ruby on rails - NameError when calling method in CanCan's Ability Class -

i'm using cancan role-based admin-system in application building. sort of template webshops, admin can have different role in each webshop he/she has access to. example: in webshop 1 moderator, , in webshop 2 editor.

so need in cancan's ability class check kind of role current user has in current shop (current_shop). wrote this:

class ability  include cancan::ability   def initialize(admin)     if admin.supervise?(current_shop, controller_gsub)      can :manage, :all    elsif admin.manage?(current_shop, controller_gsub)      can :manage, :all    elsif admin.access?(current_shop, controller_gsub)      can :read, :all    end   end end 

the problem can't seem call current_shop method ability class, because error:

undefined local variable or method `current_shop' #<ability:0x104df38b0> 

does know how go this? thanx in advance!

actually can't access of controller methods ability class. business logic? admin can manage every single thing if supervisor current_shop? or can manage things, manages shop?

then nice have smth like:

class ability  include cancan::ability   def initialize(admin)     can :manage, :all |obj|      admin.supervise?(obj.shop) || admin.manage?(obj.shop)    end    can :read, :all |obj|      admin.access?(obj.shop)    end   end end 

ps i'm not quite sure block work :all, , it's not quite logical call .shop on unknown class, that's show way, it's easy enough list models used