Please verify/merge issue https://github.com/rails/rails/issues/3450

Jan_Varwig · November 27, 2011, 11:28am

I reported this issue a while ago and just got around to writing a test and a fix.

It would be nice if someone could provide a second look and improve or merge this

github.com/rails/rails

Associations with :validate => true are validating stale associations

opened 11:02AM - 27 Oct 11 UTC

closed 09:56AM - 29 Nov 11 UTC

janv

I have two models that looks like this (reduced to the parts relevant to this ex…ample): ``` ruby class Car < ActiveRecord::Base belongs_to :model validates_presence_of :model_id end class Repair < ActiveRecord::Base belongs_to :car, :validate => true def new_car_attributes=(attributes) self.car ||= @new_car = Car.new(attributes) end def new_car @new_car || Car.new(:owner_id => customer_id) end end ``` I am creating a repair like this: ``` ruby customer = FactoryGirl.create(:customer) car = FactoryGirl.create(:car, :owner => customer) params= {"repair"=>{ "new_car_attributes"=>{ "manufacturer_id"=>"", "owner_id"=>customer.id, :kilometers => 123456}, "car_id"=>car.id}} repair = Repair.new(params["repair"]) ``` Now, if I try to save the repair,it fails because "Car is invalid". Reason for this is, that the validation validates the new car (with invalid attributes, missing `model_id`). ### Expected behavior: - Assignment to `car_id` puts the association in a stale state. Trying to access `repair.car` loads the correct car (the one with the id that I assigned to `car_id`) - The validation of the association also recgnizes this (should happen naturally/automatically) and loads the correct car ### Actual behavior: - The validation of the association does not recognize that the current target of the association is stale and tries to validate the car that is currently stored there, the invalid one that was created by the `#new_car_attributes=` setter If I access `#car` first and validate the Repair afterwards, everything is fine because the accessor has updated the target of the association reflection to the correct car. The blame is to be put somewhere here: ``` ruby # activerecord-3.1.1/lib/active_record/autosave_association.rb: 263 # Validate the association if <tt>:validate</tt> or <tt>:autosave</tt> is # turned on for the association. def validate_single_association(reflection) association = association_instance_get(reflection.name) record = association && association.target association_valid?(reflection, record) if record end ``` The record that is validated here is obviously not the same I would get if I called the association accessor on the Model (`repair.car` in our example) This should fix it: ``` ruby def validate_single_association(reflection) association = association_instance_get(reflection.name) record = association && association.read association_valid?(reflection, record) if record end ``` ( a similar change would need to be made in `AutosaveAssociation#associated_records_to_validate_or_save`)

Short description: When creating an association

class Foo

belongs_to :bar, :validate => true

end

the validation does not check if the target of the association proxy is stale and can end up validating an object

that is different from the one you would receive from foo.bar.