Add CollectionProxy#scope

This can be used to get a Relation from an association.

Previously we had a #scoped method, but we're deprecating that for
AR::Base, so it doesn't make sense to have it here.

This was requested by DHH, to facilitate code like this:

    Project.scope.order('created_at DESC').page(current_page).tagged_with(@tag).limit(5).scoping do
      @topics      = @project.topics.scope
      @todolists   = @project.todolists.scope
      @attachments = @project.attachments.scope
      @documents   = @project.documents.scope
    end

1 files changed, 5 insertions, 1 deletions

diff --git a/activerecord/lib/active_record/associations/collection_proxy.rb b/activerecord/lib/active_record/associations/collection_proxy.rb
index 65a5044a3d..3a7a488302 100644
--- a/activerecord/lib/active_record/associations/collection_proxy.rb
+++ b/activerecord/lib/active_record/associations/collection_proxy.rb
@@ -855,7 +855,8 @@ module ActiveRecord
         @association.scoped.scoping { yield }
       end
 
-      def spawn
+      # Returns a <tt>Relation</tt> object for the records in this association
+      def scope
         association = @association
 
         @association.scoped.extending! do
@@ -863,6 +864,9 @@ module ActiveRecord
         end
       end
 
+      # :nodoc:
+      alias spawn scope
+
       # Equivalent to <tt>Array#==</tt>. Returns +true+ if the two arrays
       # contain the same number of elements and if each element is equal
       # to the corresponding element in the other array, otherwise returns