From b2fa70a8e1a7a02873e54bb38abafabdd103476a Mon Sep 17 00:00:00 2001
From: Marcel Molina <marcel@vernix.org>
Date: Wed, 23 Jan 2008 17:06:40 +0000
Subject: Indicate in documentation that newer version of AR support eager
loading in polymorphic associations. Closes #10861 [fxn]
git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@8707 5ecf4fe2-1ee6-0310-87b1-e25e094e27de
---
activerecord/lib/active_record/associations.rb | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
(limited to 'activerecord/lib')
diff --git a/activerecord/lib/active_record/associations.rb b/activerecord/lib/active_record/associations.rb
index 3692be3aeb..cb17b6e483 100755
--- a/activerecord/lib/active_record/associations.rb
+++ b/activerecord/lib/active_record/associations.rb
@@ -487,7 +487,8 @@ module ActiveRecord
# When eager loaded, conditions are interpolated in the context of the model class, not the model instance. Conditions are lazily interpolated
# before the actual model exists.
#
- # Eager loading is not possible with polymorphic associations. Given
+ # Eager loading is not supported with polymorphic associations up to (and including)
+ # version 2.0.2. Given
#
# class Address < ActiveRecord::Base
# belongs_to :addressable, :polymorphic => true
@@ -500,6 +501,9 @@ module ActiveRecord
# will raise <tt>ActiveRecord::EagerLoadPolymorphicError</tt>. The reason is that the parent model's type
# is a column value so its corresponding table name cannot be put in the FROM/JOIN clauses of that early query.
#
+ # In versions greater than 2.0.2 eager loading in polymorphic associations is supported
+ # thanks to a change in the overall preloading strategy.
+ #
# It does work the other way around though: if the <tt>User</tt> model is <tt>addressable</tt> you can eager load
# their addresses with <tt>:include</tt> just fine, every piece needed to construct the query is known beforehand.
#
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