Fix bug where PaperTrail was disabled in controller by default.

lib/paper_trail.rb

@@ -20,12 +20,14 @@ module PaperTrail
     !!PaperTrail.config.enabled
   end
 
-  # Returns `true` if PaperTrail is enabled for the controller, `false` otherwise.
+  # Returns `true` if PaperTrail is enabled for the request, `false` otherwise.
+  #
+  # See `PaperTrail::Controller#paper_trail_enabled_for_controller`.
   def self.enabled_for_controller?
     !!paper_trail_store[:request_enabled_for_controller]
   end
 
-  # Sets if PaperTrails is disabled by controller
+  # Sets whether PaperTrail is enabled or disabled for the current request.
   def self.enabled_for_controller=(value)
     paper_trail_store[:request_enabled_for_controller] = value
   end

lib/paper_trail/controller.rb

@@ -39,13 +39,20 @@ module PaperTrail
       {}
     end
 
+    # Returns `true` (default) or `false` depending on whether PaperTrail should
+    # be active for the current request.
+    #
+    # Override this method in your controller to specify when PaperTrail should
+    # be off.
+    def paper_trail_enabled_for_controller
+      true
+    end
+
     private
 
-    # Tells PaperTrail if version should be saved.
+    # Tells PaperTrail whether versions should be saved in the current request.
     def set_paper_trail_enabled_for_controller
-      if respond_to? :paper_trail_enabled_for_controller
-        ::PaperTrail.enabled_for_controller = paper_trail_enabled_for_controller
-      end
+      ::PaperTrail.enabled_for_controller = paper_trail_enabled_for_controller
     end
 
     # Tells PaperTrail who is responsible for any changes that occur.