Merge remote branch 'mainstream/master'

20 files changed, 456 insertions, 306 deletions

diff --git a/activemodel/lib/active_model.rb b/activemodel/lib/active_model.rb
index 505e16c195..f14016027c 100644
--- a/activemodel/lib/active_model.rb
+++ b/activemodel/lib/active_model.rb
@@ -21,34 +21,41 @@
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #++
 
-activesupport_path = "#{File.dirname(__FILE__)}/../../activesupport/lib"
-$:.unshift(activesupport_path) if File.directory?(activesupport_path)
+activesupport_path = File.expand_path('../../../activesupport/lib', __FILE__)
+$:.unshift(activesupport_path) if File.directory?(activesupport_path) && !$:.include?(activesupport_path)
 require 'active_support'
 
+
 module ActiveModel
-  autoload :AttributeMethods, 'active_model/attribute_methods'
-  autoload :Conversion, 'active_model/conversion'
-  autoload :DeprecatedErrorMethods, 'active_model/deprecated_error_methods'
-  autoload :Dirty, 'active_model/dirty'
-  autoload :Errors, 'active_model/errors'
-  autoload :Lint, 'active_model/lint'
+  extend ActiveSupport::Autoload
+
+  autoload :AttributeMethods
+  autoload :Callbacks
+  autoload :Conversion
+  autoload :DeprecatedErrorMethods
+  autoload :Dirty
+  autoload :Errors
+  autoload :Lint
   autoload :Name, 'active_model/naming'
-  autoload :Naming, 'active_model/naming'
+  autoload :Naming
   autoload :Observer, 'active_model/observing'
-  autoload :Observing, 'active_model/observing'
-  autoload :Serialization, 'active_model/serialization'
-  autoload :StateMachine, 'active_model/state_machine'
-  autoload :TestCase, 'active_model/test_case'
-  autoload :Translation, 'active_model/translation'
-  autoload :Validations, 'active_model/validations'
-  autoload :ValidationsRepairHelper, 'active_model/validations_repair_helper'
-  autoload :Validator, 'active_model/validator'
-  autoload :VERSION, 'active_model/version'
+  autoload :Observing
+  autoload :Serialization
+  autoload :StateMachine
+  autoload :Translation
+  autoload :Validations
+  autoload :Validator
+  autoload :EachValidator, 'active_model/validator'
+  autoload :BlockValidator, 'active_model/validator'
+  autoload :VERSION
 
   module Serializers
-    autoload :JSON, 'active_model/serializers/json'
-    autoload :Xml, 'active_model/serializers/xml'
+    extend ActiveSupport::Autoload
+
+    autoload :JSON
+    autoload :Xml
   end
 end
 
+require 'active_support/i18n'
 I18n.load_path << File.dirname(__FILE__) + '/active_model/locale/en.yml'
diff --git a/activemodel/lib/active_model/callbacks.rb b/activemodel/lib/active_model/callbacks.rb
new file mode 100644
index 0000000000..f66a1ddcaa
--- /dev/null
+++ b/activemodel/lib/active_model/callbacks.rb
@@ -0,0 +1,91 @@
+require 'active_support/callbacks'
+
+module ActiveModel
+  module Callbacks
+    def self.extended(base)
+      base.class_eval do
+        include ActiveSupport::Callbacks
+      end
+    end
+
+    # Define callbacks similar to ActiveRecord ones. It means:
+    #
+    # * The callback chain is aborted whenever the block given to
+    #   _run_callbacks returns false.
+    #
+    # * If a class is given to the fallback, it will search for
+    #   before_create, around_create and after_create methods.
+    #
+    # == Usage
+    #
+    # First you need to define which callbacks your model will have:
+    #
+    #   class MyModel
+    #     define_model_callbacks :create
+    #   end
+    #
+    # This will define three class methods: before_create, around_create,
+    # and after_create. They accept a symbol, a string, an object or a block.
+    #
+    # After you create a callback, you need to tell when they are executed.
+    # For example, you could do:
+    #
+    #   def create
+    #     _run_create_callbacks do
+    #       super
+    #     end
+    #   end
+    # 
+    # == Options
+    #
+    # define_model_callbacks accepts all options define_callbacks does, in
+    # case you want to overwrite a default. Besides that, it also accepts
+    # an :only option, where you can choose if you want all types (before,
+    # around or after) or just some:
+    #
+    #   define_model_callbacks :initializer, :only => :after
+    #
+    def define_model_callbacks(*callbacks)
+      options = callbacks.extract_options!
+      options = { :terminator => "result == false", :scope => [:kind, :name] }.merge(options)
+
+      types = Array(options.delete(:only))
+      types = [:before, :around, :after] if types.empty?
+
+      callbacks.each do |callback|
+        define_callbacks(callback, options)
+
+        types.each do |type|
+          send(:"_define_#{type}_model_callback", self, callback)
+        end
+      end
+    end
+
+    def _define_before_model_callback(klass, callback) #:nodoc:
+      klass.class_eval <<-CALLBACK, __FILE__, __LINE__
+        def self.before_#{callback}(*args, &block)
+          set_callback(:#{callback}, :before, *args, &block)
+        end
+      CALLBACK
+    end
+
+    def _define_around_model_callback(klass, callback) #:nodoc:
+      klass.class_eval <<-CALLBACK, __FILE__, __LINE__
+        def self.around_#{callback}(*args, &block)
+          set_callback(:#{callback}, :around, *args, &block)
+        end
+      CALLBACK
+    end
+
+    def _define_after_model_callback(klass, callback) #:nodoc:
+      klass.class_eval <<-CALLBACK, __FILE__, __LINE__
+        def self.after_#{callback}(*args, &block)
+          options = args.extract_options!
+          options[:prepend] = true
+          options[:if] = Array(options[:if]) << "!halted && value != false"
+          set_callback(:#{callback}, :after, *(args << options), &block)
+        end
+      CALLBACK
+    end
+  end
+end
\ No newline at end of file
diff --git a/activemodel/lib/active_model/errors.rb b/activemodel/lib/active_model/errors.rb
index e8bb62953d..abc084a74b 100644
--- a/activemodel/lib/active_model/errors.rb
+++ b/activemodel/lib/active_model/errors.rb
@@ -97,18 +97,19 @@ module ActiveModel
       full_messages = []
 
