Appends an `add` button to all `.multiple-items` rendered by fungiform for adding `Multiple` or `MultiChoiceField` in the DOM

jquery.fungiform.js

(function(){
  var resetLi = function($li, index){
    $li.find(":input, label").each(function(i){
      var $that = $(this);
      $.each(['name', 'id', 'for'], function(i, attribute){
        var value = $that.attr(attribute);
        if(value){
          $that.attr(attribute, value.replace(/\d+/, index))
        }
      });
      $that.val("");
    });
    return $li;
  };
  $(".multiple-items").each(function(){
    var $parent = $(this),
        $add = $('<a href="#" class="add">Add</a>');
    $add.click(function(e){
      e.preventDefault();
      var $li = $parent.find("li:last").clone(),
          name = $(':input[name]', $li).attr('name');
      if(name.search(/\d+/)>-1){
        var index = Number(name.match(/\d+/)[0]);
        $parent.append(resetLi($li, index + 1));
      }
    });
    $parent.after($add);
  });
})();