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polymorphic belongs_to association with touch: true updates old recor…

…d correctly

Example: Given you have a comments model with a polymorphic commentable
association (e.g. books and songs) with the touch option set.
Every time you update a comment its commentable should be touched.
This was working when you changed attributes on the comment or when you
moved the comment from one book to another. However, it was not working
when moving a comment from a book to a song. This is now fixed.
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1 parent f0c5862 commit f1a646fa74290db32fb52bb373791891ab73d693 @severin severin committed Dec 5, 2013
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14 activerecord/CHANGELOG.md
@@ -1,3 +1,17 @@
+* Polymorphic belongs_to associations with the `touch: true` option set update the timestamps of
+ the old and new owner correctly when moved between owners of different types.
+
+ Example:
+
+ class Rating < ActiveRecord::Base
+ belongs_to :rateable, polymorphic: true, touch: true
+ end
+
+ rating = Rating.create rateable: Song.find(1)
+ rating.update_attributes rateable: Book.find(2) # => timestamps of Song(1) and Book(2) are updated
+
+ *Severin Schoepke*
+
* Improve formatting of migration exception messages: make them easier to read
with line breaks before/after, and improve the error for pending migrations.
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8 activerecord/lib/active_record/associations/builder/belongs_to.rb
@@ -91,7 +91,13 @@ def self.touch_record(o, foreign_key, name, touch) # :nodoc:
old_foreign_id = o.changed_attributes[foreign_key]
if old_foreign_id
- klass = o.association(name).klass
+ association = o.association(name)
+ reflection = association.reflection
+ if reflection.polymorphic?
+ klass = o.public_send("#{reflection.foreign_type}_was").constantize
+ else
+ klass = association.klass
+ end
old_record = klass.find_by(klass.primary_key => old_foreign_id)
if old_record
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58 activerecord/test/cases/timestamp_test.rb
@@ -272,36 +272,62 @@ def self.name; 'Toy'; end
assert_not_equal time, old_pet.updated_at
end
- def test_changing_parent_of_a_record_touches_both_new_and_old_polymorphic_parent_record
- klass = Class.new(ActiveRecord::Base) do
- def self.name; 'Toy'; end
+ def test_changing_parent_of_a_record_touches_both_new_and_old_polymorphic_parent_record_changes_within_same_class
+ car_class = Class.new(ActiveRecord::Base) do
+ def self.name; 'Car'; end
end
- wheel_klass = Class.new(ActiveRecord::Base) do
+ wheel_class = Class.new(ActiveRecord::Base) do
def self.name; 'Wheel'; end
belongs_to :wheelable, :polymorphic => true, :touch => true
end
- toy1 = klass.find(1)
- toy2 = klass.find(2)
+ car1 = car_class.find(1)
+ car2 = car_class.find(2)
- wheel = wheel_klass.new
- wheel.wheelable = toy1
- wheel.save!
+ wheel = wheel_class.create!(wheelable: car1)
time = 3.days.ago.at_beginning_of_hour
- toy1.update_columns(updated_at: time)
- toy2.update_columns(updated_at: time)
+ car1.update_columns(updated_at: time)
+ car2.update_columns(updated_at: time)
- wheel.wheelable = toy2
+ wheel.wheelable = car2
wheel.save!
- toy1.reload
- toy2.reload
+ assert_not_equal time, car1.reload.updated_at
+ assert_not_equal time, car2.reload.updated_at
+ end
+
+ def test_changing_parent_of_a_record_touches_both_new_and_old_polymorphic_parent_record_changes_with_other_class
+ car_class = Class.new(ActiveRecord::Base) do
+ def self.name; 'Car'; end
+ end
+
+ toy_class = Class.new(ActiveRecord::Base) do
+ def self.name; 'Toy'; end
+ end
+
+ wheel_class = Class.new(ActiveRecord::Base) do
+ def self.name; 'Wheel'; end
+ belongs_to :wheelable, :polymorphic => true, :touch => true
+ end
+
+ car = car_class.find(1)
+ toy = toy_class.find(3)
+
+ wheel = wheel_class.create!(wheelable: car)
+
+ time = 3.days.ago.at_beginning_of_hour
+
+ car.update_columns(updated_at: time)
+ toy.update_columns(updated_at: time)
+
+ wheel.wheelable = toy
+ wheel.save!
- assert_not_equal time, toy1.updated_at
- assert_not_equal time, toy2.updated_at
+ assert_not_equal time, car.reload.updated_at
+ assert_not_equal time, toy.reload.updated_at
end
def test_clearing_association_touches_the_old_record

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