From a65f791fbd8cf16d17a963f32c7b85a5659c04e0 Mon Sep 17 00:00:00 2001
From: David Heinemeier Hansson <david@loudthinking.com>
Date: Thu, 9 Dec 2004 13:37:11 +0000
Subject: [PATCH] Added Base.validate_confirmation that encapsulates the
 pattern of wanting to validate a password or email address field with a
 confirmation.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@95 5ecf4fe2-1ee6-0310-87b1-e25e094e27de
---
 activerecord/CHANGELOG                        | 17 ++++++++++
 activerecord/lib/active_record/validations.rb | 31 +++++++++++++++++++
 activerecord/test/validations_test.rb         | 26 +++++++++++++---
 3 files changed, 70 insertions(+), 4 deletions(-)

diff --git a/activerecord/CHANGELOG b/activerecord/CHANGELOG
index 16ec1a1e14..7c12ad482e 100644
--- a/activerecord/CHANGELOG
+++ b/activerecord/CHANGELOG
@@ -1,5 +1,22 @@
 *CVS*
 
+* Added Base.validate_confirmation that encapsulates the pattern of wanting to validate a password or email address field with a confirmation. Example:
+ 
+     Model:
+       class Person < ActiveRecord::Base
+         validate_confirmation :password
+       end
+  
+     View:
+       <%= password_field "person", "password" %>
+       <%= password_field "person", "password_confirmation" %>
+  
+   The person has to already have a password attribute (a column in the people table), but the password_confirmation is virtual.
+   It exists only as an in-memory variable for validating the password.
+  
+   NOTE: This validation is only happening on create. When you want to update the record, you'll have to decide and pursue your
+   own course of action.
+
 * Added validation macros to make the stackable just like the lifecycle callbacks. Examples:
 
     class Person < ActiveRecord::Base
diff --git a/activerecord/lib/active_record/validations.rb b/activerecord/lib/active_record/validations.rb
index 14e79cf68b..25c43386fd 100755
--- a/activerecord/lib/active_record/validations.rb
+++ b/activerecord/lib/active_record/validations.rb
@@ -51,6 +51,37 @@ module ActiveRecord
 
         VALIDATIONS.each { |vd| base.class_eval("def self.#{vd}(*methods) write_inheritable_array(\"#{vd}\", methods - (read_inheritable_attribute(\"#{vd}\") || [])) end") }
       end
+      
+      base.extend(ClassMethods)
+    end
+
+    module ClassMethods
+      # Encapsulates the pattern of wanting to validate a password or email address field with a confirmation. Example:
+      #
+      #   Model:
+      #     class Person < ActiveRecord::Base
+      #       validate_confirmation :password
+      #     end
+      #
+      #   View:
+      #     <%= password_field "person", "password" %>
+      #     <%= password_field "person", "password_confirmation" %>
+      #
+      # The person has to already have a password attribute (a column in the people table), but the password_confirmation is virtual.
+      # It exists only as an in-memory variable for validating the password.
+      #
+      # NOTE: This validation is only happening on create. When you want to update the record, you'll have to decide and pursue your
+      # own course of action.
+      def validate_confirmation(*attr_names)
+        for attr_name in attr_names
+          attr_accessor "#{attr_name}_confirmation"
+          class_eval <<-EOC
+            validate_on_create(Proc.new { |record|
+              record.errors.add("#{attr_name}", "doesn't match confirmation") unless record.#{attr_name} == record.#{attr_name}_confirmation
+            })
+EOC
+        end
+      end
     end
 
     # The validation process on save can be skipped by passing false. The regular Base#save method is
diff --git a/activerecord/test/validations_test.rb b/activerecord/test/validations_test.rb
index 27a9b21c7d..a6cdc0a706 100755
--- a/activerecord/test/validations_test.rb
+++ b/activerecord/test/validations_test.rb
@@ -5,10 +5,7 @@ require 'fixtures/developer'
 
 
 class ValidationsTest < Test::Unit::TestCase
-  def setup
-    @topic_fixtures = create_fixtures("topics")
-    @developers = create_fixtures("developers")
-  end
+  fixtures :topics, :developers
 
   def test_single_field_validation
     r = Reply.new
@@ -124,3 +121,24 @@ class ValidationsTest < Test::Unit::TestCase
     assert developer.save
   end
 end
+
+
+class MacroValidationsTest < Test::Unit::TestCase
+  fixtures :topics, :developers
+
+  def setup
+    Topic.validate_confirmation(:title)
+  end
+
+  def teardown
+    Topic.write_inheritable_attribute("validate_on_create", [])
+  end
+
+  def test_title_confirmation
+    t = Topic.create("title" => "We should be confirmed")
+    assert !t.save
+
+    t.title_confirmation = "We should be confirmed"
+    assert t.save
+  end
+end
\ No newline at end of file