autoProcessQueue:false

<%=form_for @listing, :html=> { class:'ui form centered black segment'} do |f|%>

   <div class="required field">
     <label>Title</label>
     <%=f.text_field :title,placeholder:'Title of the listing'%>
   </div>

   <div class="field ui segment dropzone dropzone-previews" id='my-dropzone'>
     <p class="dz-message">You can drop an image here or click to upload."
     </p>
   </div>

   <script type="text/javascript">
   Dropzone.autoDiscover=false;
   var myDropzone=new Dropzone("#my-dropzone",
   {
     autoProcessQueue:false,
     url:'/listings',
     paramName:"file",
     addRemoveLinks:true,
     previewsContainer:'.dropzone-previews',
     headers:
     {
        'X-CSRF-Token': $('meta[name="csrf-token"]').attr('content')
     }


    });
    $('.ui.submit').click(function(e){

       myDropzone.autoProcessQueue();
    });
    </script>

 <%end%>