/**
* Create a node
*
* If parentId is not passed in, append to root node
*
* @param string $nodeId A unique identifier for the node
* @param string|null $parentId Which node the node should be append to
* @param mixed $data Arbitrary data
* @param int|null $position Position the node should appear in parent's children
*
* @return Node
* @throws DuplicateNodeException When node id is already in use
*/
public function createNode($nodeId, $parentId = null, $data = null, $position = null)
{
if ($this->nodeExists($nodeId)) {
throw new DuplicateNodeException("ID '{$nodeId}' is already in use. Node ids must be unique.");
}
// use root node if parent id is not passed in
$parent = null === $parentId ? $this->rootNode : $this->nodeCollection->find($parentId);
// create a new node setting position and data
$node = new Node($nodeId, $parent);
$node->setPosition($position);
$node->setData($data);
// add node to parent and collection
$parent->addChild($node);
$this->nodeCollection->add($node);
return $node;
}