       each do |attribute, messages|
-        messages = Array.wrap(messages)
+        messages = Array(messages)
         next if messages.empty?
 
         if attribute == :base
           messages.each {|m| full_messages << m }
         else
-          attr_name = @base.class.human_attribute_name(attribute)
-          options = { :default => ' ', :scope => @base.class.i18n_scope }
-          prefix = attr_name + I18n.t(:"errors.format.separator", options)
+          attr_name = attribute.to_s.gsub('.', '_').humanize
+          attr_name = @base.class.human_attribute_name(attribute, :default => attr_name)
+          options = { :default => "{{attribute}} {{message}}", :attribute => attr_name,
+                      :scope => @base.class.i18n_scope }
 
           messages.each do |m|
-            full_messages <<  "#{prefix}#{m}"
+            full_messages << I18n.t(:"errors.format", options.merge(:message => m))
           end
         end
       end
diff --git a/activemodel/lib/active_model/lint.rb b/activemodel/lib/active_model/lint.rb
index 1c2347adbf..0be82aa180 100644
--- a/activemodel/lib/active_model/lint.rb
+++ b/activemodel/lib/active_model/lint.rb
@@ -41,6 +41,20 @@ module ActiveModel
         assert_boolean model.destroyed?, "destroyed?"
       end
 
+      # naming
+      # ------
+      #
+      # Model.model_name must returns a string with some convenience methods as
+      # :human and :partial_path. Check ActiveModel::Naming for more information.
+      #
+      def test_model_naming
+        assert model.class.respond_to?(:model_name), "The model should respond to model_name"
+        model_name = model.class.model_name
+        assert_kind_of String, model_name
+        assert_kind_of String, model_name.human
+        assert_kind_of String, model_name.partial_path
+      end
+
       # errors
       # ------
       #
diff --git a/activemodel/lib/active_model/locale/en.yml b/activemodel/lib/active_model/locale/en.yml
index 0c2cf9ea33..1cdb897f13 100644
--- a/activemodel/lib/active_model/locale/en.yml
+++ b/activemodel/lib/active_model/locale/en.yml
@@ -1,6 +1,9 @@
 en:
   activemodel:
     errors:
+      # model.errors.full_messages format.
+      format: "{{attribute}} {{message}}"
+
       # The values :model, :attribute and :value are always available for interpolation
       # The value :count is available when applicable. Can be used for pluralization.
       messages:
diff --git a/activemodel/lib/active_model/naming.rb b/activemodel/lib/active_model/naming.rb
index 675d62b9a6..4cd68a0c89 100644
--- a/activemodel/lib/active_model/naming.rb
+++ b/activemodel/lib/active_model/naming.rb
@@ -2,11 +2,11 @@ require 'active_support/inflector'
 
 module ActiveModel
   class Name < String
-    attr_reader :singular, :plural, :element, :collection, :partial_path, :human
+    attr_reader :singular, :plural, :element, :collection, :partial_path
     alias_method :cache_key, :collection
 
-    def initialize(klass, name)
-      super(name)
+    def initialize(klass)
+      super(klass.name)
       @klass = klass
       @singular = ActiveSupport::Inflector.underscore(self).tr('/', '_').freeze
       @plural = ActiveSupport::Inflector.pluralize(@singular).freeze
@@ -15,13 +15,31 @@ module ActiveModel
       @collection = ActiveSupport::Inflector.tableize(self).freeze
       @partial_path = "#{@collection}/#{@element}".freeze
     end
+
+    # Transform the model name into a more humane format, using I18n. By default,
+    # it will underscore then humanize the class name (BlogPost.model_name.human #=> "Blog post").
+    # Specify +options+ with additional translating options.
+    def human(options={})
+      return @human unless @klass.respond_to?(:lookup_ancestors) &&
+                           @klass.respond_to?(:i18n_scope)
+
+      defaults = @klass.lookup_ancestors.map do |klass|
+        klass.model_name.underscore.to_sym
+      end
+
+      defaults << options.delete(:default) if options[:default]
+      defaults << @human
+
+      options.reverse_merge! :scope => [@klass.i18n_scope, :models], :count => 1, :default => defaults
+      I18n.translate(defaults.shift, options)
+    end
   end
 
