I can't upload multiple image using CarrierWave and Ruby on Rails

Question

I'm getting a trouble when I try to use a multi upload file.

this is my form partial view:

<%= simple_form_for @product, :html => { :multipart => true, :class => 'form-horizontal'} do |f| %>
  <%= f.input :name %>
  <%= f.input :description %>
  <%= f.input :price %>
  <%= f.input :isenable, check_box_html: { class: 'check_box' }  %>
  <div class="row-fluid">
    <ul class="thumbnails">
      <%= f.simple_fields_for :attachments do |attachments_form| %>
        <li class="span4">
          <div class="thumbnail">
              <%= image_tag attachments_form.object.image_url(:thumb).to_s if attachments_form.object %>
              <%= attachments_form.label :_destroy, "Borrar Imagen" %>
              <%= attachments_form.file_field :image %>
          </div>
        </li>
      <% end %>
    </ul>
  </div>
  <%= f.button :submit %>
  <%= link_to t('.cancel', :default => t("helpers.links.cancel")),
                products_path, :class => 'btn' %>

<% end %>

This is my controller:

   class ProductsController < ApplicationController
  before_action :set_product, only: [:show, :edit, :update, :destroy]


  # GET /products
  # GET /products.json
  def index
    @products = Product.all
  end

  # GET /products/list
  # GET /products/list.json
  def list
    @products = Product.all
  end

  # GET /products/1
  # GET /products/1.json
  def show
  end

  # GET /products/new
  def new
    @product = Product.new
    3.times do
        attachments = @product.attachments.build
    end
  end

  # GET /products/1/edit
  def edit
  end

  # POST /products
  # POST /products.json
  def create
    @product = Product.new(product_params)

    respond_to do |format|
      if @product.save
        format.html { redirect_to @product, notice: 'Product was successfully created.' }
        format.json { render action: 'show', status: :created, location: @product }
      else
        format.html { render action: 'new' }
        format.json { render json: @product.errors, status: :unprocessable_entity }
      end
    end
  end

  # PATCH/PUT /products/1
  # PATCH/PUT /products/1.json
  def update
    respond_to do |format|
      if @product.update(product_params)
        format.html { redirect_to @product, notice: 'Product was successfully updated.' }
        format.json { head :no_content }
      else
        format.html { render action: 'edit' }
        format.json { render json: @product.errors, status: :unprocessable_entity }
      end
    end
  end

  # DELETE /products/1
  # DELETE /products/1.json
  def destroy
    @product.destroy
    respond_to do |format|
      format.html { redirect_to products_url }
      format.json { head :no_content }
    end
  end

  private
    # Use callbacks to share common setup or constraints between actions.
    def set_product
      @product = Product.find(params[:id])
    end

    # Never trust parameters from the scary internet, only allow the white list through.
    def product_params
      params.require(:product).permit(:name, :description, :price, :isenable, attachments_attributes: [:image, :remove_image])
    end
end

And this is the show file:

<%- model_class = Product -%>
<div class="page-header">
  <h1><%=t '.title', :default => model_class.model_name.human.titleize %></h1>
</div>

<dl class="dl-horizontal">
  <dt><strong><%= model_class.human_attribute_name(:name) %>:</strong></dt>
  <dd class="lead"><%= @product.name %></dd>
  <dt><strong><%= model_class.human_attribute_name(:description) %>:</strong></dt>
  <dd class="lead"><%= @product.description %></dd>
  <dt><strong><%= model_class.human_attribute_name(:price) %>:</strong></dt>
  <dd class="lead"><%= @product.price %></dd>
  <dt><dt>
</dl>
<div class="row-fluid">
  <ul class="thumbnails">
    <% @product.attachments.each do |picture| %>
      <li class="span4">
        <div class="thumbnail">
          <%= image_tag picture.image_url(:full).to_s %>
        </div>
      </li>
    <% end %>
  </ul>
</div>
<div class="form-actions">
  <%= link_to t('.back', :default => t("helpers.links.back")),
              products_path, :class => 'btn'  %>
  <%= link_to t('.edit', :default => t("helpers.links.edit")),
              edit_product_path(@product), :class => 'btn' %>
  <%= link_to t('.destroy', :default => t("helpers.links.destroy")),
              product_path(@product),
              :method => 'delete',
              :data => { :confirm => t('.confirm', :default => t("helpers.links.confirm", :default => 'Are you sure?')) },
              :class => 'btn btn-danger' %>
</div>

I'm using Rails 4.0.0 ruby 2.0.0p247, as I said I'm using CarrierWave to upload files, in the create screen if I left the image empty it creates an empty image object. what I want is to don't create the image if the user don't add a file. Also another problem that I have is related with the remove link. it simple doesn't work. any suggestion?

---

I've solved partially the problem adding the following line to my product model:

accepts_nested_attributes_for :attachments, :allow_destroy => true,
                        :reject_if => lambda {
                          |a| a['image'].blank?
                        }

it allows my to don't insert any image if it hasn't file. so part of my problem is already solved what I need to still solve is the fact that remove link doesn't work.

Answer 1

Ok reviewing the documentation of CarrierWave and principally of Rails documentation I found out the resolution of my problems. The first one as I said before the solution to prevent insert files blank was include in my products model the following line:

accepts_nested_attributes_for :attachments, :allow_destroy => true,
                        :reject_if => lambda {
                          |a| a['image'].blank?
                        }

To solve the problem that CarrierWave doesn't remove the images I found out that when you use nested attributes you should include the :id and :_destroy as permit in your controller like this:

# permit :id and :_destroy

    params.require(:author).permit(:name, books_attributes: [:title, :id, :_destroy])

This is exactly what I did in my controller and also I've changed the name of the checkbox in the view. So in brief the controller was like this:

def product_params
  params.require(:product).permit(:name, :description, :price, :isenable, attachments_attributes: [:image, :_destroy, :id])
end

and the view was in that way:

<label><%= attachments_form.check_box :_destroy %>Borrar Imagen</lable>

Doing that I finally solve both problems, thanks anyway for the help.

Answer 2

In your create action you have to create the attachment, you have to do something like this ..

  @product.attachments.create(:attachment_id).save

where attachment_id is the id of the attachments attached with the product.