Paperclip error - Can't mass-assign protected attributes - ruby-on-rails-3

Question

I know there are a couple questions around this topic, one is almost identical since we followed the same tutorial, but none of the answers are working for me. I followed emerson lackey's tutorial on attaching multiple images with paperclip (http://emersonlackey.com/screencasts/rails-3-with-paperclip.mov) and am having the error Can't mass-assign protected attributes: assets_attributes. One note as you look at the code, I had been running with only image per post so there is terminology for images vs. assets that will be deleted but need right now for the rest of the site to work.
I have created an Asset ID and added it to the asset model. Also note that I have Pins instead of Posts.
In the pin.rb Model:
class Pin < ActiveRecord::Base
attr_accessible :description, :image, :image_remote_url, :Designer, :price, :retail_value, :condition, :lender_notes, :size, :material, :color, :classification, :item_category, :asset_attributes
validates :user_id, presence: true
validates :description, presence: true
validates :Designer, presence: true
validates :size, presence: true
validates :color, presence: true
validates :material, presence: true
validates :price, presence: true
validates :retail_value, presence: true
validates :condition, presence: true
validates :lender_notes, presence: true
validates :classification, presence: true
validates :item_category, presence: true
validates_attachment :asset, presence: true,
content_type: { content_type: ['image/jpeg', 'image/jpg', 'image/png', 'image/gif'] },
size: { less_than: 5.megabytes }
belongs_to :user
has_many :line_items
has_many :assets
accepts_nested_attributes_for :assets, :allow_destroy => true
before_destroy :ensure_not_referenced_by_any_line_item
has_attached_file :image, styles: { medium: "320x240"}
# ensure that there are no line items referencing this product
def ensure_not_referenced_by_any_line_item
if line_items.empty?
return true
else
errors.add(:base, 'Line Items present')
return false
end
end
def image_remote_url=(url_value)
self.image = URI.parse(url_value) unless url_value.blank?
super
end
end
In the asset.rb model:
class Asset < ActiveRecord::Base
attr_accessible :asset
belongs_to :pin
has_attached_file :asset, :styles => { :large => "640x480", :medium => "320x240", :thumb => "100x100>" }
end
in the pins_controller.rb file:
class PinsController < ApplicationController
before_filter :authenticate_user!, except: [:index]
def index
#pins = Pin.order("created_at desc").page(params[:page]).per_page(20)
respond_to do |format|
format.html # index.html.erb
format.json { render json: #pins }
format.js
end
end
def show
#pin = Pin.find(params[:id])
respond_to do |format|
format.html # show.html.erb
format.json { render json: #pin }
end
end
def new
#pin = current_user.pins.new
5.times { #pin.assets.build }
respond_to do |format|
format.html # new.html.erb
format.json { render json: #pin }
end
end
def edit
#pin = current_user.pins.find(params[:id])
5.times { #pin.assets.build }
end
def create
#pin = current_user.pins.new(params[:pin])
respond_to do |format|
if #pin.save
format.html { redirect_to #pin, notice: 'Pin was successfully created.' }
format.json { render json: #pin, status: :created, location: #pin }
else
format.html { render action: "new" }
format.json { render json: #pin.errors, status: :unprocessable_entity }
end
end
end
def update
#pin = current_user.pins.find(params[:id])
respond_to do |format|
if #pin.update_attributes(params[:pin])
format.html { redirect_to #pin, notice: 'Pin was successfully updated.' }
format.json { head :no_content }
else
format.html { render action: "edit" }
format.json { render json: #pin.errors, status: :unprocessable_entity }
end
end
end
def destroy
#pin = current_user.pins.find(params[:id])
#pin.destroy
respond_to do |format|
format.html { redirect_to pins_url }
format.json { head :no_content }
end
end
end
In the _form.html.erb file:
<%= simple_form_for(#pin, :html => { :multipart => true}) do |f| %>
<%= f.full_error :asset_file_size, class: "alert alert-error" %>
<%= f.full_error :asset_content_type, class: "alert alert-error" %>
<%= f.fields_for :assets do |asset_fields| %>
<%= asset_fields.file_field :asset %>
<% end %>
<div class="form-actions">
<%= f.button :submit, class: "btn btn-primary" %>
</div>
<% end %>
Thank you!!!!!

Answer 1

You said the error is:
Can't mass-assign protected attributes: assets_attributes
You don't have this defined in attr_accessible; you have :asset_attributes but not :assets_attributes
Try changing it to the plural version.