   module Naming
     # Returns an ActiveModel::Name object for module. It can be
     # used to retrieve all kinds of naming-related information.
     def model_name
-      @_model_name ||= ActiveModel::Name.new(self, name)
+      @_model_name ||= ActiveModel::Name.new(self)
     end
   end
 end
diff --git a/activemodel/lib/active_model/railtie.rb b/activemodel/lib/active_model/railtie.rb
new file mode 100644
index 0000000000..63ffe5db63
--- /dev/null
+++ b/activemodel/lib/active_model/railtie.rb
@@ -0,0 +1,2 @@
+require "active_model"
+require "rails"
\ No newline at end of file
diff --git a/activemodel/lib/active_model/translation.rb b/activemodel/lib/active_model/translation.rb
index 42ca463f82..e5ef1e6114 100644
--- a/activemodel/lib/active_model/translation.rb
+++ b/activemodel/lib/active_model/translation.rb
@@ -37,28 +37,8 @@ module ActiveModel
 
     # Model.human_name is deprecated. Use Model.model_name.human instead.
     def human_name(*args)
-      ActiveSupport::Deprecation.warn("human_name has been deprecated, please use model_name.human instead", caller[0,1])
+      ActiveSupport::Deprecation.warn("human_name has been deprecated, please use model_name.human instead", caller[0,5])
       model_name.human(*args)
     end
   end
-
-  class Name < String
-    # Transform the model name into a more humane format, using I18n. By default,
-    # it will underscore then humanize the class name (BlogPost.human_name #=> "Blog post").
-    # Specify +options+ with additional translating options.
-    def human(options={})
-      return @human unless @klass.respond_to?(:lookup_ancestors) &&
-                           @klass.respond_to?(:i18n_scope)
-
-      defaults = @klass.lookup_ancestors.map do |klass|
-        klass.model_name.underscore.to_sym
-      end
-
-      defaults << options.delete(:default) if options[:default]
-      defaults << @human
-
-      options.reverse_merge! :scope => [@klass.i18n_scope, :models], :count => 1, :default => defaults
-      I18n.translate(defaults.shift, options)
-    end
-  end
 end
diff --git a/activemodel/lib/active_model/validations.rb b/activemodel/lib/active_model/validations.rb
index 064ec98f3a..d5460a58bd 100644
--- a/activemodel/lib/active_model/validations.rb
+++ b/activemodel/lib/active_model/validations.rb
@@ -1,5 +1,6 @@
 require 'active_support/core_ext/array/extract_options'
 require 'active_support/core_ext/hash/keys'
+require 'active_model/errors'
 
 module ActiveModel
   module Validations
@@ -12,6 +13,29 @@ module ActiveModel
     end
 
     module ClassMethods
+      # Validates each attribute against a block.
+      #
+      #   class Person < ActiveRecord::Base
+      #     validates_each :first_name, :last_name do |record, attr, value|
+      #       record.errors.add attr, 'starts with z.' if value[0] == ?z
+      #     end
+      #   end
+      #
+      # Options:
+      # * <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+.
+      # * <tt>:allow_blank</tt> - Skip validation if attribute is blank.
+      # * <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_each(*attr_names, &block)
+        options = attr_names.extract_options!.symbolize_keys
+        validates_with BlockValidator, options.merge(:attributes => attr_names.flatten), &block
+      end
+
       # Adds a validation method or block to the class. This is useful when
       # overriding the +validate+ instance method becomes too unwieldly and
       # you're looking for more descriptive declaration of your validations.
@@ -39,39 +63,6 @@ module ActiveModel
       #   end
       #
       # This usage applies to +validate_on_create+ and +validate_on_update as well+.
-
-      # Validates each attribute against a block.
-      #
-      #   class Person < ActiveRecord::Base
-      #     validates_each :first_name, :last_name do |record, attr, value|
-      #       record.errors.add attr, 'starts with z.' if value[0] == ?z
-      #     end
-      #   end
-      #
-      # Options:
-      # * <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+.
-      # * <tt>:allow_blank</tt> - Skip validation if attribute is blank.
-      # * <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_each(*attrs)
-        options = attrs.extract_options!.symbolize_keys
-        attrs   = attrs.flatten
-
-        # Declare the validation.
-        validate options do |record|
-          attrs.each do |attr|
-            value = record.send(:read_attribute_for_validation, attr)
-            next if (value.nil? && options[:allow_nil]) || (value.blank? && options[:allow_blank])
-            yield record, attr, value
-          end
-        end
-      end
-
       def validate(*args, &block)
         options = args.last
         if options.is_a?(Hash) && options.key?(:on)
diff --git a/activemodel/lib/active_model/validations/acceptance.rb b/activemodel/lib/active_model/validations/acceptance.rb
index b65c9b933d..bd9463ed27 100644
--- a/activemodel/lib/active_model/validations/acceptance.rb
+++ b/activemodel/lib/active_model/validations/acceptance.rb
@@ -1,5 +1,17 @@
 module ActiveModel
   module Validations
+    class AcceptanceValidator < EachValidator
+      def initialize(options)
+        super(options.reverse_merge(:allow_nil => true, :accept => "1"))
+      end
+
+      def validate_each(record, attribute, value)
+        unless value == options[:accept]
+          record.errors.add(attribute, :accepted, :default => options[:message])
+        end
+      end
+    end
+
     module ClassMethods
       # Encapsulates the pattern of wanting to validate the acceptance of a terms of service check box (or similar agreement). Example:
       #
@@ -25,8 +37,7 @@ module ActiveModel
       #   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 = { :allow_nil => true, :accept => "1" }
-        configuration.update(attr_names.extract_options!)
+        options = attr_names.extract_options!
 
