model add scope

app/models/product.rb

@@ -122,7 +122,7 @@ class Product < ActiveRecord::Base
             rate = (( self.price.to_f - self.buy_price.to_f )/self.buy_price.to_f)*100
         end 
             #return ((rate*100).round.to_f/100).to_s + "%"
-        return @admin_user.email
+            # return @admin_user.email
     end
 
     rails_admin do 
@@ -159,8 +159,13 @@ class Product < ActiveRecord::Base
             end
             #field :robo_balance_price
             field :user_sale_price
-            #field :buy_price
-            field :gross_interest_rate
+            field :buy_price do
+                visible true
+                formatted_value do
+                    bindings[:view].current_admin_user.email
+                 end
+            end
+            #field :gross_interest_rate
             field :count
             field :recommend
             field :status