Add scoping and unscoped as the syntax to replace the old with_scope and with_exclusive_scope. A few examples:

* with_scope now should be scoping:

Before:

  Comment.with_scope(:find => { :conditions => { :post_id => 1 } }) do
    Comment.first #=> SELECT * FROM comments WHERE post_id = 1
  end

After:

  Comment.where(:post_id => 1).scoping do
    Comment.first #=> SELECT * FROM comments WHERE post_id = 1
  end

* with_exclusive_scope now should be unscoped:

  class Post < ActiveRecord::Base
    default_scope :published => true
  end

  Post.all #=> SELECT * FROM posts WHERE published = true

Before:

  Post.with_exclusive_scope do
    Post.all #=> SELECT * FROM posts
  end

After:

  Post.unscoped do
    Post.all #=> SELECT * FROM posts
  end

Notice you can also use unscoped without a block and it will return an anonymous scope with default_scope values:

  Post.unscoped.all #=> SELECT * FROM posts

5 files changed, 79 insertions, 44 deletions

diff --git a/activerecord/lib/active_record/base.rb b/activerecord/lib/active_record/base.rb
index 8c10f86486..c0ded7f558 100644
--- a/activerecord/lib/active_record/base.rb
+++ b/activerecord/lib/active_record/base.rb
@@ -398,7 +398,7 @@ module ActiveRecord #:nodoc:
 
       delegate :find, :first, :last, :all, :destroy, :destroy_all, :exists?, :delete, :delete_all, :update, :update_all, :to => :scoped
       delegate :find_each, :find_in_batches, :to => :scoped
-      delegate :select, :group, :order, :limit, :joins, :where, :preload, :eager_load, :includes, :from, :lock, :readonly, :having, :to => :scoped
+      delegate :select, :group, :order, :limit, :joins, :where, :preload, :eager_load, :includes, :from, :lock, :readonly, :having, :create_with, :to => :scoped
       delegate :count, :average, :minimum, :maximum, :sum, :calculate, :to => :scoped
 
       # Executes a custom SQL query against your database and returns all the results.  The results will
@@ -801,7 +801,7 @@ module ActiveRecord #:nodoc:
       def reset_column_information
         undefine_attribute_methods
         @column_names = @columns = @columns_hash = @content_columns = @dynamic_methods_hash = @inheritance_column = nil
-        @arel_engine = @unscoped = @arel_table = nil
+        @arel_engine = @relation = @arel_table = nil
       end
 
       def reset_column_information_and_inheritable_attributes_for_all_subclasses#:nodoc:
@@ -904,9 +904,9 @@ module ActiveRecord #:nodoc:
         store_full_sti_class ? name : name.demodulize
       end
 
-      def unscoped
-        @unscoped ||= Relation.new(self, arel_table)
-        finder_needs_type_condition? ? @unscoped.where(type_condition) : @unscoped
+      def relation
+        @relation ||= Relation.new(self, arel_table)
+        finder_needs_type_condition? ? @relation.where(type_condition) : @relation
       end
 
       def arel_table
@@ -923,6 +923,31 @@ module ActiveRecord #:nodoc:
         end
       end
 
+      # Returns a scope for this class without taking into account the default_scope.
+      #
+      #   class Post < ActiveRecord::Base
+      #     default_scope :published => true
+      #   end
+      #
+      #   Post.all          # Fires "SELECT * FROM posts WHERE published = true"
+      #   Post.unscoped.all # Fires "SELECT * FROM posts"
+      #
+      # This method also accepts a block meaning that all queries inside the block will
+      # not use the default_scope:
+      #
+      #   Post.unscoped {
+      #     limit(10) # Fires "SELECT * FROM posts LIMIT 10"
+      #   }
+      #
+      def unscoped
+        block_given? ? relation.scoping { yield } : relation
+      end
+
+      def scoped_methods #:nodoc:
+        key = :"#{self}_scoped_methods"
+        Thread.current[key] = Thread.current[key].presence || self.default_scoping.dup
+      end
+
       private
         # Finder methods must instantiate through this method to work with the
         # single-table inheritance model that makes it possible to create
@@ -1183,11 +1208,6 @@ module ActiveRecord #:nodoc:
           self.default_scoping << construct_finder_arel(options, default_scoping.pop)
         end
 
