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

1 files changed, 23 insertions, 20 deletions

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