Nested Attribute Image Uploads Not Updating (Rails 4/ Carrierwave) - ruby-on-rails

Question

I'm using this example to create multiple image uploads using Carrierwave Rails 4 multiple image or file upload using carrierwave. For some reason if I edit the Post and try to upload a different image it doesn't update.
listings_controller.rb
class ListingsController < ApplicationController
before_action :set_listing, only: [:show, :edit, :update, :destroy]
before_filter :authenticate_user!, :except => [:show, :index]
def index
#listings = Listing.order('created_at DESC')
respond_to do |format|
format.html
format.json { render json: #listings }
end
end
def show
#image_attachments = #listing.image_attachments.all
end
def new
#listing = Listing.new
#listing.user = current_user
#image_attachment = #listing.image_attachments.build
end
def edit
end
def create
#listing = Listing.new(listing_params)
#listing.created_at = Time.now
#listing.user = current_user
respond_to do |format|
if #listing.save
params[:image_attachments]['image'].each do |a|
#image_attachment = #listing.image_attachments.create!(:image => a, :listing_id => #listing.id)
end
format.html { redirect_to #listing, notice: 'Post was successfully created.' }
else
format.html { render action: 'new' }
format.json { render json: #listing.errors, status: :unprocessable_entity }
end
end
end
def update
respond_to do |format|
if #listing.update(listing_params)
flash[:notice] = 'Deal was successfully updated.'
format.html { redirect_to #listing }
format.json { head :no_content }
else
format.html { render action: 'edit' }
format.json { render json: #listing.errors, status: :unprocessable_entity }
end
end
end
def destroy
#listing.destroy
respond_to do |format|
format.html { redirect_to listings_url }
format.json { head :no_content }
end
end
private
# Use callbacks to share common setup or constraints between actions.
def set_listing
#listing = Listing.friendly.find(params[:id])
end
# Never trust parameters from the scary internet, only allow the white list through.
def listing_params
params.require(:listing).permit(:condition, :listing_title, :nickname, :listing_size, :listing_price, :user_id, image_attachments_attributes: [:id, :listing_id, :image])
end
end
listing form
<%= form_for(#listing, :html => { :class => 'form', :multipart => true }) do |f| %>
<% if #listing.errors.any? %>
<div id="error_explanation">
<h2><%= pluralize(#listing.errors.count, "error") %> prohibited this listing from being saved:</h2>
<ul>
<% #listing.errors.full_messages.each do |msg| %>
<li><%= msg %></li>
<% end %>
</ul>
</div>
<% end %>
<%= f.fields_for :image_attachments do |p| %>
<div>
<%= p.label :image %>
<%= p.file_field :image, :multiple => true, name: "image_attachments[image][]", :class => 'upload' %>
</div>
<% end %>
<div class="actions">
<%= f.submit 'Submit', :class => 'submitButton' %>
</div>
<% end %>
listing.rb
has_many :image_attachments
accepts_nested_attributes_for :image_attachments
Any help? Thanks.
UPDATE
This is the log ouput when I try to update the image field. "about.png" is the new image I'm trying to upload.
Started PATCH "/listings/nike-air-max-90" for 127.0.0.1 at 2014-07-16 11:40:14 -0400
Processing by ListingsController#update as HTML
Parameters: {"utf8"=>"✓", "authenticity_token"=>"LU1ADy5JqfuX9CMDtcG/dmGgu9nuvplDQrVixfICsS4=", "listing"=>{"listing_title"=>"Nike Air Max 90", "nickname"=>"", "listing_size"=>"9.5", "listing_price"=>"160", "image_attachments_attributes"=>{"0"=>{"id"=>"1"}}}, "image_attachments"=>{"image"=>[#<ActionDispatch::Http::UploadedFile:0x00000109506810 #tempfile=#<Tempfile:/var/folders/vk/x5f3g8n147z_j39_mzkbfq600000gp/T/RackMultipart20140716-1370-63vlgx>, #original_filename="about.png", #content_type="image/png", #headers="Content-Disposition: form-data; name=\"image_attachments[image][]\"; filename=\"about.png\"\r\nContent-Type: image/png\r\n">]}, "commit"=>"Submit", "id"=>"nike-air-max-90"}
[1m[35mListing Load (0.2ms)[0m SELECT "listings".* FROM "listings" WHERE "listings"."slug" = 'nike-air-max-90' ORDER BY "listings"."id" ASC LIMIT 1
[1m[36mUser Load (0.2ms)[0m [1mSELECT "users".* FROM "users" WHERE "users"."id" = 1 ORDER BY "users"."id" ASC LIMIT 1[0m
[1m[35m (0.1ms)[0m begin transaction
[1m[36mImageAttachment Load (0.1ms)[0m [1mSELECT "image_attachments".* FROM "image_attachments" WHERE "image_attachments"."listing_id" = ? AND "image_attachments"."id" IN (1)[0m [["listing_id", 2]]
[1m[35m (0.1ms)[0m commit transaction
Redirected to http://localhost:3000/listings/nike-air-max-90
Completed 302 Found in 5ms (ActiveRecord: 0.6ms)

Answer 1

Option 1 (Replace all existing attachments with new uploaded ones
In your update action, you are NOT doing what you are doing in create action. Which is this:
params[:image_attachments]['image'].each do |a|
#image_attachment = #listing.image_attachments.create!(:image => a, :listing_id => #listing.id)
end
You can't expect Rails to do this for you magically because this is not a typical use of accepts_nested_attributes feature. In fact, in your current code, you are not using this feature at all.
If you want to make it work with your current code, you will have to delete all existing image_attachments and create the new ones in the update action, like this:
def update
respond_to do |format|
if #listing.update(listing_params)
if params[:image_attachments] && params[:image_attachments]['image']
# delete existing image_attachments
#listing.image_attachments.delete_all
# create new ones from incoming params
params[:image_attachments]['image'].each do |a|
#image_attachment = #listing.image_attachments.create!(:image => a, :listing_id => #listing.id)
end
end
flash[:notice] = 'Deal was successfully updated.'
format.html { redirect_to #listing }
format.json { head :no_content }
else
format.html { render action: 'edit' }
format.json { render json: #listing.errors, status: :unprocessable_entity }
end
end
end
This will replace all existing images with new ones, if you upload new ones.
Option 2 (Edit them individually)
If you want to be able to update existing attachments, you will have to modify the edit form to allow updating attachment records individually. Or do it via proper use of accepts_nested_attributes feature. Cocoon is one great gem help you incorporate nested attributes in your forms easily.