title: Multiple uploads with carrierwave without javascript
body: <p>The idea is looping the image array in the controller then store each of them. The request shows correct info about uploaded images </p>
  
  <pre><code>{"utf8"=&gt;"✓",
  "authenticity_token"=&gt;"usbr1ma8uKWBPiVFKh8AKoGYeaZTWAlLXscMBlFYyhw=",
  "painting"=&gt;{"name"=&gt;"",
  "image"=&gt;[#&lt;ActionDispatch::Http::UploadedFile:0x007fb414becad8 @original_filename="union_creek.jpg", @content_type="image/jpeg",
  @headers="Content-Disposition: form-data; name=\"painting[image][]\"; filename=\"union_creek.jpg\"\r\nContent-Type: image/jpeg\r\n",
  @tempfile=#&lt;File:/var/folders/80/2pcl195n7_x0l8bnrjrp4xw40000gn/T/RackMultipart20130105-7179-kr8a7e&gt;&gt;,
  #&lt;ActionDispatch::Http::UploadedFile:0x007fb414beca10 @original_filename="what_lies_beneath.jpg",
  @content_type="image/jpeg",
  @headers="Content-Disposition: form-data; name=\"painting[image][]\"; filename=\"what_lies_beneath.jpg\"\r\nContent-Type: image/jpeg\r\n",
  @tempfile=#&lt;File:/var/folders/80/2pcl195n7_x0l8bnrjrp4xw40000gn/T/RackMultipart20130105-7179-iclmmw&gt;&gt;]},
  "commit"=&gt;"Create Painting",
  "gallery_id"=&gt;"13"}
  </code></pre>
  
  <p>However I got an misleading error when carrierwave attempts to store those of images</p>
  
  <pre><code>Called id for nil, which would mistakenly be 4 -- if you really wanted the id of nil, use object_id
  </code></pre>
  
  <p>The view</p>
  
  <pre><code>= form_for [@gallery, @gallery.paintings.new] do |f|
    %p= f.text_field :name, placeholder: "Enter painting name"
    %p= f.file_field :image, multiple: true
    %p= f.submit %&gt;
  </code></pre>
  
  <p>The controller </p>
  
  <pre><code>uploader = ImageUploader.new
  params[:painting][:image].each do |img|
    uploader.store!(img) # crash here
  end
  </code></pre>
  
  <p>I see something wrong with the controller but I couldn't figure any better way to store multiple files with carrier. </p>
  
  <p>Could anyone point me out ? Thanks</p>