         db_cols = begin
           column_names
@@ -37,11 +48,7 @@ module ActiveModel
         names = attr_names.reject { |name| db_cols.include?(name.to_s) }
         attr_accessor(*names)
 
-        validates_each(attr_names,configuration) do |record, attr_name, value|
-          unless value == configuration[:accept]
-            record.errors.add(attr_name, :accepted, :default => configuration[:message])
-          end
-        end
+        validates_with AcceptanceValidator, options.merge(:attributes => attr_names)
       end
     end
   end
diff --git a/activemodel/lib/active_model/validations/confirmation.rb b/activemodel/lib/active_model/validations/confirmation.rb
index d414224dd2..b06effdceb 100644
--- a/activemodel/lib/active_model/validations/confirmation.rb
+++ b/activemodel/lib/active_model/validations/confirmation.rb
@@ -1,5 +1,13 @@
 module ActiveModel
   module Validations
+    class ConfirmationValidator < EachValidator
+      def validate_each(record, attribute, value)
+        confirmed = record.send(:"#{attribute}_confirmation")
+        return if confirmed.nil? || value == confirmed
+        record.errors.add(attribute, :confirmation, :default => options[:message])
+      end
+    end
+
     module ClassMethods
       # Encapsulates the pattern of wanting to validate a password or email address field with a confirmation. Example:
       #
@@ -30,15 +38,9 @@ module ActiveModel
       #   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 = attr_names.extract_options!
-
-        attr_accessor(*(attr_names.map { |n| "#{n}_confirmation" }))
-
-        validates_each(attr_names, configuration) do |record, attr_name, value|
-          unless record.send("#{attr_name}_confirmation").nil? or value == record.send("#{attr_name}_confirmation")
-            record.errors.add(attr_name, :confirmation, :default => configuration[:message])
-          end
-        end
+        options = attr_names.extract_options!
+        attr_accessor(*(attr_names.map { |n| :"#{n}_confirmation" }))
+        validates_with ConfirmationValidator, options.merge(:attributes => attr_names)
       end
     end
   end
diff --git a/activemodel/lib/active_model/validations/exclusion.rb b/activemodel/lib/active_model/validations/exclusion.rb
index 2cfdec97a5..f8759f253b 100644
--- a/activemodel/lib/active_model/validations/exclusion.rb
+++ b/activemodel/lib/active_model/validations/exclusion.rb
@@ -1,5 +1,17 @@
 module ActiveModel
   module Validations
+    class ExclusionValidator < EachValidator
+      def check_validity!
+        raise ArgumentError, "An object with the method include? is required must be supplied as the " <<
+                             ":in option of the configuration hash" unless options[:in].respond_to?(:include?)
+      end
+
+      def validate_each(record, attribute, value)
+        return unless options[:in].include?(value)
+        record.errors.add(attribute, :exclusion, :default => options[:message], :value => value)
+      end
+    end
+
     module ClassMethods
       # Validates that the value of the specified attribute is not in a particular enumerable object.
       #
@@ -21,17 +33,9 @@ module ActiveModel
       #   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_exclusion_of(*attr_names)
-        configuration = attr_names.extract_options!
-
-        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|
-          if enum.include?(value)
-            record.errors.add(attr_name, :exclusion, :default => configuration[:message], :value => value)
-          end
-        end
+        options = attr_names.extract_options!
+        options[:in] ||= options.delete(:within)
+        validates_with ExclusionValidator, options.merge(:attributes => attr_names)
       end
     end
   end
diff --git a/activemodel/lib/active_model/validations/format.rb b/activemodel/lib/active_model/validations/format.rb
index c670dafc7c..d5427c2b03 100644
--- a/activemodel/lib/active_model/validations/format.rb
+++ b/activemodel/lib/active_model/validations/format.rb
@@ -1,5 +1,15 @@
 module ActiveModel
   module Validations
+    class FormatValidator < EachValidator
+      def validate_each(record, attribute, value)
+        if options[:with] && value.to_s !~ options[:with]
+          record.errors.add(attribute, :invalid, :default => options[:message], :value => value)
+        elsif options[:without] && value.to_s =~ options[:without]
+          record.errors.add(attribute, :invalid, :default => options[:message], :value => value)
+        end
+      end
+    end
+
     module ClassMethods
       # 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:
@@ -33,29 +43,21 @@ module ActiveModel
       #   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_format_of(*attr_names)
-        configuration = attr_names.extract_options!
+        options = attr_names.extract_options!
 
