jquery.multiply_fields.js

gistfile1.js

(function($) {
  $.fn.multiply_fields = function(options) {
    var settings = {
      'item': '.item',
      'add-trigger': '.add-trigger',
      'remove-trigger': '.remove-trigger'
    };

    return this.each(function() {
      var methods = {
        update_attr: function(element, attribute, id) {
          $(element).attr(attribute, $(element).attr(attribute).replace(/\d+/, id));
        },

        update_attr_for_input: function(elem, id) {
          elem.children('input').each(function() {
            methods.update_attr(this, 'id', id);
            methods.update_attr(this, 'name', id);
          });
        },

        get_fields: function() {
          return $(settings['item']);
        },

        show_hide_remove_trigger: function() {
          var fields = methods.get_fields();
          var len = fields.length;

          if (len == 1) {
            $(settings['remove-trigger']).hide();
          } else {
            $(settings['remove-trigger']).show();
          }
        },

        add_trigger: function() {
          var fields = methods.get_fields();
          var len = fields.length;
          var pos = new Number(len + 1);
          var new_elem = fields.first().clone();

          methods.update_attr_for_input(new_elem, pos);

          $this.append(new_elem);

          methods.show_hide_remove_trigger();
        },

        remove_trigger: function() {
          $(this).parent(settings['item']).remove();
          methods.show_hide_remove_trigger();
        }
      };

      if (options) {
        $.extend(settings, options);
      }

      var $this = $(this);

      $(settings['add-trigger']).live('click', methods.add_trigger);
      $(settings['remove-trigger']).live('click', methods.remove_trigger);

      methods.show_hide_remove_trigger();
    });
  };
})(jQuery);