From 0056e5aafb098ebece8616d786d7a6c1ec7a0288 Mon Sep 17 00:00:00 2001
From: Jay Pignata <john.pignata@gmail.com>
Date: Mon, 28 Sep 2009 00:40:54 -0400
Subject: [PATCH] Add options hash to memoize

This change will allow a :force option to be passed to memoize that will allow an already memoized method to be re-memoized. This is useful in scenarios such as inheritance where a method is overridden but cannot be memoized as its ancestor has left remnants of itself in the class
---
 activesupport/lib/active_support/memoizable.rb |   19 +++++++++++++------
 activesupport/test/memoizable_test.rb          |   13 +++++++++++++
 2 files changed, 26 insertions(+), 6 deletions(-)

diff --git a/activesupport/lib/active_support/memoizable.rb b/activesupport/lib/active_support/memoizable.rb
index b197fbc..4b8d993 100644
--- a/activesupport/lib/active_support/memoizable.rb
+++ b/activesupport/lib/active_support/memoizable.rb
@@ -19,7 +19,7 @@ module ActiveSupport
     def self.memoized_ivar_for(symbol)
       "@_memoized_#{symbol.to_s.sub(/\?\Z/, '_query').sub(/!\Z/, '_bang')}".to_sym
     end
-
+    
     module InstanceMethods
       def self.included(base)
         base.class_eval do
@@ -69,17 +69,24 @@ module ActiveSupport
       end
     end
 
-    def memoize(*symbols)
-      symbols.each do |symbol|
+    def memoize(*args)
+      options = args.pop if args.last.is_a? Hash
+      
+      args.each do |symbol|
         original_method = :"_unmemoized_#{symbol}"
         memoized_ivar = ActiveSupport::Memoizable.memoized_ivar_for(symbol)
 
+        unless options && options[:force]
+          class_eval <<-EOS, __FILE__, __LINE__ + 1
+            if method_defined?(:#{original_method})                                # if method_defined?(:_unmemoized_mime_type)
+              raise "Already memoized #{symbol}"                                   #   raise "Already memoized mime_type"
+            end                                                                    # end
+          EOS
+        end
+
         class_eval <<-EOS, __FILE__, __LINE__ + 1
           include InstanceMethods                                                  # include InstanceMethods
                                                                                    #
-          if method_defined?(:#{original_method})                                  # if method_defined?(:_unmemoized_mime_type)
-            raise "Already memoized #{symbol}"                                     #   raise "Already memoized mime_type"
-          end                                                                      # end
           alias #{original_method} #{symbol}                                       # alias _unmemoized_mime_type mime_type
                                                                                    #
           if instance_method(:#{symbol}).arity == 0                                # if instance_method(:mime_type).arity == 0
diff --git a/activesupport/test/memoizable_test.rb b/activesupport/test/memoizable_test.rb
index 195e3ea..0e8d686 100644
--- a/activesupport/test/memoizable_test.rb
+++ b/activesupport/test/memoizable_test.rb
@@ -44,6 +44,12 @@ class MemoizableTest < ActiveSupport::TestCase
     end
     memoize :is_developer?
   end
+  
+  class Employee < Person
+    def name
+      "John"
+    end
+  end
 
   class Company
     attr_reader :name_calls
@@ -248,4 +254,11 @@ class MemoizableTest < ActiveSupport::TestCase
     assert_equal 1, person.is_developer_calls
   end
 
+  def test_overridden_method_memoization
+    employee = Employee.new
+    employee.extend ActiveSupport::Memoizable
+    assert_nothing_raised { employee.memoize :name, :force => true }
+    assert_equal "John", employee.name
+  end
+
 end
-- 
1.6.4.2