Rails 2.1

Update to Rails 2.1 final.

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

@@ -0,0 +1,45 @@
+module ActiveModel
+  module Validations
+    module ClassMethods
+      # Encapsulates the pattern of wanting to validate the acceptance of a terms of service check box (or similar agreement). Example:
+      #
+      #   class Person < ActiveRecord::Base
+      #     validates_acceptance_of :terms_of_service
+      #     validates_acceptance_of :eula, :message => "must be abided"
+      #   end
+      #
+      # If the database column does not exist, the <tt>:terms_of_service</tt> attribute is entirely virtual. This check is
+      # performed only if <tt>:terms_of_service</tt> is not +nil+ and by default on save.
+      #
+      # Configuration options:
+      # * <tt>:message</tt> - A custom error message (default is: "must be accepted")
+      # * <tt>:on</tt> - Specifies when this validation is active (default is <tt>:save</tt>, other options <tt>:create</tt>, <tt>:update</tt>)
+      # * <tt>:allow_nil</tt> - Skip validation if attribute is +nil+. (default is +true+)
+      # * <tt>:accept</tt> - Specifies value that is considered accepted.  The default value is a string "1", which
+      #   makes it easy to relate to an HTML checkbox. This should be set to +true+ if you are validating a database
+      #   column, since the attribute is typecasted from "1" to +true+ before validation.
+      # * <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_acceptance_of(*attr_names)
+        configuration = { :message => ActiveRecord::Errors.default_error_messages[:accepted], :on => :save, :allow_nil => true, :accept => "1" }
+        configuration.update(attr_names.extract_options!)
+
+        db_cols = begin
+          column_names
+        rescue ActiveRecord::StatementInvalid
+          []
+        end
+        names = attr_names.reject { |name| db_cols.include?(name.to_s) }
+        attr_accessor(*names)
+
+        validates_each(attr_names,configuration) do |record, attr_name, value|
+          record.errors.add(attr_name, configuration[:message]) unless value == configuration[:accept]
+        end
+      end
+    end
+  end
+end