-        def scoped_methods #:nodoc:
-          key = :"#{self}_scoped_methods"
-          Thread.current[key] = Thread.current[key].presence || self.default_scoping.dup
-        end
-
         def current_scoped_methods #:nodoc:
           scoped_methods.last
         end
diff --git a/activerecord/lib/active_record/named_scope.rb b/activerecord/lib/active_record/named_scope.rb
index ec0a98c6df..c010dac64e 100644
--- a/activerecord/lib/active_record/named_scope.rb
+++ b/activerecord/lib/active_record/named_scope.rb
@@ -25,10 +25,9 @@ module ActiveRecord
       #
       # You can define a \scope that applies to all finders using 
       # ActiveRecord::Base.default_scope.
-      def scoped(options = {}, &block)
+      def scoped(options = nil)
         if options.present?
-          relation = scoped.apply_finder_options(options)
-          block_given? ? relation.extending(Module.new(&block)) : relation
+          scoped.apply_finder_options(options)
         else
           current_scoped_methods ? unscoped.merge(current_scoped_methods) : unscoped.clone
         end
@@ -88,18 +87,22 @@ module ActiveRecord
       #   end
       def scope(name, scope_options = {}, &block)
         name = name.to_sym
+        valid_scope_name?(name)
 
-        if !scopes[name] && respond_to?(name, true)
-          logger.warn "Creating scope :#{name}. " \
-                      "Overwriting existing method #{self.name}.#{name}."
-        end
+        extension = Module.new(&block) if block_given?
 
         scopes[name] = lambda do |*args|
           options = scope_options.is_a?(Proc) ? scope_options.call(*args) : scope_options
 
-          relation = scoped
-          relation = options.is_a?(Hash) ? relation.apply_finder_options(options) : scoped.merge(options) if options
-          block_given? ? relation.extending(Module.new(&block)) : relation
+          relation = if options.is_a?(Hash)
+            scoped.apply_finder_options(options)
+          elsif options
+            scoped.merge(options)
+          else
+            scoped
+          end
+
+          extension ? relation.extending(extension) : relation
         end
 
         singleton_class.send :define_method, name, &scopes[name]
@@ -109,7 +112,15 @@ module ActiveRecord
         ActiveSupport::Deprecation.warn("Base.named_scope has been deprecated, please use Base.scope instead", caller)
         scope(*args, &block)
       end
-    end
 
+    protected
+
+      def valid_scope_name?(name)
+        if !scopes[name] && respond_to?(name, true)
+          logger.warn "Creating scope :#{name}. " \
+                      "Overwriting existing method #{self.name}.#{name}."
+        end
+      end
+    end
   end
 end
diff --git a/activerecord/lib/active_record/persistence.rb b/activerecord/lib/active_record/persistence.rb
index 9e28aa2a05..50166c4385 100644
--- a/activerecord/lib/active_record/persistence.rb
+++ b/activerecord/lib/active_record/persistence.rb
@@ -182,7 +182,7 @@ module ActiveRecord
     def reload(options = nil)
       clear_aggregation_cache
       clear_association_cache
-      @attributes.update(self.class.send(:with_exclusive_scope) { self.class.find(self.id, options) }.instance_variable_get('@attributes'))
+      @attributes.update(self.class.unscoped { self.class.find(self.id, options) }.instance_variable_get('@attributes'))
       @attributes_cache = {}
       self
     end
diff --git a/activerecord/lib/active_record/relation.rb b/activerecord/lib/active_record/relation.rb
index fd0660a138..3b24d4aafd 100644
--- a/activerecord/lib/active_record/relation.rb
+++ b/activerecord/lib/active_record/relation.rb
@@ -16,7 +16,7 @@ module ActiveRecord
     attr_reader :table, :klass
     attr_accessor :extensions
 
