Merge commit 'mainstream/master'

27 files changed, 317 insertions, 303 deletions

diff --git a/activerecord/lib/active_record.rb b/activerecord/lib/active_record.rb
index 68b0251982..2f1e7573d8 100644
--- a/activerecord/lib/active_record.rb
+++ b/activerecord/lib/active_record.rb
@@ -69,6 +69,7 @@ module ActiveRecord
   autoload :TestCase, 'active_record/test_case'
   autoload :Timestamp, 'active_record/timestamp'
   autoload :Transactions, 'active_record/transactions'
+  autoload :Validator, 'active_record/validator'
   autoload :Validations, 'active_record/validations'
 
   module AttributeMethods
diff --git a/activerecord/lib/active_record/associations.rb b/activerecord/lib/active_record/associations.rb
index 7f299b2aa5..f494e38e2f 100755
--- a/activerecord/lib/active_record/associations.rb
+++ b/activerecord/lib/active_record/associations.rb
@@ -42,11 +42,12 @@ module ActiveRecord
     end
   end
 
-  class HasManyThroughCantAssociateThroughHasManyReflection < ActiveRecordError #:nodoc:
+  class HasManyThroughCantAssociateThroughHasOneOrManyReflection < ActiveRecordError #:nodoc:
     def initialize(owner, reflection)
       super("Cannot modify association '#{owner.class.name}##{reflection.name}' because the source reflection class '#{reflection.source_reflection.class_name}' is associated to '#{reflection.through_reflection.class_name}' via :#{reflection.source_reflection.macro}.")
     end
   end
+
   class HasManyThroughCantAssociateNewRecords < ActiveRecordError #:nodoc:
     def initialize(owner, reflection)
       super("Cannot associate new records through '#{owner.class.name}##{reflection.name}' on '#{reflection.source_reflection.class_name rescue nil}##{reflection.source_reflection.name rescue nil}'. Both records must have an id in order to create the has_many :through record associating them.")
@@ -416,6 +417,32 @@ module ActiveRecord
     #   @firm.clients.collect { |c| c.invoices }.flatten # select all invoices for all clients of the firm
     #   @firm.invoices                                   # selects all invoices by going through the Client join model.
     #
+    # Similarly you can go through a +has_one+ association on the join model:
+    #
+    #   class Group < ActiveRecord::Base
+    #     has_many   :users
+    #     has_many   :avatars, :through => :users
+    #   end
+    #
+    #   class User < ActiveRecord::Base
+    #     belongs_to :group
+    #     has_one    :avatar
+    #   end
+    #
+    #   class Avatar < ActiveRecord::Base
+    #     belongs_to :user
+    #   end
+    #
+    #   @group = Group.first
+    #   @group.users.collect { |u| u.avatar }.flatten # select all avatars for all users in the group
+    #   @group.avatars                                # selects all avatars by going through the User join model.
+    #
+    # An important caveat with going through +has_one+ or +has_many+ associations on the join model is that these associations are 
+    # *read-only*.  For example, the following would not work following the previous example:
+    #
+    #   @group.avatars << Avatar.new                # this would work if User belonged_to Avatar rather than the other way around.
+    #   @group.avatars.delete(@group.avatars.last)  # so would this
+    #
     # === Polymorphic Associations
     #
     # Polymorphic associations on models are not restricted on what types of models they can be associated with.  Rather, they
@@ -819,7 +846,7 @@ module ActiveRecord
       # [:through]
       #   Specifies a Join Model through which to perform the query.  Options for <tt>:class_name</tt> and <tt>:foreign_key</tt>
       #   are ignored, as the association uses the source reflection. You can only use a <tt>:through</tt> query through a <tt>belongs_to</tt>
-      #   or <tt>has_many</tt> association on the join model.
+      #   <tt>has_one</tt> or <tt>has_many</tt> association on the join model.
       # [:source]
       #   Specifies the source association name used by <tt>has_many :through</tt> queries.  Only use it if the name cannot be
       #   inferred from the association.  <tt>has_many :subscribers, :through => :subscriptions</tt> will look for either <tt>:subscribers</tt> or
diff --git a/activerecord/lib/active_record/associations/association_collection.rb b/activerecord/lib/active_record/associations/association_collection.rb
index e67ccfb228..1b7bf42b91 100644
--- a/activerecord/lib/active_record/associations/association_collection.rb
+++ b/activerecord/lib/active_record/associations/association_collection.rb
@@ -208,6 +208,7 @@ module ActiveRecord
       # Note that this method will _always_ remove records from the database
       # ignoring the +:dependent+ option.
       def destroy(*records)
+        records = find(records) if records.any? {|record| record.kind_of?(Fixnum) || record.kind_of?(String)}
         remove_records(records) do |records, old_records|
           old_records.each { |record| record.destroy }
         end
diff --git a/activerecord/lib/active_record/associations/has_and_belongs_to_many_association.rb b/activerecord/lib/active_record/associations/has_and_belongs_to_many_association.rb
index fd23e59e82..d91c555dad 100644
--- a/activerecord/lib/active_record/associations/has_and_belongs_to_many_association.rb
+++ b/activerecord/lib/active_record/associations/has_and_belongs_to_many_association.rb
@@ -1,6 +1,11 @@
 module ActiveRecord
   module Associations
     class HasAndBelongsToManyAssociation < AssociationCollection #:nodoc:
+      def initialize(owner, reflection)
+        super
+        @primary_key_list = {}
+      end
+
       def create(attributes = {})
         create_record(attributes) { |record| insert_record(record) }
       end
@@ -17,6 +22,12 @@ module ActiveRecord
         @reflection.reset_column_information
       end
 
