Revert "KISS."

Simpler doesn't work here.

This reverts commit e144ce29c9.

lib/devise.rb

@@ -16,6 +16,26 @@ module Devise
   }.freeze
 
   TRUE_VALUES = [true, 1, '1', 't', 'T', 'true', 'TRUE'].freeze
+
+  MODEL_CONFIG = []
+
+  def self.model_config(klass, accessor, default=nil)
+    # Create Devise accessor
+    mattr_accessor accessor
+
+    # Set default value
+    send(:"#{accessor}=", default)
+
+    # Store configuration method
+    MODEL_CONFIG << accessor
+
+    # Set default value
+    klass.class_eval <<-METHOD
+      def #{accessor}
+        Devise.#{accessor}
+      end
+    METHOD
+  end
 end
 
 require 'devise/warden'

lib/devise/active_record.rb

@@ -47,6 +47,7 @@ module Devise
     #
     def devise(*modules)
       options  = modules.extract_options!
+      options.assert_valid_keys(:except, *Devise::MODEL_CONFIG)
 
       modules  = Devise::ALL                    if modules.include?(:all)
       modules -= Array(options.delete(:except)) if options.key?(:except)
@@ -57,8 +58,17 @@ module Devise
         include Devise::Models.const_get(m.to_s.classify)
       end
 
+      # Convert new keys to methods which overwrites Devise defaults
       options.each do |key, value|
-        self.send(:"#{key}=", value)
+        if value.is_a?(Proc)
+          define_method key, &value
+        else
+          class_eval <<-END_EVAL, __FILE__, __LINE__
+            def #{key}
+              #{value.inspect}
+            end
+          END_EVAL
+        end
       end
     end
 

lib/devise/models/authenticable.rb

@@ -24,14 +24,13 @@ module Devise
     #    User.find(1).valid_password?('password123')         # returns true/false
     #
     module Authenticable
+      Devise.model_config(self, :pepper)
+      Devise.model_config(self, :stretches, 10)
+
       def self.included(base)
         base.class_eval do
           extend ClassMethods
 
-          cattr_accessor :pepper, :stretches, :instance_writer => false
-          protected :pepper, :stretches
-          self.pepper, self.stretches = nil, 10
-
           attr_reader :password
           attr_accessor :password_confirmation
           attr_accessible :email, :password, :password_confirmation