accepts_nested_attributes_for和reject_if的回形针问题

Question

I am developing a rails 3 application.

class Post < ActiveRecord::Base
  has_many :attachments
  has_many :photos
  accepts_nested_attributes_for :attachments, :allow_destroy => true, :reject_if => proc { |attrs| attrs['document'].blank? }
  accepts_nested_attributes_for :photos, :allow_destroy => true, :reject_if => proc { |attrs| attrs['image'].blank? }
end

class Attachment < ActiveRecord::Base
  belongs_to :post      
  has_attached_file :document
end

class Photo < ActiveRecord::Base
  belongs_to :post      
  has_attached_file :image, :styles => {
                                         :thumb  => "100x100#",
                                         :small  => "150x150>",
                                         :mid    => "640x640>",
                                         :large  => "800x800>"
                                       }

end

The problem is that "_destroy"=>"1" doesn't work for attachments and photos. I figured out that if I remove reject_if option, it works. What's wrong?

Thanks.

Sam

Answer 1

Seems like since Rails 3.0.3, the association that you want to destroy (attachments, photos) need to be loaded. Take a look at this ticket . A quick fix, which isn't so elegant is to load your association in your update method:

@post = Post.includes(:attachments).find(params[:id])

if @post.update_attributes(params[:post])
  redirect_to(posts_url, :notice => 'Post updated.'
else
  render :action => "edit"
end

FYI this is still necessary for Rails 3.0.4.