+      def has_primary_key?
+        return @has_primary_key unless @has_primary_key.nil?
+        @has_primary_key = (ActiveRecord::Base.connection.supports_primary_key? &&
+          ActiveRecord::Base.connection.primary_key(@reflection.options[:join_table]))
+      end
+
       protected
         def construct_find_options!(options)
           options[:joins]      = @join_sql
@@ -29,6 +40,11 @@ module ActiveRecord
         end
 
         def insert_record(record, force = true, validate = true)
+          if has_primary_key?
+            raise ActiveRecord::ConfigurationError,
+              "Primary key is not allowed in a has_and_belongs_to_many join table (#{@reflection.options[:join_table]})."
+          end
+
           if record.new_record?
             if force
               record.save!
diff --git a/activerecord/lib/active_record/associations/has_many_association.rb b/activerecord/lib/active_record/associations/has_many_association.rb
index e4b631bc54..73d3c23cd3 100644
--- a/activerecord/lib/active_record/associations/has_many_association.rb
+++ b/activerecord/lib/active_record/associations/has_many_association.rb
@@ -74,6 +74,7 @@ module ActiveRecord
                 "#{@reflection.primary_key_name} = NULL", 
                 "#{@reflection.primary_key_name} = #{owner_quoted_id} AND #{@reflection.klass.primary_key} IN (#{ids})"
               )
+              @owner.class.update_counters(@owner.id, cached_counter_attribute_name => -records.size) if has_cached_counter?
           end
         end
 
diff --git a/activerecord/lib/active_record/associations/has_many_through_association.rb b/activerecord/lib/active_record/associations/has_many_through_association.rb
index f4507c979c..829f0ac0c5 100644
--- a/activerecord/lib/active_record/associations/has_many_through_association.rb
+++ b/activerecord/lib/active_record/associations/has_many_through_association.rb
@@ -8,21 +8,11 @@ module ActiveRecord
       alias_method :new, :build
 
       def create!(attrs = nil)
-        ensure_owner_is_not_new
-
-        transaction do
-          self << (object = attrs ? @reflection.klass.send(:with_scope, :create => attrs) { @reflection.create_association! } : @reflection.create_association!)
-          object
-        end
+        create_record(attrs, true)
       end
 
       def create(attrs = nil)
-        ensure_owner_is_not_new
-
-        transaction do
-          self << (object = attrs ? @reflection.klass.send(:with_scope, :create => attrs) { @reflection.create_association } : @reflection.create_association)
-          object
-        end
+        create_record(attrs, false)
       end
 
       def destroy(*records)
@@ -40,8 +30,18 @@ module ActiveRecord
         return @target.size if loaded?
         return count
       end
-      
+
       protected
+        def create_record(attrs, force = true)
+          ensure_owner_is_not_new
+
+          transaction do
+            object = @reflection.klass.new(attrs)
+            add_record_to_target_with_callbacks(object) {|r| insert_record(object, force) }
+            object
+          end
+        end
+
         def target_reflection_has_associated_record?
           if @reflection.through_reflection.macro == :belongs_to && @owner[@reflection.through_reflection.primary_key_name].blank?
             false
@@ -65,9 +65,10 @@ module ActiveRecord
               return false unless record.save(validate)
             end
           end
-          through_reflection = @reflection.through_reflection
-          klass = through_reflection.klass
-          @owner.send(@reflection.through_reflection.name).proxy_target << klass.send(:with_scope, :create => construct_join_attributes(record)) { through_reflection.create_association! }
+
+          through_association = @owner.send(@reflection.through_reflection.name)
+          through_record = through_association.create!(construct_join_attributes(record))
+          through_association.proxy_target << through_record
         end
 
         # TODO - add dependent option support
diff --git a/activerecord/lib/active_record/associations/has_one_through_association.rb b/activerecord/lib/active_record/associations/has_one_through_association.rb
index 830aa1808a..a79bf943d1 100644
--- a/activerecord/lib/active_record/associations/has_one_through_association.rb
+++ b/activerecord/lib/active_record/associations/has_one_through_association.rb
@@ -18,9 +18,15 @@ module ActiveRecord
         current_object = @owner.send(@reflection.through_reflection.name)
 
         if current_object
-          new_value ? current_object.update_attributes(construct_join_attributes(new_value)) : current_object.destroy
-        else
-          @owner.send(@reflection.through_reflection.name,  klass.send(:create, construct_join_attributes(new_value))) if new_value
+           new_value ? current_object.update_attributes(construct_join_attributes(new_value)) : current_object.destroy
+        elsif new_value
+          if @owner.new_record?
+            self.target = new_value
+            through_association = @owner.send(:association_instance_get, @reflection.through_reflection.name)
+            through_association.build(construct_join_attributes(new_value))
+          else
+            @owner.send(@reflection.through_reflection.name, klass.create(construct_join_attributes(new_value)))
+          end
         end
       end
 
diff --git a/activerecord/lib/active_record/associations/through_association_scope.rb b/activerecord/lib/active_record/associations/through_association_scope.rb
index 8e7ce33814..16b6123439 100644
--- a/activerecord/lib/active_record/associations/through_association_scope.rb
+++ b/activerecord/lib/active_record/associations/through_association_scope.rb
@@ -93,7 +93,7 @@ module ActiveRecord
       # Construct attributes for :through pointing to owner and associate.
       def construct_join_attributes(associate)
         # TODO: revist this to allow it for deletion, supposing dependent option is supported
-        raise ActiveRecord::HasManyThroughCantAssociateThroughHasManyReflection.new(@owner, @reflection) if @reflection.source_reflection.macro == :has_many
+        raise ActiveRecord::HasManyThroughCantAssociateThroughHasOneOrManyReflection.new(@owner, @reflection) if [:has_one, :has_many].include?(@reflection.source_reflection.macro)
 
         join_attributes = construct_owner_attributes(@reflection.through_reflection).merge(@reflection.source_reflection.primary_key_name => associate.id)
 
