Fixes and simplifications for previous commit (to be squashed)

CHANGELOG.md

@@ -1,5 +1,7 @@
 # Pundit
 
+- Add autodetection of param key to `permitted_attributes` helper with ability to override it with `param_key` option.
+
 ## 1.0.1 (2015-05-27)
 
 - Fixed a regression where NotAuthorizedError could not be ininitialized with a string.

lib/pundit.rb

@@ -141,10 +141,10 @@ module Pundit
 
   def permitted_attributes(record, options={})
     name = options.delete(:param_key)
-    name ||= if record.class.respond_to?(:model_name) # ActiveModel and ActiveRecord
-               record.class.model_name.param_key
-             elsif record.respond_to?(:model_name)
+    name ||= if record.respond_to?(:model_name) # ActiveModel and ActiveRecord
                record.model_name.param_key
+             elsif record.is_a?(Class)
+               record.to_s.demodulize.underscore
              else
                record.class.to_s.demodulize.underscore
              end

spec/spec_helper.rb

@@ -58,7 +58,8 @@ end
 
 module Customer
   class Post < Post
-    def self.model_name
+    # In ActiveRecord this method is accessible at both object and class level
+    def model_name
       OpenStruct.new(param_key: 'customer_post')
     end
     def policy_class