/** * Returns this node's ID. * * @return string */ public function getId() { if (!isset($this->cache['id'])) { if ($this->parent === NULL) { $this->cache['id'] = 'index'; } else { $parentId = $this->parent->getId(); if ($parentId == 'index') { $this->cache['id'] = $this->getName(); } else { $this->cache['id'] = $parentId . '_' . $this->getName(); } } } return $this->cache['id']; }