diff --git a/activerecord/lib/active_record/attribute_methods/dirty.rb b/activerecord/lib/active_record/attribute_methods/dirty.rb
index 911c908c8b..4df0f1af69 100644
--- a/activerecord/lib/active_record/attribute_methods/dirty.rb
+++ b/activerecord/lib/active_record/attribute_methods/dirty.rb
@@ -1,95 +1,25 @@
+require 'active_support/core_ext/object/tap'
+
 module ActiveRecord
   module AttributeMethods
-    # Track unsaved attribute changes.
-    #
-    # A newly instantiated object is unchanged:
-    #   person = Person.find_by_name('Uncle Bob')
-    #   person.changed?       # => false
-    #
-    # Change the name:
-    #   person.name = 'Bob'
-    #   person.changed?       # => true
-    #   person.name_changed?  # => true
-    #   person.name_was       # => 'Uncle Bob'
-    #   person.name_change    # => ['Uncle Bob', 'Bob']
-    #   person.name = 'Bill'
-    #   person.name_change    # => ['Uncle Bob', 'Bill']
-    #
-    # Save the changes:
-    #   person.save
-    #   person.changed?       # => false
-    #   person.name_changed?  # => false
-    #
-    # Assigning the same value leaves the attribute unchanged:
-    #   person.name = 'Bill'
-    #   person.name_changed?  # => false
-    #   person.name_change    # => nil
-    #
-    # Which attributes have changed?
-    #   person.name = 'Bob'
-    #   person.changed        # => ['name']
-    #   person.changes        # => { 'name' => ['Bill', 'Bob'] }
-    #
-    # Resetting an attribute returns it to its original state:
-    #   person.reset_name!    # => 'Bill'
-    #   person.changed?       # => false
-    #   person.name_changed?  # => false
-    #   person.name           # => 'Bill'
-    #
-    # Before modifying an attribute in-place:
-    #   person.name_will_change!
-    #   person.name << 'y'
-    #   person.name_change    # => ['Bill', 'Billy']
     module Dirty
       extend ActiveSupport::Concern
-
-      DIRTY_AFFIXES = [
-        { :suffix => '_changed?' },
-        { :suffix => '_change' },
-        { :suffix => '_will_change!' },
-        { :suffix => '_was' },
-        { :prefix => 'reset_', :suffix => '!' }
-      ]
+      include ActiveModel::Dirty
 
       included do
-        attribute_method_affix *DIRTY_AFFIXES
-
-        alias_method_chain :save,            :dirty
-        alias_method_chain :save!,           :dirty
-        alias_method_chain :update,          :dirty
-        alias_method_chain :reload,          :dirty
+        alias_method_chain :save,   :dirty
+        alias_method_chain :save!,  :dirty
+        alias_method_chain :update, :dirty
+        alias_method_chain :reload, :dirty
 
         superclass_delegating_accessor :partial_updates
         self.partial_updates = true
       end
 
-      # Do any attributes have unsaved changes?
-      #   person.changed? # => false
-      #   person.name = 'bob'
-      #   person.changed? # => true
-      def changed?
-        !changed_attributes.empty?
-      end
-
-      # List of attributes with unsaved changes.
-      #   person.changed # => []
-      #   person.name = 'bob'
-      #   person.changed # => ['name']
-      def changed
-        changed_attributes.keys
-      end
-
-      # Map of changed attrs => [original value, new value].
-      #   person.changes # => {}
-      #   person.name = 'bob'
-      #   person.changes # => { 'name' => ['bill', 'bob'] }
-      def changes
-        changed.inject({}) { |h, attr| h[attr] = attribute_change(attr); h }
-      end
-
       # Attempts to +save+ the record and clears changed attributes if successful.
       def save_with_dirty(*args) #:nodoc:
         if status = save_without_dirty(*args)
+          @previously_changed = changes
           changed_attributes.clear
         end
         status
@@ -97,49 +27,21 @@ module ActiveRecord
 
       # Attempts to <tt>save!</tt> the record and clears changed attributes if successful.
       def save_with_dirty!(*args) #:nodoc:
-        status = save_without_dirty!(*args)
-        changed_attributes.clear
-        status
+        save_without_dirty!(*args).tap do
+          @previously_changed = changes 
+          changed_attributes.clear 
+        end
       end
 
       # <tt>reload</tt> the record and clears changed attributes.
       def reload_with_dirty(*args) #:nodoc:
-        record = reload_without_dirty(*args)
-        changed_attributes.clear
-        record
+        reload_without_dirty(*args).tap do
+          previously_changed_attributes.clear
+          changed_attributes.clear
+        end
       end
 
       private
-        # Map of change <tt>attr => original value</tt>.
-        def changed_attributes
-          @changed_attributes ||= {}
-        end
-
-        # Handle <tt>*_changed?</tt> for +method_missing+.
-        def attribute_changed?(attr)
-          changed_attributes.include?(attr)
-        end
-
-        # Handle <tt>*_change</tt> for +method_missing+.
-        def attribute_change(attr)
-          [changed_attributes[attr], __send__(attr)] if attribute_changed?(attr)
-        end
-
-        # Handle <tt>*_was</tt> for +method_missing+.
-        def attribute_was(attr)
-          attribute_changed?(attr) ? changed_attributes[attr] : __send__(attr)
-        end
-
-        # Handle <tt>reset_*!</tt> for +method_missing+.
-        def reset_attribute!(attr)
-          self[attr] = changed_attributes[attr] if attribute_changed?(attr)
-        end
-
-        # Handle <tt>*_will_change!</tt> for +method_missing+.
-        def attribute_will_change!(attr)
-          changed_attributes[attr] = clone_attribute_value(:read_attribute, attr)
-        end
-
         # Wrap write_attribute to remember original attribute value.
         def write_attribute(attr, value)
           attr = attr.to_s
@@ -182,23 +84,6 @@ module ActiveRecord
 