-        unless configuration.include?(:with) ^ configuration.include?(:without)  # ^ == xor, or "exclusive or"
+        unless options.include?(:with) ^ options.include?(:without)  # ^ == xor, or "exclusive or"
           raise ArgumentError, "Either :with or :without must be supplied (but not both)"
         end
 
-        if configuration[:with] && !configuration[:with].is_a?(Regexp)
+        if options[:with] && !options[:with].is_a?(Regexp)
           raise ArgumentError, "A regular expression must be supplied as the :with option of the configuration hash"
         end
 
-        if configuration[:without] && !configuration[:without].is_a?(Regexp)
+        if options[:without] && !options[:without].is_a?(Regexp)
           raise ArgumentError, "A regular expression must be supplied as the :without option of the configuration hash"
         end
 
-        if configuration[:with]
-          validates_each(attr_names, configuration) do |record, attr_name, value|
-            record.errors.add(attr_name, :invalid, :default => configuration[:message], :value => value) if value.to_s !~ configuration[:with]
-          end
-        elsif configuration[:without]
-          validates_each(attr_names, configuration) do |record, attr_name, value|
-            record.errors.add(attr_name, :invalid, :default => configuration[:message], :value => value) if value.to_s =~ configuration[:without]
-          end
-        end
+        validates_with FormatValidator, options.merge(:attributes => attr_names)
       end
     end
   end
diff --git a/activemodel/lib/active_model/validations/inclusion.rb b/activemodel/lib/active_model/validations/inclusion.rb
index 0d7dc5cd64..a122e9e737 100644
--- a/activemodel/lib/active_model/validations/inclusion.rb
+++ b/activemodel/lib/active_model/validations/inclusion.rb
@@ -1,5 +1,17 @@
 module ActiveModel
   module Validations
+    class InclusionValidator < EachValidator
+      def check_validity!
+         raise ArgumentError, "An object with the method include? is required must be supplied as the " <<
+                              ":in option of the configuration hash" unless options[:in].respond_to?(:include?)
+       end
+
+      def validate_each(record, attribute, value)
+        return if options[:in].include?(value)
+        record.errors.add(attribute, :inclusion, :default => options[:message], :value => value)
+      end
+    end
+
     module ClassMethods
       # Validates whether the value of the specified attribute is available in a particular enumerable object.
       #
@@ -21,17 +33,9 @@ module ActiveModel
       #   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_inclusion_of(*attr_names)
-        configuration = attr_names.extract_options!
-
-        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|
-          unless enum.include?(value)
-            record.errors.add(attr_name, :inclusion, :default => configuration[:message], :value => value)
-          end
-        end
+        options = attr_names.extract_options!
+        options[:in] ||= options.delete(:within)
+        validates_with InclusionValidator, options.merge(:attributes => attr_names)
       end
     end
   end
diff --git a/activemodel/lib/active_model/validations/length.rb b/activemodel/lib/active_model/validations/length.rb
index 6227239c9b..5db2060fe5 100644
--- a/activemodel/lib/active_model/validations/length.rb
+++ b/activemodel/lib/active_model/validations/length.rb
@@ -1,7 +1,75 @@
 module ActiveModel
   module Validations
+    class LengthValidator < EachValidator
+      OPTIONS   = [ :is, :within, :in, :minimum, :maximum ].freeze
+      MESSAGES  = { :is => :wrong_length, :minimum => :too_short, :maximum => :too_long }.freeze
+      CHECKS    = { :is => :==, :minimum => :>=, :maximum => :<= }.freeze
+
+      DEFAULT_TOKENIZER = lambda { |value| value.split(//) }
+      attr_reader :type
+
+      def initialize(options)
+        @type = (OPTIONS & options.keys).first
+        super(options.reverse_merge(:tokenizer => DEFAULT_TOKENIZER))
+      end
+
+      def check_validity!
+        ensure_one_range_option!
+        ensure_argument_types!
+      end
+        
+      def validate_each(record, attribute, value)
+        checks = options.slice(:minimum, :maximum, :is)
+        value  = options[:tokenizer].call(value) if value.kind_of?(String)
+
+        if [:within, :in].include?(type)
+          range = options[type]
+          checks[:minimum], checks[:maximum] = range.begin, range.end
+          checks[:maximum] -= 1 if range.exclude_end?
+        end
+
+        checks.each do |key, check_value|
+          custom_message = options[:message] || options[MESSAGES[key]]
+          validity_check = CHECKS[key]
+
+          valid_value = if key == :maximum
+            value.nil? || value.size.send(validity_check, check_value)
+          else
+            value && value.size.send(validity_check, check_value)
+          end
+
+          record.errors.add(attribute, MESSAGES[key], :default => custom_message, :count => check_value) unless valid_value
+        end
+      end
+
+    protected
+
+      def ensure_one_range_option! #:nodoc:
+        range_options = OPTIONS & options.keys
+
+        case range_options.size
+        when 0
+          raise ArgumentError, 'Range unspecified. Specify the :within, :maximum, :minimum, or :is option.'
+        when 1
+          # Valid number of options; do nothing.
+        else
+          raise ArgumentError, 'Too many range options specified. Choose only one.'
+        end
+      end
+    
+      def ensure_argument_types! #:nodoc:
+        value = options[type]
+
+        case type
+        when :within, :in
+          raise ArgumentError, ":#{type} must be a Range" unless value.is_a?(Range)
+        when :is, :minimum, :maximum
+          raise ArgumentError, ":#{type} must be a nonnegative Integer" unless value.is_a?(Integer) && value >= 0
+        end
+      end
+    end
+
     module ClassMethods
-      ALL_RANGE_OPTIONS = [ :is, :within, :in, :minimum, :maximum ].freeze
 
