Hidden form values updated with multiple submission
You can use jQuery to change the submit button to a loading gif when the save button is clicked. Thus, preventing any more clicks. 

(function($) {
  $('.form-submit').click(function() {
     $('.form-submit').html('&lt;img src="https://media.giphy.com/media/TtZqlvHid7BjW/giphy.gif"&gt;');
  });
})(jQuery);


JS Fiddle Example