           old != value
         end
-
-      module ClassMethods
-        def self.extended(base)
-          class << base
-            alias_method_chain :alias_attribute, :dirty
-          end
-        end
-
-        def alias_attribute_with_dirty(new_name, old_name)
-          alias_attribute_without_dirty(new_name, old_name)
-          DIRTY_AFFIXES.each do |affixes|
-            module_eval <<-STR, __FILE__, __LINE__+1
-              def #{affixes[:prefix]}#{new_name}#{affixes[:suffix]}; self.#{affixes[:prefix]}#{old_name}#{affixes[:suffix]}; end  # def reset_subject!; self.reset_title!; end
-            STR
-          end
-        end
-      end
     end
   end
 end
diff --git a/activerecord/lib/active_record/base.rb b/activerecord/lib/active_record/base.rb
index 531a698f77..c5be561ea3 100755
--- a/activerecord/lib/active_record/base.rb
+++ b/activerecord/lib/active_record/base.rb
@@ -1394,7 +1394,7 @@ module ActiveRecord #:nodoc:
         end
         defaults << options[:default] if options[:default]
         defaults.flatten!
-        defaults << attribute_key_name.humanize
+        defaults << attribute_key_name.to_s.humanize
         options[:count] ||= 1
         I18n.translate(defaults.shift, options.merge(:default => defaults, :scope => [:activerecord, :attributes]))
       end
@@ -2294,20 +2294,24 @@ module ActiveRecord #:nodoc:
         # And for value objects on a composed_of relationship:
         #   { :address => Address.new("123 abc st.", "chicago") }
         #     # => "address_street='123 abc st.' and address_city='chicago'"
-        def sanitize_sql_hash_for_conditions(attrs, table_name = quoted_table_name)
+        def sanitize_sql_hash_for_conditions(attrs, default_table_name = quoted_table_name)
           attrs = expand_hash_conditions_for_aggregates(attrs)
 
           conditions = attrs.map do |attr, value|
+            table_name = default_table_name
+
             unless value.is_a?(Hash)
               attr = attr.to_s
 
               # Extract table name from qualified attribute names.
               if attr.include?('.')
-                table_name, attr = attr.split('.', 2)
-                table_name = connection.quote_table_name(table_name)
+                attr_table_name, attr = attr.split('.', 2)
+                attr_table_name = connection.quote_table_name(attr_table_name)
+              else
+                attr_table_name = table_name
               end
 
-              attribute_condition("#{table_name}.#{connection.quote_column_name(attr)}", value)
+              attribute_condition("#{attr_table_name}.#{connection.quote_column_name(attr)}", value)
             else
               sanitize_sql_hash_for_conditions(value, connection.quote_table_name(attr.to_s))
             end
@@ -3013,16 +3017,22 @@ module ActiveRecord #:nodoc:
 
       def execute_callstack_for_multiparameter_attributes(callstack)
         errors = []
-        callstack.each do |name, values|
+        callstack.each do |name, values_with_empty_parameters|
           begin
             klass = (self.class.reflect_on_aggregation(name.to_sym) || column_for_attribute(name)).klass
+            # in order to allow a date to be set without a year, we must keep the empty values.
+            # Otherwise, we wouldn't be able to distinguish it from a date with an empty day.
+            values = values_with_empty_parameters.reject(&:nil?)
+
             if values.empty?
               send(name + "=", nil)
             else
+
               value = if Time == klass
                 instantiate_time_object(name, values)
               elsif Date == klass
                 begin
+                  values = values_with_empty_parameters.collect do |v| v.nil? ? 1 : v end
                   Date.new(*values)
                 rescue ArgumentError => ex # if Date.new raises an exception on an invalid date
                   instantiate_time_object(name, values).to_date # we instantiate Time object and convert it back to a date thus using Time's logic in handling invalid dates
@@ -3050,10 +3060,8 @@ module ActiveRecord #:nodoc:
           attribute_name = multiparameter_name.split("(").first
           attributes[attribute_name] = [] unless attributes.include?(attribute_name)
 
-          unless value.empty?
-            attributes[attribute_name] <<
-              [ find_parameter_position(multiparameter_name), type_cast_attribute_value(multiparameter_name, value) ]
-          end
+          parameter_value = value.empty? ? nil : type_cast_attribute_value(multiparameter_name, value)
+          attributes[attribute_name] << [ find_parameter_position(multiparameter_name), parameter_value ]
         end
 
         attributes.each { |name, values| attributes[name] = values.sort_by{ |v| v.first }.collect { |v| v.last } }
diff --git a/activerecord/lib/active_record/calculations.rb b/activerecord/lib/active_record/calculations.rb
index 4a88c43dff..646fed1a0b 100644
--- a/activerecord/lib/active_record/calculations.rb
+++ b/activerecord/lib/active_record/calculations.rb
@@ -197,7 +197,7 @@ module ActiveRecord
           sql << ", #{options[:group_field]} AS #{options[:group_alias]}" if options[:group]
           if options[:from]
             sql << " FROM #{options[:from]} "
-          elsif scope && scope[:from]
+          elsif scope && scope[:from] && !use_workaround
             sql << " FROM #{scope[:from]} "
           else
             sql << " FROM (SELECT #{distinct}#{column_name}" if use_workaround
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
index f346e3ebc8..520f3c8c0c 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
@@ -315,6 +315,20 @@ module ActiveRecord
         @base = base
       end
 
+      #Handles non supported datatypes - e.g. XML
+      def method_missing(symbol, *args)
+        if symbol.to_s == 'xml'
+          xml_column_fallback(args)
+        end
+      end
+
+      def xml_column_fallback(*args)
+        case @base.adapter_name.downcase
+          when 'sqlite', 'mysql'
+            options = args.extract_options!
+            column(args[0], :text, options)
+          end
+        end
       # Appends a primary key definition to the table definition.
       # Can be called multiple times, but this is probably not a good idea.
       def primary_key(name)
@@ -705,3 +719,4 @@ module ActiveRecord
 
   end
 end
+
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
index 2473c772e3..20787ec510 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
@@ -107,7 +107,7 @@ module ActiveRecord
       # See also TableDefinition#column for details on how to create columns.
       def create_table(table_name, options = {})
         table_definition = TableDefinition.new(self)
-        table_definition.primary_key(options[:primary_key] || Base.get_primary_key(table_name)) unless options[:id] == false
+        table_definition.primary_key(options[:primary_key] || Base.get_primary_key(table_name.to_s.singularize)) unless options[:id] == false
 
         yield table_definition if block_given?
 
