validation macros can now be used within an instance

activemodel/lib/active_model/validations.rb

@@ -46,6 +46,9 @@ module ActiveModel
 
     included do
       extend ActiveModel::Translation
+
+      extend HelperMethods; include HelperMethods
+
       define_callbacks :validate, :scope => :name
 
       attr_accessor :validation_context
@@ -138,12 +141,6 @@ module ActiveModel
       def attribute_method?(attribute)
         method_defined?(attribute)
       end
-    private
-
-      def _merge_attributes(attr_names)
-        options = attr_names.extract_options!
-        options.merge(:attributes => attr_names.flatten)
-      end
     end
 
     # Returns the Errors object that holds all information about attribute error messages.

activemodel/lib/active_model/validations/acceptance.rb

@@ -21,7 +21,7 @@ module ActiveModel
       end
     end
 
-    module ClassMethods
+    module HelperMethods
       # Encapsulates the pattern of wanting to validate the acceptance of a terms of service check box (or similar agreement). Example:
       #
       #   class Person < ActiveRecord::Base

activemodel/lib/active_model/validations/confirmation.rb

@@ -12,7 +12,7 @@ module ActiveModel
       end
     end
 
-    module ClassMethods
+    module HelperMethods
       # Encapsulates the pattern of wanting to validate a password or email address field with a confirmation. Example:
       #
       #   Model:

activemodel/lib/active_model/validations/exclusion.rb

@@ -12,7 +12,7 @@ module ActiveModel
       end
     end
 
-    module ClassMethods
+    module HelperMethods
       # Validates that the value of the specified attribute is not in a particular enumerable object.
       #
       #   class Person < ActiveRecord::Base

activemodel/lib/active_model/validations/format.rb

@@ -24,7 +24,7 @@ module ActiveModel
       end
     end
 
-    module ClassMethods
+    module HelperMethods
       # Validates whether the value of the specified attribute is of the correct form, going by the regular expression provided.
       # You can require that the attribute matches the regular expression:
       #

activemodel/lib/active_model/validations/helper_methods.rb

@@ -0,0 +1,12 @@
+module ActiveModel
+  module Validations
+    module HelperMethods
+      private
+
+        def _merge_attributes(attr_names)
+          options = attr_names.extract_options!
+          options.merge(:attributes => attr_names.flatten)
+        end
+    end
+  end
+end

activemodel/lib/active_model/validations/inclusion.rb

@@ -12,7 +12,7 @@ module ActiveModel
       end
     end
 
-    module ClassMethods
+    module HelperMethods
       # Validates whether the value of the specified attribute is available in a particular enumerable object.
       #
       #   class Person < ActiveRecord::Base

activemodel/lib/active_model/validations/length.rb

@@ -51,7 +51,7 @@ module ActiveModel
       end
     end
 
-    module ClassMethods
+    module HelperMethods
 
       # Validates that the specified attribute matches the length restrictions supplied. Only one option can be used at a time:
       #

activemodel/lib/active_model/validations/numericality.rb

@@ -70,7 +70,7 @@ module ActiveModel
 
     end
 
-    module ClassMethods
+    module HelperMethods
       # Validates whether the value of the specified attribute is numeric by trying to convert it to
       # a float with Kernel.Float (if <tt>only_integer</tt> is false) or applying it to the regular expression
       # <tt>/\A[\+\-]?\d+\Z/</tt> (if <tt>only_integer</tt> is set to true).

activemodel/lib/active_model/validations/presence.rb

@@ -8,7 +8,7 @@ module ActiveModel
       end
     end
 
-    module ClassMethods
+    module HelperMethods
       # Validates that the specified attributes are not blank (as defined by Object#blank?). Happens by default on save. Example:
       #
       #   class Person < ActiveRecord::Base

activemodel/lib/active_model/validations/with.rb

@@ -75,5 +75,71 @@ module ActiveModel
         end
       end
     end
+
+    # Passes the record off to the class or classes specified and allows them
+    # to add errors based on more complex conditions.
+    #
+    #   class Person
+    #     include ActiveModel::Validations
+    #
+    #     validates :instance_validations
+    #
+    #     def instance_validations
+    #       validates_with MyValidator
+    #     end
+    #   end
+    #
+    #   class MyValidator < ActiveModel::Validator
+    #     def validate(record)
+    #       if some_complex_logic
+    #         record.errors[:base] << "This record is invalid"
+    #       end
+    #     end
+    #
+    #     private
+    #       def some_complex_logic
+    #         # ...
+    #       end
+    #   end
+    #
+    # You may also pass it multiple classes, like so:
+    #
+    #   class Person
+    #     include ActiveModel::Validations
+    #
+    #     validates :instance_validations, :on => :create
+    #
+    #     def instance_validations
+    #       validates_with MyValidator, MyOtherValidator
+    #     end
+    #   end
+    #
+    # Standard configuration options (:on, :if and :unless), which are
+    # available on the class version of validates_with, should instead be
+    # placed on the <tt>validates</tt> method as these are applied and tested
+    # in the callback
+    #
+    # If you pass any additional configuration options, they will be passed
+    # to the class and available as <tt>options</tt>:
+    #
+    #   class Person
+    #     include ActiveModel::Validations
+    #     validates_with MyValidator, :my_custom_key => "my custom value"
+    #   end
+    #
+    #   class MyValidator < ActiveModel::Validator
+    #     def validate(record)
+    #       options[:my_custom_key] # => "my custom value"
+    #     end
+    #   end
+    #
+    def validates_with(*args, &block)
+      options = args.extract_options!
+      args.each do |klass|
+        validator = klass.new(options, &block)
+        validator.setup(self) if validator.respond_to?(:setup)
+        validator.validate(self)
+      end
+    end
   end
 end

activemodel/test/cases/validations_test.rb

@@ -4,6 +4,7 @@ require 'cases/helper'
 require 'models/topic'
 require 'models/reply'
 require 'models/custom_reader'
+require 'models/automobile'
 
 class ValidationsTest < ActiveModel::TestCase
 
@@ -252,4 +253,16 @@ class ValidationsTest < ActiveModel::TestCase
     Topic.validates_length_of :title, :minimum => 10
     assert_equal 10, Topic.validators_on(:title).first.options[:minimum]
   end
+
+  def test_validations_on_the_instance_level
+    auto = Automobile.new
+
+    assert          auto.invalid?
+    assert_equal 2, auto.errors.size
+
+    auto.make  = 'Toyota'
+    auto.model = 'Corolla'
+
+    assert auto.valid?
+  end
 end

activemodel/test/models/automobile.rb

@@ -0,0 +1,12 @@
+class Automobile
+  include ActiveModel::Validations
+
+  validate :validations
+
+  attr_accessor :make, :model
+
+  def validations
+    validates_presence_of :make
+    validates_length_of   :model, :within => 2..10
+  end
+end