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[PATCH] add :update_only option to accepts_nested_attributes_for
This option adds the ability for one-to-one associations to say "no i dont want the user to be able to create a new record just by leaving out the :id attribute", because at least in one of our applications, this would screw things up.
class Car < ActiveRecord::Base
has_one :engine
accepts_nested_attributes_for :engine, :update_only => true
end
class Engine < ActiveRecord::Base
belongs_to :car
end
car = Car.create(:name => "Slow Car")
# this creates a new engine, since no engine exists
car.engine_attributes = {:ps => 40}
car.save!
# tunes the existing engine, doesn't create a new engine
car.engine_attributes = {:ps => 200}
car.save!
# does the same thing as above, :id is in fact ignored
car.engine_attributes = {:ps => 210, :id => car.engine.id}
car.save!
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Michael Siebertnow this is the patch with working tests (i forgot to rename the option in the tests, shame on me)
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José ValimThe patch looks good, one suggestion though, those lines are duplicated:
unless reject_new_record?(association_name, attributes) send("build_#{association_name}", attributes.except(*UNASSIGNABLE_KEYS)) endYou might get around it just changing the first conditional to:
if update_only && existing_record = send(association_name) -
Joshua White
- Assigned user set to Eloy Duran
I wrote the exact same sort of thing a few months back. There was a bit of discussion and I talked with Eloy a bit as well.
My patch added two options, each applying to one sort of association. For one_to_ones I created blank_id_updates_existing_one_to_one (same as your update_only just requires there to be a blank, or the same id. Different ids wouldn't make sense anyways so its just semantics on that point.
The important point for me was for collections I created :destroy_missing.
I use a lot of 2-3 level nested forms and what destroy_missing does is it will actually delete nested attributes that aren't returned. Its dangerous, but in my case entirely safe, the nested objects I use this on are has_many and belongs_to, so if they aren't returned, it means they are no longer needed. ~six lines reduced my flex and html frontend logic and my controller logic, as well as transmission size.
I've been using this module as a replacement for nested_attributes all over my application since then, and both options have worked perfectly thus far, and I'd really like to see both your update_only options and my destroy_missing options included in the next build.
Is it reasonable to submit my destroy_missing features as a patch as well? I think it scares some people, but its just a few lines, doesn't even begin to effect the default behavior, saves the developer a LOT of hassle and repeated code, and is easier on the database then other methods. Any suggestions?
Thanks
-Josh-
dangerous_nested_attributes.rb
14.5 KB
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Repository
- State changed from new to resolved
(from [7074c5a6294a0f53839accd53a4314af37d19248]) Add an :update_only option to accepts_nested_attributes_for for to-one associations. [#2563 state:resolved]
Signed-off-by: Eloy Duran eloy.de.enige@gmail.com
http://github.com/rails/rails/commit/7074c5a6294a0f53839accd53a4314... -
Eloy Duran@Joshua Yes, please create a patch. Since I know you've been using it for a while, it seems to me it's time to go in Rails. Thanks
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Repository
(from [07b615fb897017d7acfaafa88606bc88be30f6e4]) Add an :update_only option to accepts_nested_attributes_for for to-one associations. [#2563 state:resolved]
Signed-off-by: Eloy Duran eloy.de.enige@gmail.com
http://github.com/rails/rails/commit/07b615fb897017d7acfaafa88606bc... -