@@ -329,7 +329,7 @@ module ActiveRecord
             schema_migrations_table.column :version, :string, :null => false
           end
           add_index sm_table, :version, :unique => true,
-            :name => 'unique_schema_migrations'
+            :name => "#{Base.table_name_prefix}unique_schema_migrations#{Base.table_name_suffix}"
 
           # Backwards-compatibility: if we find schema_info, assume we've
           # migrated up to that point:
diff --git a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
index c533d4cdb6..fab70f34b9 100755
--- a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
@@ -56,6 +56,13 @@ module ActiveRecord
         false
       end
 
+      # Can this adapter determine the primary key for tables not attached
+      # to an ActiveRecord class, such as join tables?  Backend specific, as
+      # the abstract adapter always returns +false+.
+      def supports_primary_key?
+        false
+      end
+
       # Does this adapter support using DISTINCT within COUNT?  This is +true+
       # for all adapters except sqlite.
       def supports_count_distinct?
diff --git a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
index 2b882a1f25..4edb64c2c0 100644
--- a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
@@ -53,12 +53,7 @@ module ActiveRecord
       socket   = config[:socket]
       username = config[:username] ? config[:username].to_s : 'root'
       password = config[:password].to_s
-
-      if config.has_key?(:database)
-        database = config[:database]
-      else
-        raise ArgumentError, "No database specified. Missing argument: database."
-      end
+      database = config[:database]
 
       # Require the MySQL driver and define Mysql::Result.all_hashes
       unless defined? Mysql
@@ -81,7 +76,7 @@ module ActiveRecord
   module ConnectionAdapters
     class MysqlColumn < Column #:nodoc:
       def extract_default(default)
-        if type == :binary || type == :text
+        if sql_type =~ /blob/i || type == :text
           if default.blank?
             return null ? nil : ''
           else
@@ -95,7 +90,7 @@ module ActiveRecord
       end
 
       def has_default?
-        return false if type == :binary || type == :text #mysql forbids defaults on blob and text columns
+        return false if sql_type =~ /blob/i || type == :text #mysql forbids defaults on blob and text columns
         super
       end
 
@@ -213,6 +208,10 @@ module ActiveRecord
         true
       end
       
+      def supports_primary_key? #:nodoc:
+        true
+      end
+
       def supports_savepoints? #:nodoc:
         true
       end
@@ -555,6 +554,12 @@ module ActiveRecord
         keys.length == 1 ? [keys.first, nil] : nil
       end
 
+      # Returns just a table's primary key
+      def primary_key(table)
+        pk_and_sequence = pk_and_sequence_for(table)
+        pk_and_sequence && pk_and_sequence.first
+      end
+
       def case_sensitive_equality_operator
         "= BINARY"
       end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
index e77ae93c21..84cf1ad9fd 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
@@ -40,6 +40,12 @@ module ActiveRecord
   end
 
   module ConnectionAdapters
+    class TableDefinition
+      def xml(*args)
+        options = args.extract_options!
+        column(args[0], 'xml', options)
+      end
+    end
     # PostgreSQL-specific extensions to column definitions in a table.
     class PostgreSQLColumn < Column #:nodoc:
       # Instantiates a new PostgreSQL column definition in a table.
@@ -68,7 +74,7 @@ module ActiveRecord
           # depending on the server specifics
           super
         end
-  
+
         # Maps PostgreSQL-specific data types to logical Rails types.
         def simplified_type(field_type)
           case field_type
@@ -100,10 +106,10 @@ module ActiveRecord
               :string
             # XML type
             when /^xml$/
-              :string
+              :xml
             # Arrays
             when /^\D+\[\]$/
-              :string              
+              :string
             # Object identifier types
             when /^oid$/
               :integer
@@ -112,7 +118,7 @@ module ActiveRecord
               super
           end
         end
-  
+
         # Extracts the value from a PostgreSQL column default definition.
         def self.extract_value_from_default(default)
           case default
@@ -195,7 +201,8 @@ module ActiveRecord
         :time        => { :name => "time" },
         :date        => { :name => "date" },
         :binary      => { :name => "bytea" },
-        :boolean     => { :name => "boolean" }
+        :boolean     => { :name => "boolean" },
+        :xml         => { :name => "xml" }
       }
 
       # Returns 'PostgreSQL' as adapter name for identification purposes.
@@ -250,6 +257,11 @@ module ActiveRecord
         true
       end
 
+      # Does PostgreSQL support finding primary key on non-ActiveRecord tables?
+      def supports_primary_key? #:nodoc:
+        true
+      end
+
       # Does PostgreSQL support standard conforming strings?
       def supports_standard_conforming_strings?
         # Temporarily set the client message level above error to prevent unintentional
@@ -273,7 +285,7 @@ module ActiveRecord
       def supports_ddl_transactions?
         true
       end
-      
+
       def supports_savepoints?
         true
       end
@@ -365,7 +377,7 @@ module ActiveRecord
         if value.kind_of?(String) && column && column.type == :binary
           "#{quoted_string_prefix}'#{escape_bytea(value)}'"
         elsif value.kind_of?(String) && column && column.sql_type =~ /^xml$/
-          "xml '#{quote_string(value)}'"
+          "xml E'#{quote_string(value)}'"
         elsif value.kind_of?(Numeric) && column && column.sql_type =~ /^money$/
           # Not truly string input, so doesn't require (or allow) escape string syntax.
           "'#{value.to_s}'"
@@ -564,7 +576,7 @@ module ActiveRecord
       def rollback_db_transaction
         execute "ROLLBACK"
       end
-      
+
       if defined?(PGconn::PQTRANS_IDLE)
         # The ruby-pg driver supports inspecting the transaction status,
         # while the ruby-postgres driver does not.
@@ -811,6 +823,12 @@ module ActiveRecord
         nil
       end
 
+      # Returns just a table's primary key
+      def primary_key(table)
+        pk_and_sequence = pk_and_sequence_for(table)
+        pk_and_sequence && pk_and_sequence.first
+      end
+
       # Renames a table.
       def rename_table(name, new_name)
         execute "ALTER TABLE #{quote_table_name(name)} RENAME TO #{quote_table_name(new_name)}"
@@ -909,18 +927,18 @@ module ActiveRecord
         sql = "DISTINCT ON (#{columns}) #{columns}, "
         sql << order_columns * ', '
       end
-      
+
       # Returns an ORDER BY clause for the passed order option.
-      # 
+      #
       # PostgreSQL does not allow arbitrary ordering when using DISTINCT ON, so we work around this
       # by wrapping the +sql+ string as a sub-select and ordering in that query.
       def add_order_by_for_association_limiting!(sql, options) #:nodoc:
         return sql if options[:order].blank?
-        
+
         order = options[:order].split(',').collect { |s| s.strip }.reject(&:blank?)
         order.map! { |s| 'DESC' if s =~ /\bdesc$/i }
         order = order.zip((0...order.size).to_a).map { |s,i| "id_list.alias_#{i} #{s}" }.join(', ')
-        
+
         sql.replace "SELECT * FROM (#{sql}) AS id_list ORDER BY #{order}"
       end
 
