Prevent users double-clicking links and form submit buttons and anything else

application.js

$("input[type='submit']").one_click_only();

one_click_only.js

(function($) {
  $.fn.one_click_only = function() {
    this.click(function(event) {
      var now = new Date();
      var previous_click = $(this).data("clicked");
      if (now - previous_click < 500) {
        event.preventDefault();
      }
      $(this).data("clicked", now);
    });
  };
})(jQuery);