title: Rails 4 not using Remotipart to remotely submit form
body: <p>It looks like Remotipart isn't actually being used to submit my form, so the image is completely left out when I look at the params where the form gets submitted to. </p>
  
  <p><code>remotipart_submitted?</code> returns false</p>
  
  <p>params: <code>{"utf8"=&gt;"✓", "product"=&gt;{"name"=&gt;"RemotipartFails", "price"=&gt;"10", "description"=&gt;"Please work"}, "action"=&gt;"create", "controller"=&gt;"products"}</code></p>
  
  <p>Below is more relevant code</p>
  
  <h2>Gems</h2>
  
  <pre><code>gem "jquery-rails"
  gem "remotipart", "~&gt; 1.2"
  </code></pre>
  
  <h2>Javascript</h2>
  
  <pre><code>//= require jquery
  //= require jquery_ujs
  //= require jquery.remotipart
  </code></pre>
  
  <h2>Form</h2>
  
  <pre><code>&lt;%= form_for(:product, url: products_path, remote: true, html: { multipart: true, class: "form-horizontal" }) do |f| %&gt;
    &lt;div class="margin-top-10 margin-bottom-10"&gt;
      &lt;div class="input-left"&gt;
        &lt;%= f.text_field :name, { placeholder: "Name", class: "form-control" } %&gt;
      &lt;/div&gt;
      &lt;div class="input-right"&gt;
        &lt;%= f.number_field :price, { placeholder: "Price", class: "form-control" } %&gt;
      &lt;/div&gt;
      &lt;div class="clearfix margin-bottom-10"&gt;&lt;/div&gt;
      &lt;div class="input-full"&gt;
        &lt;%= f.text_field :description, { placeholder: "Description", class: "form-control" } %&gt;
      &lt;/div&gt;
      &lt;div class="clearfix margin-bottom-10"&gt;&lt;/div&gt;
      &lt;div class="input-full"&gt;
        &lt;%= f.file_field :image, { class: "form-control" } %&gt;
      &lt;/div&gt;
      &lt;div class="clearfix margin-bottom-10"&gt;&lt;/div&gt;
      &lt;%= f.submit "Add Product", class: "btn btn-green" %&gt;
    &lt;/div&gt;
  &lt;% end %&gt;
  </code></pre>
  
  <p>I've tried it without the <code>multipart: true</code> because I think form_for adds it automatically, but that didn't help.</p>
  
  <p>At this point I'm open to alternative solutions (hopefully allowing me to submit the form remotely with an image still)</p>