public function main()
{
$root = RootNode::getInstance();
if (!empty($_REQUEST)) {
if (isset($_REQUEST['command']) && $_REQUEST['command'] == 'add') {
$root->addNode();
} elseif (isset($_REQUEST['command']) && $_REQUEST['command'] == 'delete' && isset($_REQUEST['node']) && null !== $_REQUEST['node']) {
$root->deleteNode((int) $_REQUEST['node']);
}
$root = RootNode::getInstance();
}
$root::output($root);
}
public function deleteNode($i)
{
$root = RootNode::getInstance();
$root->child = null;
$_SESSION['instance'] = serialize($this->rebuild($i, $root));
}