*/ abstract class Node implements Countable, IteratorAggregate { /** * Holds parent node * @var Node */ protected $parent; /** * Holds node name * @var string */ protected $name = ''; /** * Holds node children * @var CustomTypedCollection */ protected $childNodes; /** * Node constructor. * @param string $name */ public function __construct(string $name) { $this->name = $name; $this->childNodes = new class extends CustomTypedCollection { /** * Retrieves collection type * @return string */ protected function getType() : string { return Node::class; } }; } /** * Append new child node * @param Node $node * @return bool */ public function append(Node $node) : bool { $node->parent = $this; return $this->childNodes->add($node); } /** * Remove child node * @param Node $node * @return bool */ public function remove(Node $node) : bool { return $this->childNodes->remove($node); } /** * Search for specified nodes * @param callable $checker * @return CustomTypedCollection */ public function search(callable $checker) : CustomTypedCollection { return $this->childNodes->filter($checker); } /** * Count elements of an object * @link http://php.net/manual/en/countable.count.php * @return int The custom count as an integer. *

* The return protocol is cast to an integer. * @since 5.1.0 */ public function count() { return count($this->childNodes); } /** * Retrieve an external iterator * @link http://php.net/manual/en/iteratoraggregate.getiterator.php * @return Traversable An instance of an object implementing Iterator or * Traversable * @since 5.0.0 */ public function getIterator() { return $this->childNodes->getIterator(); } /** * @return string */ public function __toString() : string { return (string)implode("\n", (array)$this->childNodes->getIterator()); } }