-    def initialize(klass, table, &block)
+    def initialize(klass, table)
       @klass, @table = klass, table
 
       @implicit_readonly = nil
@@ -25,12 +25,10 @@ module ActiveRecord
       SINGLE_VALUE_METHODS.each {|v| instance_variable_set(:"@#{v}_value", nil)}
       (ASSOCIATION_METHODS + MULTI_VALUE_METHODS).each {|v| instance_variable_set(:"@#{v}_values", [])}
       @extensions = []
-
-      apply_modules(Module.new(&block)) if block_given?
     end
 
     def new(*args, &block)
-      with_create_scope { @klass.new(*args, &block) }
+      scoping { @klass.new(*args, &block) }
     end
 
     def initialize_copy(other)
@@ -40,11 +38,11 @@ module ActiveRecord
     alias build new
 
     def create(*args, &block)
-      with_create_scope { @klass.create(*args, &block) }
+      scoping { @klass.create(*args, &block) }
     end
 
     def create!(*args, &block)
-      with_create_scope { @klass.create!(*args, &block) }
+      scoping { @klass.create!(*args, &block) }
     end
 
     def respond_to?(method, include_private = false)
@@ -102,6 +100,25 @@ module ActiveRecord
       end
     end
 
+    # Scope all queries to the current scope.
+    #
+    # ==== Example
+    #
+    #   Comment.where(:post_id => 1).scoping do
+    #     Comment.first #=> SELECT * FROM comments WHERE post_id = 1
+    #   end
+    #
+    # Please check unscoped if you want to remove all previous scopes (including
+    # the default_scope) during the execution of a block.
+    def scoping
+      @klass.scoped_methods << self
+      begin
+        yield
+      ensure
+        @klass.scoped_methods.pop
+      end
+    end
+
     # Updates all records with details given if they match a set of conditions supplied, limits and order can
     # also be supplied. This method constructs a single SQL UPDATE statement and sends it straight to the
     # database. It does not instantiate the involved models and it does not trigger Active Record callbacks
@@ -305,7 +322,6 @@ module ActiveRecord
           if where.is_a?(Arel::Predicates::Equality)
             hash[where.operand1.name] = where.operand2.respond_to?(:value) ? where.operand2.value : where.operand2
           end
-
           hash
         end
       end
@@ -328,15 +344,6 @@ module ActiveRecord
       to_a.inspect
     end
 
-    def extend(*args, &block)
-      if block_given?
-        apply_modules Module.new(&block)
-        self
-      else
-        super
-      end
-    end
-
     protected
 
     def method_missing(method, *args, &block)
@@ -364,10 +371,6 @@ module ActiveRecord
 
     private
 
-    def with_create_scope
-      @klass.send(:with_scope, :create => scope_for_create, :find => {}) { yield }
-    end
-
     def references_eager_loaded_tables?
       # always convert table names to downcase as in Oracle quoted table names are in uppercase
       joined_tables = (tables_in_string(arel.joins(arel)) + [table.name, table.table_alias]).compact.map(&:downcase).uniq
diff --git a/activerecord/lib/active_record/relation/query_methods.rb b/activerecord/lib/active_record/relation/query_methods.rb
index 83ae9c6a73..4692271266 100644
--- a/activerecord/lib/active_record/relation/query_methods.rb
+++ b/activerecord/lib/active_record/relation/query_methods.rb
@@ -86,8 +86,9 @@ module ActiveRecord
       clone.tap { |r| r.from_value = value }
     end
 
-    def extending(*modules)
-      clone.tap { |r| r.send :apply_modules, *modules }
+    def extending(*modules, &block)
+      modules << Module.new(&block) if block_given?
+      clone.tap { |r| r.send(:apply_modules, *modules) }
     end
 
     def reverse_order