@@ -1044,7 +1062,7 @@ module ActiveRecord
                 if res.ftype(cell_index) == MONEY_COLUMN_TYPE_OID
                   # Because money output is formatted according to the locale, there are two
                   # cases to consider (note the decimal separators):
-                  #  (1) $12,345,678.12        
+                  #  (1) $12,345,678.12
                   #  (2) $12.345.678,12
                   case column = row[cell_index]
                     when /^-?\D+[\d,]+\.\d{2}$/  # (1)
@@ -1104,3 +1122,4 @@ module ActiveRecord
     end
   end
 end
+
diff --git a/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb b/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
index 5eef692d05..d933bc924d 100644
--- a/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
@@ -24,11 +24,6 @@ module ActiveRecord
 
   module ConnectionAdapters #:nodoc:
     class SQLite3Adapter < SQLiteAdapter # :nodoc:
-      def table_structure(table_name)
-        structure = @connection.table_info(quote_table_name(table_name))
-        raise(ActiveRecord::StatementInvalid, "Could not find table '#{table_name}'") if structure.empty?
-        structure
-      end
     end
   end
 end
diff --git a/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb b/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb
index c0f5046bff..5ed7094169 100644
--- a/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb
@@ -4,27 +4,6 @@ require 'active_support/core_ext/kernel/requires'
 module ActiveRecord
   class Base
     class << self
-      # Establishes a connection to the database that's used by all Active Record objects
-      def sqlite_connection(config) # :nodoc:
-        parse_sqlite_config!(config)
-
-        unless self.class.const_defined?(:SQLite)
-          require_library_or_gem(config[:adapter])
-
-          db = SQLite::Database.new(config[:database], 0)
-          db.show_datatypes   = "ON" if !defined? SQLite::Version
-          db.results_as_hash  = true if defined? SQLite::Version
-          db.type_translation = false
-
-          # "Downgrade" deprecated sqlite API
-          if SQLite.const_defined?(:Version)
-            ConnectionAdapters::SQLite2Adapter.new(db, logger, config)
-          else
-            ConnectionAdapters::DeprecatedSQLiteAdapter.new(db, logger, config)
-          end
-        end
-      end
-
       private
         def parse_sqlite_config!(config)
           # Require database.
@@ -101,6 +80,10 @@ module ActiveRecord
         true
       end
 
+      def supports_primary_key? #:nodoc:
+        true
+      end
+
       def requires_reloading?
         true
       end
@@ -324,9 +307,9 @@ module ActiveRecord
         end
 
         def table_structure(table_name)
-          returning structure = execute("PRAGMA table_info(#{quote_table_name(table_name)})") do
-            raise(ActiveRecord::StatementInvalid, "Could not find table '#{table_name}'") if structure.empty?
-          end
+          structure = @connection.table_info(quote_table_name(table_name))
+          raise(ActiveRecord::StatementInvalid, "Could not find table '#{table_name}'") if structure.empty?
+          structure
         end
 
         def alter_table(table_name, options = {}) #:nodoc:
@@ -441,18 +424,5 @@ module ActiveRecord
         end
 
     end
-
-    class SQLite2Adapter < SQLiteAdapter # :nodoc:
-      def rename_table(name, new_name)
-        move_table(name, new_name)
-      end
-    end
-
-    class DeprecatedSQLiteAdapter < SQLite2Adapter # :nodoc:
-      def insert(sql, name = nil, pk = nil, id_value = nil)
-        execute(sql, name = nil)
-        id_value || @connection.last_insert_rowid
-      end
-    end
   end
 end
diff --git a/activerecord/lib/active_record/fixtures.rb b/activerecord/lib/active_record/fixtures.rb
index 6eeeddc9e1..99b812b5fc 100644
--- a/activerecord/lib/active_record/fixtures.rb
+++ b/activerecord/lib/active_record/fixtures.rb
@@ -622,7 +622,8 @@ class Fixtures < (RUBY_VERSION < '1.9' ? YAML::Omap : Hash)
               targets.each do |target|
                 join_fixtures["#{label}_#{target}"] = Fixture.new(
                   { association.primary_key_name => row[primary_key_name],
-                    association.association_foreign_key => Fixtures.identify(target) }, nil)
+                    association.association_foreign_key => Fixtures.identify(target) },
+                  nil, @connection)
               end
             end
           end
@@ -706,12 +707,12 @@ class Fixtures < (RUBY_VERSION < '1.9' ? YAML::Omap : Hash)
 
         yaml_value.each do |fixture|
           raise Fixture::FormatError, "Bad data for #{@class_name} fixture named #{fixture}" unless fixture.respond_to?(:each)
-	  fixture.each do |name, data|
+          fixture.each do |name, data|
             unless data
               raise Fixture::FormatError, "Bad data for #{@class_name} fixture named #{name} (nil)"
             end
 
-            self[name] = Fixture.new(data, model_class)
+            self[name] = Fixture.new(data, model_class, @connection)
           end
         end
       end
@@ -724,7 +725,7 @@ class Fixtures < (RUBY_VERSION < '1.9' ? YAML::Omap : Hash)
       reader.each do |row|
         data = {}
         row.each_with_index { |cell, j| data[header[j].to_s.strip] = cell.to_s.strip }
-        self["#{@class_name.to_s.underscore}_#{i+=1}"] = Fixture.new(data, model_class)
+        self["#{@class_name.to_s.underscore}_#{i+=1}"] = Fixture.new(data, model_class, @connection)
       end
     end
 