       # Validates that the specified attribute matches the length restrictions supplied. Only one option can be used at a time:
       #
@@ -38,62 +106,9 @@ module ActiveModel
       # * <tt>:tokenizer</tt> - Specifies how to split up the attribute string. (e.g. <tt>:tokenizer => lambda {|str| str.scan(/\w+/)}</tt> to
       #   count words as in above example.)
       #   Defaults to <tt>lambda{ |value| value.split(//) }</tt> which counts individual characters.
-      def validates_length_of(*attrs)
-        # Merge given options with defaults.
-        options = { :tokenizer => lambda {|value| value.split(//)} }
-        options.update(attrs.extract_options!.symbolize_keys)
-
-        # Ensure that one and only one range option is specified.
-        range_options = ALL_RANGE_OPTIONS & options.keys
-        case range_options.size
-        when 0
-          raise ArgumentError, 'Range unspecified.  Specify the :within, :maximum, :minimum, or :is option.'
-        when 1
-          # Valid number of options; do nothing.
-        else
-          raise ArgumentError, 'Too many range options specified.  Choose only one.'
-        end
-
-        # Get range option and value.
-        option = range_options.first
-        option_value = options[range_options.first]
-        key = {:is => :wrong_length, :minimum => :too_short, :maximum => :too_long}[option]
-        custom_message = options[:message] || options[key]
-
-        case option
-        when :within, :in
-          raise ArgumentError, ":#{option} must be a Range" unless option_value.is_a?(Range)
-
-          validates_each(attrs, options) do |record, attr, value|
-            value = options[:tokenizer].call(value) if value.kind_of?(String)
-
-            min, max = option_value.begin, option_value.end
-            max = max - 1 if option_value.exclude_end?
-
-            if value.nil? || value.size < min
-              record.errors.add(attr, :too_short, :default => custom_message || options[:too_short], :count => min)
-            elsif value.size > max
-              record.errors.add(attr, :too_long, :default => custom_message || options[:too_long], :count => max)
-            end
-          end
-        when :is, :minimum, :maximum
-          raise ArgumentError, ":#{option} must be a nonnegative Integer" unless option_value.is_a?(Integer) and option_value >= 0
-
-          # Declare different validations per option.
-          validity_checks = { :is => "==", :minimum => ">=", :maximum => "<=" }
-
-          validates_each(attrs, options) do |record, attr, value|
-            value = options[:tokenizer].call(value) if value.kind_of?(String)
-
-            valid_value = if option == :maximum
-              value.nil? || value.size.send(validity_checks[option], option_value)
-            else
-              value && value.size.send(validity_checks[option], option_value)
-            end
-
-            record.errors.add(attr, key, :default => custom_message, :count => option_value) unless valid_value
-          end
-        end
+      def validates_length_of(*attr_names)
+        options = attr_names.extract_options!
+        validates_with LengthValidator, options.merge(:attributes => attr_names)
       end
 
