     maxThumbnailFilesize: 2 # in MB. When the filename exceeds this limit, the thumbnail will not be generated.
     thumbnailWidth: 100
     thumbnailHeight: 100
+
+    # Can be an object of additional parameters to transfer to the server.
+    # This is the same as adding hidden input fields in the form element.
+    params: { }
 
     clickable: yes
 

        if !input.attr("type") or input.attr("type").toLowerCase() != "checkbox" or inputElement.checked
          formData.append input.attr("name"), input.val()

    # Has to be last because some servers (eg: S3) expect the file to be the
    # last parameter
    formData.append @options.paramName, file


    formData = new FormData()

    # Adding all @options parameters
    formData.append name, key for key, name of @options.params if @options.params

    # Take care of other input elements
    if @elementTagName = "FORM"
      for inputElement in @element.find "input, textarea, select, button"
        input = o inputElement
        inputName = input.attr("name")
