Rails 2.1

Update to Rails 2.1 final.

vendor/rails/activemodel/lib/active_model/validations/confirmation.rb

@@ -0,0 +1,44 @@
+module ActiveModel
+  module Validations
+    module ClassMethods
+      # Encapsulates the pattern of wanting to validate a password or email address field with a confirmation. Example:
+      #
+      #   Model:
+      #     class Person < ActiveRecord::Base
+      #       validates_confirmation_of :user_name, :password
+      #       validates_confirmation_of :email_address, :message => "should match confirmation"
+      #     end
+      #
+      #   View:
+      #     <%= password_field "person", "password" %>
+      #     <%= password_field "person", "password_confirmation" %>
+      #
+      # The added +password_confirmation+ attribute is virtual; it exists only as an in-memory attribute for validating the password.
+      # To achieve this, the validation adds accessors to the model for the confirmation attribute. NOTE: This check is performed
+      # only if +password_confirmation+ is not +nil+, and by default only on save. To require confirmation, make sure to add a presence
+      # check for the confirmation attribute:
+      #
+      #   validates_presence_of :password_confirmation, :if => :password_changed?
+      #
+      # Configuration options:
+      # * <tt>:message</tt> - A custom error message (default is: "doesn't match confirmation")
+      # * <tt>:on</tt> - Specifies when this validation is active (default is <tt>:save</tt>, other options <tt>:create</tt>, <tt>:update</tt>)
+      # * <tt>:if</tt> - Specifies a method, proc or string to call to determine if the validation should
+      #   occur (e.g. <tt>:if => :allow_validation</tt>, or <tt>:if => Proc.new { |user| user.signup_step > 2 }</tt>).  The
+      #   method, proc or string should return or evaluate to a true or false value.
+      # * <tt>:unless</tt> - Specifies a method, proc or string to call to determine if the validation should
+      #   not occur (e.g. <tt>:unless => :skip_validation</tt>, or <tt>:unless => Proc.new { |user| user.signup_step <= 2 }</tt>).  The
+      #   method, proc or string should return or evaluate to a true or false value.
+      def validates_confirmation_of(*attr_names)
+        configuration = { :message => ActiveRecord::Errors.default_error_messages[:confirmation], :on => :save }
+        configuration.update(attr_names.extract_options!)
+
+        attr_accessor(*(attr_names.map { |n| "#{n}_confirmation" }))
+
+        validates_each(attr_names, configuration) do |record, attr_name, value|
+          record.errors.add(attr_name, configuration[:message]) unless record.send("#{attr_name}_confirmation").nil? or value == record.send("#{attr_name}_confirmation")
+        end
+      end
+    end
+  end
+end