<?php
/*
* This file is part of Twig.
*
* (c) Fabien Potencier
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
namespace Twig;
use Twig\Node\Node;
use Twig\NodeVisitor\NodeVisitorInterface;
/**
* A node traverser.
*
* It visits all nodes and their children and calls the given visitor for each.
*
* @author Fabien Potencier <fabien@symfony.com>
*/
final class NodeTraverser
{
private $env;
private $visitors = [];
/**
* @param NodeVisitorInterface[] $visitors
*/
public function __construct(Environment $env, array $visitors = [])
{
$this->env = $env;
foreach ($visitors as $visitor) {
$this->addVisitor($visitor);
}
}
public function addVisitor(NodeVisitorInterface $visitor)
{
$this->visitors[$visitor->getPriority()][] = $visitor;
}
/**
* Traverses a node and calls the registered visitors.
*/
public function traverse(Node $node): Node
{
ksort($this->visitors);
foreach ($this->visitors as $visitors) {
foreach ($visitors as $visitor) {
$node = $this->traverseForVisitor($visitor, $node);
}
}
return $node;
}
/**
* @return Node|null
*/
private function traverseForVisitor(NodeVisitorInterface $visitor, Node $node)
{
$node = $visitor->enterNode($node, $this->env);
foreach ($node as $k => $n) {
if (false !== ($m = $this->traverseForVisitor($visitor, $n)) && null !== $m) {
if ($m !== $n) {
$node->setNode($k, $m);
}
} else {
if (false === $m) {
@trigger_error('Returning "false" to remove a Node from NodeVisitorInterface::leaveNode() is deprecated since Twig version 2.9; return "null" instead.', \E_USER_DEPRECATED);
}
$node->removeNode($k);
}
}
return $visitor->leaveNode($node, $this->env);
}
}
class_alias('Twig\NodeTraverser', 'Twig_NodeTraverser');