/*
 * call-seq:
 *  optional_attributes
 *
 * A list of optional attributes for this element
 */
static VALUE optional_attributes(VALUE self)
{
  htmlElemDesc * description;
  VALUE list;
  int i;

  Data_Get_Struct(self, htmlElemDesc, description);

  list = rb_ary_new();

  if(NULL == description->attrs_opt) return list;

  for(i = 0; description->attrs_opt[i]; i++) {
    rb_ary_push(list, NOKOGIRI_STR_NEW2(description->attrs_opt[i]));
  }

  return list;
}