition above if the root user changes their ID they are no longer the root user and if somebody can pretend to be other user IDs on a system I think it has bigger problems! Please let me know if you remember the other ones as security is of course important. Thanks.

Andrew

Not sure if these can be justified as since by the definition above if the root user changes their ID they are no longer the root user

and you would have NO root user in the system. If you have a system, where only root users can grant root access to other users you would have locked yourself out of your system.

Migrating to another db where there is already data or for some reason it decides not to assign an id of 1. then you find yourself in the same situation as before.

if you want to rely on a unique piece of info (that will not change with time, or migrations or other db situations) maybe name if it is unique or a boolean saying :admin => true

it is quite common in our projects that we put:

class User     DEV = ["wolas", "foo", "abr"]

   def developer?       DEV.include? name    end

   def admin?      developer? || super    end

end

respect to your original issue. i dont think that is business logic but mroe access control, which should be handled in the model. As in, root users can see all products but no other so:

def index   @proucts = if current_user.root?       Product.all    else       current_user.products    end end