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