Added validates_exclusion_of as a negative of validates_inclusion_of

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@1236 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

3 files changed, 39 insertions, 0 deletions

diff --git a/activerecord/CHANGELOG b/activerecord/CHANGELOG
index 0194feb3fb..b9b470d30a 100644
--- a/activerecord/CHANGELOG
+++ b/activerecord/CHANGELOG
@@ -1,3 +1,10 @@
+*SVN*
+
+* Added validates_exclusion_of as a negative of validates_inclusion_of
+
+* Optimized counting of has_many associations by setting the association to empty if the count is 0 so repeated calls doesn't trigger database calls
+
+
 *1.10.1* (20th April, 2005)
 
 * Fixed frivilous database queries being triggered with eager loading on empty associations and other things
diff --git a/activerecord/lib/active_record/validations.rb b/activerecord/lib/active_record/validations.rb
index fb8879ef2a..9af4010a51 100755
--- a/activerecord/lib/active_record/validations.rb
+++ b/activerecord/lib/active_record/validations.rb
@@ -11,6 +11,7 @@ module ActiveRecord
     
     @@default_error_messages = {
       :inclusion => "is not included in the list",
+      :exclusion => "is reserved",
       :invalid => "is invalid",
       :confirmation => "doesn't match confirmation",
       :accepted  => "must be accepted",
@@ -470,6 +471,30 @@ module ActiveRecord
         end
       end
 
+      # Validates that the value of the specified attribute is not in a particular enumerable object.
+      #
+      #   class Person < ActiveRecord::Base
+      #     validates_exclusion_of :username, :in => %w( admin superuser ), :message => "You don't belong here"
+      #     validates_exclusion_of :age, :in => 30..60, :message => "This site is only for under 30 and over 60"
+      #   end
+      #
+      # Configuration options:
+      # * <tt>in</tt> - An enumerable object of items that the value shouldn't be part of
+      # * <tt>message</tt> - Specifies a customer error message (default is: "is reserved")
+      # * <tt>allow_nil</tt> - If set to true, skips this validation if the attribute is null (default is: false)
+      def validates_exclusion_of(*attr_names)
+        configuration = { :message => ActiveRecord::Errors.default_error_messages[:exclusion], :on => :save }
+        configuration.update(attr_names.pop) if attr_names.last.is_a?(Hash)
+
+        enum = configuration[:in] || configuration[:within]
+
+        raise(ArgumentError, "An object with the method include? is required must be supplied as the :in option of the configuration hash") unless enum.respond_to?("include?")
+
+        validates_each(attr_names, configuration) do |record, attr_name, value|
+          record.errors.add(attr_name, configuration[:message]) if enum.include?(value)
+        end
+      end
+
       # Validates whether the associated object or objects are all themselves valid. Works with any kind of association.
       #
       #   class Book < ActiveRecord::Base
diff --git a/activerecord/test/validations_test.rb b/activerecord/test/validations_test.rb
index 585cad39bd..89df29375c 100755
--- a/activerecord/test/validations_test.rb
+++ b/activerecord/test/validations_test.rb
@@ -303,6 +303,13 @@ class ValidationsTest < Test::Unit::TestCase
     assert Topic.create("title" => nil, "content" => "abc").valid?
   end
 
+  def test_validates_exclusion_of
+    Topic.validates_exclusion_of( :title, :in => %w( abe monkey ) )
+
+    assert Topic.create("title" => "something", "content" => "abc").valid?
+    assert !Topic.create("title" => "monkey", "content" => "abc").valid?
+  end
+
   def test_validates_length_of_using_minimum
     Topic.validates_length_of :title, :minimum => 5