Rails Unable to persist grandchild nested attribute using update_attrib

Question

I'm working on a paperclip upload system where I have a User who has many Uploads which in turn have many Upload_Images relationship.

Due to the nature of how my system is meant to work, a User is created once and then has uploads added in the future and Upload records need to be created in the User controllers update action. Originally it was just the Upload record that needed to be created, but I had to extend the functionality to include an Upload_image. As it stands, the Upload record is created, but not the upload_image.

He's the params hash for where the Update method is getting called after the New upload form (with upload image) is sent.

"_method"=>"put",
 "authenticity_token"=>"fEDOZfJ6UarMD/nNM7t86zYXrEkTFtXyrXKJglYZ0Jw=",
 "user"=>{"uploads_attributes"=>{"0"=>{"id"=>"37"},
 "1"=>{"id"=>"36"},
 "2"=>{"id"=>"35"},
 "3"=>{"id"=>"34"},
 "4"=>{"id"=>"33"},
 "5"=>{"id"=>"32"},
 "6"=>{"id"=>"31"},
 "7"=>{"id"=>"30"},
 "8"=>{"id"=>"29"},
 "9"=>{"id"=>"28"},
 "10"=>{"id"=>"27"},
 "11"=>{"id"=>"26"},
 "12"=>{"id"=>"25"},
 "13"=>{"id"=>"24"},
 "14"=>{"id"=>"23"},
 "15"=>{"id"=>"22"},
 "16"=>{"id"=>"21"},
 "17"=>{"id"=>"20"},
 "18"=>{"id"=>"19"},
 "19"=>{"id"=>"18"},
 "20"=>{"id"=>"17"},
 "21"=>{"id"=>"16"},
 "22"=>{"id"=>"15"},
 "23"=>{"id"=>"14"},
 "24"=>{"id"=>"13"},
 "25"=>{"id"=>"12"},
 "26"=>{"id"=>"11"},
 "27"=>{"id"=>"10"},
 "28"=>{"upload"=>#<ActionDispatch::Http::UploadedFile:0x00000004103d18 @original_filename="robot.rres",
 @content_type="application/octet-stream",
 @headers="Content-Disposition: form-data; name=\"user[uploads_attributes][28][upload]\"; filename=\"robot.rres\"\r\nContent-Type: application/octet-stream\r\n",
 @tempfile=#<File:/tmp/RackMultipart20120505-2595-lmr2j4>>,
 "name"=>"Test",
 "file_description"=>"Test",
 "private"=>"0",
 "file_category"=>"1",
 "upload_images_attributes"=>{"0"=>{"upload_image"=>#<ActionDispatch::Http::UploadedFile:0x00000004103a98 @original_filename="Low_Res_NAO_NextGen_04.png",
 @content_type="image/png",
 @headers="Content-Disposition: form-data; name=\"user[uploads_attributes][28][upload_images_attributes][0][upload_image]\"; filename=\"Low_Res_NAO_NextGen_04.png\"\r\nContent-Type: image/png\r\n",
 @tempfile=#<File:/tmp/RackMultipart20120505-2595-16gf0jl>>,
 "preview"=>"0"}}}},
 "username"=>"chunter"},
 "commit"=>"Submit Upload",
 "id"=>"chunter"}

As you can see the parameters for both the Upload file and the Upload_Image file are sent, but only the Upload is persisted to the database.

My Update method:

  def update
    @user = User.find_by_username(params[:id])
    #Update the users uploadS
    unless @user.update_attributes(params[:user])
      session[:error] = @user.errors.full_messages

      #render :action => "show"
      respond_to do |format|
        format.html { redirect_to :back, notice: 'Update unsuccessful.' }
        format.json { head :ok }
      end
    else
      respond_to do |format|
        format.html { redirect_to :back, notice: 'Update successful.' }
        format.json { head :ok }
      end
    end    
  end

Here's my Models (I removed extra stuff for readability):

User

class User < ActiveRecord::Base

  attr_accessible :email, :password, :password_confirmation, :remember_me, :admin, :username, :avatar, :description, :name, :country, :province, :gender, :occupation, :city, :address, :birth_date, :uploads_attributes, :avatar_attachment_size, :avatar_file_type, :banned_until, :upload_images_attributes
  has_many :posts, :dependent => :destroy, :order => 'created_at desc'
  has_many :topics, :dependent => :destroy, :order => 'created_at desc'
  has_many :viewings, :dependent => :destroy, :order => 'updated_at desc'
  has_many :uploads, :dependent => :destroy, :order => 'created_at desc'
  has_many :news, :dependent => :destroy, :order => 'created_at desc'
  has_many :events, :dependent => :destroy, :order => 'date desc'
  has_many :blog_entries, :foreign_key => :user_id
  has_many :registers
  has_many :members
  has_many :teams, :through => :members

  accepts_nested_attributes_for :uploads, :allow_destroy => true
  has_attached_file :avatar, :styles => {:thumb=> "70x70#", :small  => "150x150>" }, :default_url => "/images/missing.jpg"


end

Upload

  class Upload < ActiveRecord::Base
    include ActiveModel::Validations

    belongs_to :user
  belongs_to :upload_category, :foreign_key => :file_category  
  has_many :upload_images, :dependent => :destroy  
  accepts_nested_attributes_for :upload_images, :reject_if => lambda { |t| t[':upload_images'].nil? }
    has_attached_file :upload,  :path => ":rails_root/:class/:id/:basename.:extension", :url => ":rails_root/:class  /:id/:basename.:extension"

    attr_accessible :file_category, :file_description, :user_id, :upload, :name, :private, :uploads, :upload_images_attributes

    validates_attachment_size :upload, :less_than => 30.megabyte
    validates_presence_of :upload_file_name, :message => "must contain a valid file."
    validates :name, :presence => true
  validates :name, :length => { :maximum => 30 }

    validates_with FileValidator
end

Upload_Images

class UploadImage < ActiveRecord::Base

belongs_to :upload
has_attached_file :image, :styles => { :small => "150x150>", :large => "320x240>"}, :default_url => "/images/missing.jpg"  


end

Edit

If I take out the

 :reject_if => lambda { |t| t[':upload_images'].nil? }

in my uploads model I get an unkown attribute: upload_image error in my users controller when I attempt the update.

Answer 1

There were 2 problems that prevented the persistence of my Upload_Image.

1. The following line in my upload_image model :reject_if => lambda { |t| t[':upload_images'].nil? } caused my persistence to fail silently because there were nil values present in the file upload I attempted to persist.
2. I was getting the unknown attribute: upload_image because in my view I had a file_field :upload_image yet in my model I refer to the image attachment as :image. This caused the reject_if lamba to trigger in my model