Question

I did the multiple uploads with paperclip based on this app
https://github.com/websymphony/Rails3-Paperclip-Uploadify and it’s working fine, but now I need to build a form where user can delete some of this uploads.

I have this form for deleting the uploads for one product

<%= form_for @product, :html => { :method => :put }, :html => { :multipart => true } do |f| %>
  <h3 id="photos_count"><%= pluralize(@product.uploads.size, "Photo")%></h3>
  <%= f.fields_for :uploads do |photo_fields| %>
    <% if !photo_fields.object.nil? and  !photo_fields.object.new_record? %>
      <%= image_tag(photo_fields.object.photo.url(:thumb)) %>
      <p><%= photo_fields.check_box :_destroy, :class=>'checkbox' %>  Delete item</p>
    <% end %>
  <% end %>
<% end %>

this form somehow displays the correct uploads number, I can see in the terminal window that all uploads with product_id = product.id are found in the database but I have no image displayed in the page as you can see on the image:

Terminal

Started GET "/admin/products/40" for 127.0.0.1 at Tue Apr 10 10:20:06 +0300 2012
  Processing by Admin::ProductsController#show as HTML
  Parameters: {"id"=>"40"}
Creating scope :page. Overwriting existing method AdminUser.page.
  AdminUser Load (2.4ms)  SELECT `admin_users`.* FROM `admin_users` WHERE `admin_users`.`id` = 5 LIMIT 1
Creating scope :page. Overwriting existing method Product.page.
  Product Load (0.5ms)  SELECT `products`.* FROM `products` WHERE `products`.`id` = 40 LIMIT 1
Creating scope :page. Overwriting existing method Upload.page.
  Upload Load (0.4ms)  SELECT `uploads`.* FROM `uploads` WHERE `uploads`.`product_id` = 40 AND (file_avatar = 1) LIMIT 1
Creating scope :page. Overwriting existing method Category.page.
  Category Load (0.4ms)  SELECT `categories`.* FROM `categories` WHERE `categories`.`id` = 2 LIMIT 1
   (0.6ms)  SELECT COUNT(*) FROM `uploads` WHERE `uploads`.`product_id` = 40
Rendered admin/products/_delete_photos.html.erb (154.3ms)
  CACHE (0.0ms)  SELECT COUNT(*) FROM `uploads` WHERE `uploads`.`product_id` = 40

additional info:

upload.rb

class Upload < ActiveRecord::Base
  attr_accessible :product_id, :photo 
  belongs_to :product
  has_attached_file :photo, :styles => { :medium => "300x300>", :thumb => "100x100>" }

  attr_accessible :created_at, :photo_file_size, :photo_file_name, :updated_at, :photo_content_type,
                  :file_avatar, :photo_updated_at, :uploads_attributes, :photo_attributes
end

product.rb

class Product < ActiveRecord::Base
  has_many :uploads, :dependent => :destroy
  accepts_nested_attributes_for :uploads, :allow_destroy => true
end

uploads_controller.rb

  # GET /uploads/1/edit
  def edit
    @upload = Upload.find(params[:id])
  end

  # POST /uploads
  # POST /uploads.xml

  # PUT /uploads/1
  # PUT /uploads/1.xml
  def update
    @upload = Upload.find(params[:id])

    respond_to do |format|
      if @upload.update_attributes(params[:upload])
        format.html { redirect_to(@upload, :notice => 'Upload was successfully updated.') }
        format.xml  { head :ok }
      else
        format.html { render :action => "edit" }
        format.xml  { render :xml => @upload.errors, :status => :unprocessable_entity }
      end
    end
  end

  # DELETE /uploads/1
  # DELETE /uploads/1.xml
  def destroy
    @upload = Upload.find(params[:id])
    @upload.destroy

    respond_to do |format|
      format.html { redirect_to(products_url) }
      format.xml  { head :ok }
    end
  end

so the problem here is: Why the images are not displayed with the checkboxes next to them. Thank you.

Update

Processing by ProductsController#update as HTML
  Parameters: {"commit"=>"Delete sellected photos", "authenticity_token"=>"af5+YybkZ1KMu/DmZmlui9frqQX5ka8v/vvv0hi9PVo=", "id"=>"42", "product"=>{"uploads_attributes"=>{"7"=>{"id"=>"322", "_destroy"=>"1"}, "6"=>{"id"=>"321", "_destroy"=>"0"}, "5"=>{"id"=>"320", "_destroy"=>"0"}, "4"=>{"id"=>"319", "_destroy"=>"0"}, "3"=>{"id"=>"318", "_destroy"=>"0"}, "2"=>{"id"=>"317", "_destroy"=>"0"}, "1"=>{"id"=>"316", "_destroy"=>"0"}, "0"=>{"id"=>"315", "_destroy"=>"0"}}}, "utf8"=>"✓"}

after Jesse’s reply I have now the images in my page, with checkboxes, but the photos are not deleted after I check some of them and press the submit button

products_controller

def update
@product = Product.find(params[:id])

respond_to do |format|
  if @product.update_attributes(params[:product])
    format.html { redirect_to(@product, :notice => 'Product was successfully updated.') }
    format.xml  { head :ok }
  else
    format.html { render :action => "edit" }
    format.xml  { render :xml => @product.errors, :status => :unprocessable_entity }
  end
end

end

Answer 1

You are attempting to use nested_attributes, but have not enabled that on the Product model

class Product < ActiveRecord::Base
  has_many :uploads, dependent: :destroy, autosave: true
  accepts_nested_attributes_for :uploads, allow_destroy: true, reject_if: :all_blank
end

more: http://apidock.com/rails/ActiveRecord/NestedAttributes/ClassMethods/accepts_nested_attributes_for