@@ -762,7 +763,8 @@ class Fixture #:nodoc:
 
   attr_reader :model_class
 
-  def initialize(fixture, model_class)
+  def initialize(fixture, model_class, connection = ActiveRecord::Base.connection)
+    @connection = connection
     @fixture = fixture
     @model_class = model_class.is_a?(Class) ? model_class : model_class.constantize rescue nil
   end
@@ -784,14 +786,14 @@ class Fixture #:nodoc:
   end
 
   def key_list
-    columns = @fixture.keys.collect{ |column_name| ActiveRecord::Base.connection.quote_column_name(column_name) }
+    columns = @fixture.keys.collect{ |column_name| @connection.quote_column_name(column_name) }
     columns.join(", ")
   end
 
   def value_list
     list = @fixture.inject([]) do |fixtures, (key, value)|
       col = model_class.columns_hash[key] if model_class.respond_to?(:ancestors) && model_class.ancestors.include?(ActiveRecord::Base)
-      fixtures << ActiveRecord::Base.connection.quote(value, col).gsub('[^\]\\n', "\n").gsub('[^\]\\r', "\r")
+      fixtures << @connection.quote(value, col).gsub('[^\]\\n', "\n").gsub('[^\]\\r', "\r")
     end
     list * ', '
   end
diff --git a/activerecord/lib/active_record/locale/en.yml b/activerecord/lib/active_record/locale/en.yml
index bf8a71d236..092f5f0023 100644
--- a/activerecord/lib/active_record/locale/en.yml
+++ b/activerecord/lib/active_record/locale/en.yml
@@ -23,6 +23,7 @@ en:
         less_than_or_equal_to: "must be less than or equal to {{count}}"
         odd: "must be odd"
         even: "must be even"
+        record_invalid: "Validation failed: {{errors}}"
         # Append your own errors here or at the model/attributes scope.
 
       # You can define own errors for models or model attributes.
diff --git a/activerecord/lib/active_record/reflection.rb b/activerecord/lib/active_record/reflection.rb
index 0baa9654b7..db5d2b25ed 100644
--- a/activerecord/lib/active_record/reflection.rb
+++ b/activerecord/lib/active_record/reflection.rb
@@ -314,7 +314,7 @@ module ActiveRecord
           raise HasManyThroughAssociationPolymorphicError.new(active_record.name, self, source_reflection)
         end
 
-        unless [:belongs_to, :has_many].include?(source_reflection.macro) && source_reflection.options[:through].nil?
+        unless [:belongs_to, :has_many, :has_one].include?(source_reflection.macro) && source_reflection.options[:through].nil?
           raise HasManyThroughSourceAssociationMacroError.new(self)
         end
 
diff --git a/activerecord/lib/active_record/serialization.rb b/activerecord/lib/active_record/serialization.rb
index 94f1e8f1fd..b49471f7ab 100644
--- a/activerecord/lib/active_record/serialization.rb
+++ b/activerecord/lib/active_record/serialization.rb
@@ -1,60 +1,58 @@
 module ActiveRecord #:nodoc:
   module Serialization
-    module RecordSerializer #:nodoc:
-      def initialize(*args)
-        super
-        options[:except] |= Array.wrap(@serializable.class.inheritance_column)
+    extend ActiveSupport::Concern
+    include ActiveModel::Serializers::JSON
+
+    def serializable_hash(options = nil)
+      options ||= {}
+
+      options[:except] = Array.wrap(options[:except]).map { |n| n.to_s }
+      options[:except] |= Array.wrap(self.class.inheritance_column)
+
+      hash = super(options)
+
+      serializable_add_includes(options) do |association, records, opts|
+        hash[association] = records.is_a?(Enumerable) ?
+          records.map { |r| r.serializable_hash(opts) } :
+          records.serializable_hash(opts)
       end
 
+      hash
+    end
+
+    private
       # Add associations specified via the <tt>:includes</tt> option.
       # Expects a block that takes as arguments:
       #   +association+ - name of the association
       #   +records+     - the association record(s) to be serialized
       #   +opts+        - options for the association records
-      def add_includes(&block)
-        if include_associations = options.delete(:include)
-          base_only_or_except = { :except => options[:except],
-                                  :only => options[:only] }
-
-          include_has_options = include_associations.is_a?(Hash)
-          associations = include_has_options ? include_associations.keys : Array.wrap(include_associations)
-
-          for association in associations
-            records = case @serializable.class.reflect_on_association(association).macro
-            when :has_many, :has_and_belongs_to_many
-              @serializable.send(association).to_a
-            when :has_one, :belongs_to
-              @serializable.send(association)
-            end
-
-            unless records.nil?
-              association_options = include_has_options ? include_associations[association] : base_only_or_except
-              opts = options.merge(association_options)
-              yield(association, records, opts)
-            end
-          end
+      def serializable_add_includes(options = {})
+        return unless include_associations = options.delete(:include)
 
-          options[:include] = include_associations
-        end
-      end
+        base_only_or_except = { :except => options[:except],
+                                :only => options[:only] }
+
+        include_has_options = include_associations.is_a?(Hash)
+        associations = include_has_options ? include_associations.keys : Array.wrap(include_associations)
 
-      def serializable_hash
-        hash = super
+        for association in associations
+          records = case self.class.reflect_on_association(association).macro
+          when :has_many, :has_and_belongs_to_many
+            send(association).to_a
+          when :has_one, :belongs_to
+            send(association)
+          end
 
-        add_includes do |association, records, opts|
-          hash[association] =
-            if records.is_a?(Enumerable)
-              records.collect { |r| self.class.new(r, opts).serializable_hash }
-            else
-              self.class.new(records, opts).serializable_hash
-            end
+          unless records.nil?
+            association_options = include_has_options ? include_associations[association] : base_only_or_except
+            opts = options.merge(association_options)
+            yield(association, records, opts)
+          end
         end
 