       alias_method :validates_size_of, :validates_length_of
diff --git a/activemodel/lib/active_model/validations/numericality.rb b/activemodel/lib/active_model/validations/numericality.rb
index 32dbcd82d0..f2aab8c5b8 100644
--- a/activemodel/lib/active_model/validations/numericality.rb
+++ b/activemodel/lib/active_model/validations/numericality.rb
@@ -1,10 +1,68 @@
 module ActiveModel
   module Validations
-    module ClassMethods
-      ALL_NUMERICALITY_CHECKS = { :greater_than => '>', :greater_than_or_equal_to => '>=',
-                                  :equal_to => '==', :less_than => '<', :less_than_or_equal_to => '<=',
-                                  :odd => 'odd?', :even => 'even?' }.freeze
+    class NumericalityValidator < EachValidator
+      CHECKS = { :greater_than => :>, :greater_than_or_equal_to => :>=,
+                 :equal_to => :==, :less_than => :<, :less_than_or_equal_to => :<=,
+                 :odd => :odd?, :even => :even? }.freeze
+
+      def initialize(options)
+        super(options.reverse_merge(:only_integer => false, :allow_nil => false))
+      end
+
+      def check_validity!
+        options.slice(*CHECKS.keys) do |option, value|
+          next if [:odd, :even].include?(option)
+          raise ArgumentError, ":#{option} must be a number, a symbol or a proc" unless value.is_a?(Numeric) || value.is_a?(Proc) || value.is_a?(Symbol)
+        end
+      end
+
+      def validate_each(record, attr_name, value)
+        before_type_cast = "#{attr_name}_before_type_cast"
+
+        raw_value = record.send("#{attr_name}_before_type_cast") if record.respond_to?(before_type_cast.to_sym)
+        raw_value ||= value
+
+        return if options[:allow_nil] && raw_value.nil?
+
+        unless value = parse_raw_value(raw_value, options)
+          record.errors.add(attr_name, :not_a_number, :value => raw_value, :default => options[:message])
+          return
+        end
+
+        options.slice(*CHECKS.keys).each do |option, option_value|
+          case option
+          when :odd, :even
+            unless value.to_i.send(CHECKS[option])
+              record.errors.add(attr_name, option, :value => value, :default => options[:message])
+            end
+          else
+            option_value = option_value.call(record) if option_value.is_a?(Proc)
+            option_value = record.send(option_value) if option_value.is_a?(Symbol)
+
+            unless value.send(CHECKS[option], option_value)
+              record.errors.add(attr_name, option, :default => options[:message], :value => value, :count => option_value)
+            end
+          end
+        end      
+      end
+
+    protected
+
+      def parse_raw_value(raw_value, options)
+        if options[:only_integer]
+          raw_value.to_i if raw_value.to_s =~ /\A[+-]?\d+\Z/
+        else
+          begin
+            Kernel.Float(raw_value)
+          rescue ArgumentError, TypeError
+            nil
+          end
+        end
+      end
 
+    end
+
+    module ClassMethods
       # 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).
@@ -44,61 +102,9 @@ module ActiveModel
       #     validates_numericality_of :width, :greater_than => :minimum_weight
       #   end
       #
-      #
-
       def validates_numericality_of(*attr_names)
-        configuration = { :only_integer => false, :allow_nil => false }
-        configuration.update(attr_names.extract_options!)
-
-        numericality_options = ALL_NUMERICALITY_CHECKS.keys & configuration.keys
-
-        (numericality_options - [ :odd, :even ]).each do |option|
-          value = configuration[option]
-          raise ArgumentError, ":#{option} must be a number, a symbol or a proc" unless value.is_a?(Numeric) || value.is_a?(Proc) || value.is_a?(Symbol)
-        end
-
-        validates_each(attr_names,configuration) do |record, attr_name, value|
-          before_type_cast = "#{attr_name}_before_type_cast"
-
-          if record.respond_to?(before_type_cast.to_sym)
-            raw_value = record.send("#{attr_name}_before_type_cast") || value
-          else
-            raw_value = value
-          end
-
-          next if configuration[:allow_nil] and raw_value.nil?
-
-          if configuration[:only_integer]
-            unless raw_value.to_s =~ /\A[+-]?\d+\Z/
-              record.errors.add(attr_name, :not_a_number, :value => raw_value, :default => configuration[:message])
-              next
-            end
-            raw_value = raw_value.to_i
-          else
-            begin
-              raw_value = Kernel.Float(raw_value)
-            rescue ArgumentError, TypeError
-              record.errors.add(attr_name, :not_a_number, :value => raw_value, :default => configuration[:message])
-              next
-            end
-          end
-
-          numericality_options.each do |option|
-            case option
-            when :odd, :even
-              unless raw_value.to_i.method(ALL_NUMERICALITY_CHECKS[option])[]
-                record.errors.add(attr_name, option, :value => raw_value, :default => configuration[:message])
-              end
-            else
-              configuration[option] = configuration[option].call(record)        if configuration[option].is_a? Proc
-              configuration[option] = record.method(configuration[option]).call if configuration[option].is_a? Symbol
-              
-              unless raw_value.method(ALL_NUMERICALITY_CHECKS[option])[configuration[option]]
-                record.errors.add(attr_name, option, :default => configuration[:message], :value => raw_value, :count => configuration[option])
-              end
-            end
-          end
-        end
+        options = attr_names.extract_options!
+        validates_with NumericalityValidator, options.merge(:attributes => attr_names)
       end
     end
   end
diff --git a/activemodel/lib/active_model/validations/presence.rb b/activemodel/lib/active_model/validations/presence.rb
index 3ff677c137..a4c6f866a7 100644
--- a/activemodel/lib/active_model/validations/presence.rb
+++ b/activemodel/lib/active_model/validations/presence.rb
@@ -2,6 +2,12 @@ require 'active_support/core_ext/object/blank'
 
