accepts_nested_attributes_for raises NoMethodError when saving polymorphic belongs_to

I think this might be the same problem that I am having as detailed in this post:

http://railsforum.com/viewtopic....

Will this fix work for the problems I'm having with has_manuy :through associations?
https://rails.lighthouseapp.com/projects/8994-ruby-on-rails/tickets...

@jamesw No it won't. This patch will simply raise an exception with a more human friendly messages. As the OP stated: ‘This patch will give a friendlier ArgumentError "Cannot build association looter. Are you trying to build a polymorphic one-to-one association?"’

Thank you very much for clarifying that.

@eloy Is there a reason we wouldn't put this in master also?

@eloy, No I'm not trying to build a polymorphic one-to-one. Merely a nested association when the association is a has_many :through.I'm happy to provide further details of my exact scenario (rather than the contrived one I came up with for testing) just let me know.

Sorry it took so long to respond to your question properly, I only just noticed it.

@Mike Nope, no reason at all, good question :). My thought was that it would be pulled in by those working on master. I'll take that up with Michael though.

@jamesw I didn't ask you a question, I quoted (see the quotes) the error message that will be raised when this patch is applied. Please read the whole ticket carefully to fullty understand what this ticket is about; it has nothing to do with your issues.

@jamesw Check out http://railsforum.com/viewtopic.php?pid=93381#93381 This might be the same issue you are having. Haven't seen a fix that works.

Not a fix, but a workaround:

class Treasure < ActiveRecord::Base
  belongs_to :looter, :polymorphic => true

  accepts_nested_attributes_for :looter

  def build_looter(params)
    self.looter = xxx.new(params)
  end

end

To figure out the polymorphic class I passed a variable within the params hash (just a hidden field in the form).

Works like a charm...

Mike - your workaround didn't work for me. When I do something along those lines for my models and try to do the equivalent of

@@@params = {:name => "pearl", :looter_attributes => {:catchphrase => "Arrr!"}} Treasure.new params@@@

I no longer get the NoMethodError bit but instead an "ActiveRecord::UnknownAttributeError: unknown attribute: looter_attributes" in response. In fact I'm getting this same error for another nesting which operates through the has many side of a polymorphic relationship. Has anyone else experienced this issue?

I saw Mike's general approach to solving the problem at http://www.travisdunn.com/rails-polymorphic-belongs_to-associations... and after getting to here found this post, so I thought I would share.

Any ideas why I might be getting these errors and/or how to get rid of them?

(from [bcd0ef710ec6d2cc6b880c39de0dfacc07df85e4]) Raise an exception with friendlier error message when attempting to build a polymorphic belongs_to with accepts_nested_attributes_for. [#2318 accepts_nested_attributes_for raises NoMethodError when saving polymorphic be... state:resolved] Signed-off-by: Eloy Duran eloy.de.enige@gmail.com
http://github.com/rails/rails/commit/bcd0ef710ec6d2cc6b880c39de0dfa...

omega watch