/**
* Attempts to get the previous sibling
*
* @return AbstractNode
* @throws ParentNotFoundException
*/
public function previousSibling()
{
if (is_null($this->parent)) {
throw new ParentNotFoundException('Parent is not set for this node.');
}
return $this->parent->previousChild($this->id);
}
/**
* Sets up the tag of this node.
*
* @param $tag
*/
public function __construct($tag)
{
if (!$tag instanceof Tag) {
$tag = new Tag($tag);
}
$this->tag = $tag;
parent::__construct();
}
/**
* Sets the parent node.
*
* @param InnerNode $parent
* @return $this
* @throws CircularException
*/
public function setParent(InnerNode $parent)
{
// check integrity
if ($this->isDescendant($parent->id())) {
throw new CircularException('Can not add descendant "' . $parent->id() . '" as my parent.');
}
return parent::setParent($parent);
}