 module ActiveModel
   module Validations
+    class PresenceValidator < EachValidator
+      def validate(record)
+        record.errors.add_on_blank(attributes, options[:message])
+      end
+    end
+
     module ClassMethods
       # Validates that the specified attributes are not blank (as defined by Object#blank?). Happens by default on save. Example:
       #
@@ -28,13 +34,8 @@ module ActiveModel
       #   The method, proc or string should return or evaluate to a true or false value.
       #
       def validates_presence_of(*attr_names)
-        configuration = attr_names.extract_options!
-
-        # can't use validates_each here, because it cannot cope with nonexistent attributes,
-        # while errors.add_on_empty can
-        validate configuration do |record|
-          record.errors.add_on_blank(attr_names, configuration[:message])
-        end
+        options = attr_names.extract_options!
+        validates_with PresenceValidator, options.merge(:attributes => attr_names)
       end
     end
   end
diff --git a/activemodel/lib/active_model/validations/with.rb b/activemodel/lib/active_model/validations/with.rb
index edc2133ddc..8d521173c6 100644
--- a/activemodel/lib/active_model/validations/with.rb
+++ b/activemodel/lib/active_model/validations/with.rb
@@ -48,14 +48,9 @@ module ActiveModel
       #     end
       #   end
       #
-      def validates_with(*args)
-        configuration = args.extract_options!
-
-        validate configuration do |record|
-          args.each do |klass|
-            klass.new(record, configuration.except(:on, :if, :unless)).validate
-          end
-        end
+      def validates_with(*args, &block)
+        options = args.extract_options!
+        args.each { |klass| validate(klass.new(options, &block), options) }
       end
     end
   end
diff --git a/activemodel/lib/active_model/validations_repair_helper.rb b/activemodel/lib/active_model/validations_repair_helper.rb
deleted file mode 100644
index 40741e6dbe..0000000000
--- a/activemodel/lib/active_model/validations_repair_helper.rb
+++ /dev/null
@@ -1,35 +0,0 @@
-module ActiveModel
-  module ValidationsRepairHelper
-    extend ActiveSupport::Concern
-
-    module ClassMethods
-      def repair_validations(*model_classes)
-        setup do
-          @_stored_callbacks = {}
-          model_classes.each do |k|
-            @_stored_callbacks[k] = k._validate_callbacks.dup
-          end
-        end
-        teardown do
-          model_classes.each do |k|
-            k._validate_callbacks = @_stored_callbacks[k]
-            k.__update_callbacks(:validate)
-          end
-        end
-      end
-    end
-
-    def repair_validations(*model_classes, &block)
-      @__stored_callbacks = {}
-      model_classes.each do |k|
-        @__stored_callbacks[k] = k._validate_callbacks.dup
-      end
-      return block.call
-    ensure
-      model_classes.each do |k|
-        k._validate_callbacks = @__stored_callbacks[k]
-        k.__update_callbacks(:validate)
-      end
-    end
-  end
-end
diff --git a/activemodel/lib/active_model/validator.rb b/activemodel/lib/active_model/validator.rb
index 09de72b757..01695cb73a 100644
--- a/activemodel/lib/active_model/validator.rb
+++ b/activemodel/lib/active_model/validator.rb
@@ -1,5 +1,4 @@
 module ActiveModel #:nodoc:
-
   # A simple base class that can be used along with ActiveModel::Base.validates_with
   #
   #   class Person < ActiveModel::Base
@@ -52,17 +51,60 @@ module ActiveModel #:nodoc:
   #       @my_custom_field = options[:field_name] || :first_name
   #     end
   #   end
-  #
   class Validator
-    attr_reader :record, :options
+    attr_reader :options
 
-    def initialize(record, options)
-      @record = record
+    def initialize(options)
       @options = options
     end
 
-    def validate
-      raise "You must override this method"
+    def validate(record)
+      raise NotImplementedError
+    end
+  end
+
+  # EachValidator is a validator which iterates through the attributes given
+  # in the options hash invoking the validate_each method passing in the
+  # record, attribute and value.
+  #
+  # All ActiveModel validations are built on top of this Validator.
+  class EachValidator < Validator
+    attr_reader :attributes
+
+    def initialize(options)
+      @attributes = Array(options.delete(:attributes))
+      raise ":attributes cannot be blank" if @attributes.empty?
+      super
+      check_validity!
+    end
+
+    def validate(record)
+      attributes.each do |attribute|
+        value = record.send(:read_attribute_for_validation, attribute)
+        next if (value.nil? && options[:allow_nil]) || (value.blank? && options[:allow_blank])
+        validate_each(record, attribute, value)
+      end
+    end
+
+    def validate_each(record, attribute, value)
+      raise NotImplementedError
+    end
+
+    def check_validity!
+    end
+  end
+
+  # BlockValidator is a special EachValidator which receives a block on initialization
+  # and call this block for each attribute being validated. +validates_each+ uses this
+  # Validator.
+  class BlockValidator < EachValidator
+    def initialize(options, &block)
+      @block = block
+      super
+    end
+
+    def validate_each(record, attribute, value)
+      @block.call(record, attribute, value)
     end
   end
 end