-        hash
+        options[:include] = include_associations
       end
-    end
   end
 end
 
 require 'active_record/serializers/xml_serializer'
-require 'active_record/serializers/json_serializer'
diff --git a/activerecord/lib/active_record/serializers/json_serializer.rb b/activerecord/lib/active_record/serializers/json_serializer.rb
deleted file mode 100644
index 63bf42c09d..0000000000
--- a/activerecord/lib/active_record/serializers/json_serializer.rb
+++ /dev/null
@@ -1,14 +0,0 @@
-module ActiveRecord #:nodoc:
-  module Serialization
-    extend ActiveSupport::Concern
-    include ActiveModel::Serializers::JSON
-
-    class JSONSerializer < ActiveModel::Serializers::JSON::Serializer
-      include Serialization::RecordSerializer
-    end
-
-    def encode_json(encoder)
-      JSONSerializer.new(self, encoder.options).to_s
-    end
-  end
-end
diff --git a/activerecord/lib/active_record/serializers/xml_serializer.rb b/activerecord/lib/active_record/serializers/xml_serializer.rb
index 4e172bd2b6..b19920741e 100644
--- a/activerecord/lib/active_record/serializers/xml_serializer.rb
+++ b/activerecord/lib/active_record/serializers/xml_serializer.rb
@@ -2,6 +2,8 @@ require 'active_support/core_ext/hash/conversions'
 
 module ActiveRecord #:nodoc:
   module Serialization
+    include ActiveModel::Serializers::Xml
+
     # Builds an XML document to represent the model. Some configuration is
     # available through +options+. However more complicated cases should
     # override ActiveRecord::Base#to_xml.
@@ -169,18 +171,15 @@ module ActiveRecord #:nodoc:
     #     end
     #   end
     def to_xml(options = {}, &block)
-      serializer = XmlSerializer.new(self, options)
-      block_given? ? serializer.to_s(&block) : serializer.to_s
-    end
-
-    def from_xml(xml)
-      self.attributes = Hash.from_xml(xml).values.first
-      self
+      XmlSerializer.new(self, options).serialize(&block)
     end
   end
 
   class XmlSerializer < ActiveModel::Serializers::Xml::Serializer #:nodoc:
-    include Serialization::RecordSerializer
+    def initialize(*args)
+      super
+      options[:except] |= Array.wrap(@serializable.class.inheritance_column)
+    end
 
     def serializable_attributes
       serializable_attribute_names.collect { |name| Attribute.new(name, @serializable) }
@@ -235,7 +234,9 @@ module ActiveRecord #:nodoc:
       builder.tag!(*args) do
         add_attributes
         procs = options.delete(:procs)
-        add_includes { |association, records, opts| add_associations(association, records, opts) }
+        @serializable.send(:serializable_add_includes, options) { |association, records, opts|
+          add_associations(association, records, opts)
+        }
         options[:procs] = procs
         add_procs
         yield builder if block_given?
diff --git a/activerecord/lib/active_record/validations.rb b/activerecord/lib/active_record/validations.rb
index a7fa98756e..5fc41cf054 100644
--- a/activerecord/lib/active_record/validations.rb
+++ b/activerecord/lib/active_record/validations.rb
@@ -12,7 +12,8 @@ module ActiveRecord
     attr_reader :record
     def initialize(record)
       @record = record
-      super("Validation failed: #{@record.errors.full_messages.join(", ")}")
+      errors = @record.errors.full_messages.join(I18n.t('support.array.words_connector', :default => ', '))
+      super(I18n.t('activerecord.errors.messages.record_invalid', :errors => errors))
     end
   end
 
diff --git a/activerecord/lib/active_record/validations/uniqueness.rb b/activerecord/lib/active_record/validations/uniqueness.rb
index edec4e9e43..711086dc2c 100644
--- a/activerecord/lib/active_record/validations/uniqueness.rb
+++ b/activerecord/lib/active_record/validations/uniqueness.rb
@@ -119,7 +119,7 @@ module ActiveRecord
             comparison_operator = "IS ?"
           elsif column.text?
             comparison_operator = "#{connection.case_sensitive_equality_operator} ?"
-            value = column.limit ? value.to_s[0, column.limit] : value.to_s
+            value = column.limit ? value.to_s.mb_chars[0, column.limit] : value.to_s
           else
             comparison_operator = "= ?"
           end
diff --git a/activerecord/lib/active_record/validator.rb b/activerecord/lib/active_record/validator.rb
new file mode 100644
index 0000000000..83a33f4dcd
--- /dev/null
+++ b/activerecord/lib/active_record/validator.rb
@@ -0,0 +1,68 @@
+module ActiveRecord #:nodoc:
+
+  # A simple base class that can be used along with ActiveRecord::Base.validates_with
+  #
+  #   class Person < ActiveRecord::Base
+  #     validates_with MyValidator
+  #   end
+  #
+  #   class MyValidator < ActiveRecord::Validator
+  #     def validate
+  #       if some_complex_logic
+  #         record.errors[:base] = "This record is invalid"
+  #       end
+  #     end
+  #
+  #     private
+  #       def some_complex_logic
+  #         # ...
+  #       end
+  #   end
+  #
+  # Any class that inherits from ActiveRecord::Validator will have access to <tt>record</tt>,
+  # which is an instance of the record being validated, and must implement a method called <tt>validate</tt>.
+  #
+  #   class Person < ActiveRecord::Base
+  #     validates_with MyValidator
+  #   end
+  #
+  #   class MyValidator < ActiveRecord::Validator
+  #     def validate
+  #       record # => The person instance being validated
+  #       options # => Any non-standard options passed to validates_with
+  #     end
+  #   end
+  #
+  # To cause a validation error, you must add to the <tt>record<tt>'s errors directly
+  # from within the validators message
+  #
+  #   class MyValidator < ActiveRecord::Validator
+  #     def validate
+  #       record.errors[:base] << "This is some custom error message"
+  #       record.errors[:first_name] << "This is some complex validation"
+  #       # etc...
+  #     end
+  #   end
+  #
+  # To add behavior to the initialize method, use the following signature:
+  #
+  #   class MyValidator < ActiveRecord::Validator
+  #     def initialize(record, options)
+  #       super
+  #       @my_custom_field = options[:field_name] || :first_name
+  #     end
+  #   end
+  #
+  class Validator
+    attr_reader :record, :options
+
+    def initialize(record, options)
+      @record = record
+      @options = options
+    end
+
+    def validate
+      raise "You must override this method"
+    end
+  end
+end