Matthias Andreas Benkard | 12a5735 | 2021-12-28 18:02:04 +0100 | [diff] [blame^] | 1 | <?php |
| 2 | |
| 3 | /* |
| 4 | * This file is part of Twig. |
| 5 | * |
| 6 | * (c) Fabien Potencier |
| 7 | * |
| 8 | * For the full copyright and license information, please view the LICENSE |
| 9 | * file that was distributed with this source code. |
| 10 | */ |
| 11 | |
| 12 | namespace Twig; |
| 13 | |
| 14 | use Twig\Node\Node; |
| 15 | use Twig\NodeVisitor\NodeVisitorInterface; |
| 16 | |
| 17 | /** |
| 18 | * A node traverser. |
| 19 | * |
| 20 | * It visits all nodes and their children and calls the given visitor for each. |
| 21 | * |
| 22 | * @author Fabien Potencier <fabien@symfony.com> |
| 23 | */ |
| 24 | final class NodeTraverser |
| 25 | { |
| 26 | private $env; |
| 27 | private $visitors = []; |
| 28 | |
| 29 | /** |
| 30 | * @param NodeVisitorInterface[] $visitors |
| 31 | */ |
| 32 | public function __construct(Environment $env, array $visitors = []) |
| 33 | { |
| 34 | $this->env = $env; |
| 35 | foreach ($visitors as $visitor) { |
| 36 | $this->addVisitor($visitor); |
| 37 | } |
| 38 | } |
| 39 | |
| 40 | public function addVisitor(NodeVisitorInterface $visitor): void |
| 41 | { |
| 42 | $this->visitors[$visitor->getPriority()][] = $visitor; |
| 43 | } |
| 44 | |
| 45 | /** |
| 46 | * Traverses a node and calls the registered visitors. |
| 47 | */ |
| 48 | public function traverse(Node $node): Node |
| 49 | { |
| 50 | ksort($this->visitors); |
| 51 | foreach ($this->visitors as $visitors) { |
| 52 | foreach ($visitors as $visitor) { |
| 53 | $node = $this->traverseForVisitor($visitor, $node); |
| 54 | } |
| 55 | } |
| 56 | |
| 57 | return $node; |
| 58 | } |
| 59 | |
| 60 | private function traverseForVisitor(NodeVisitorInterface $visitor, Node $node): ?Node |
| 61 | { |
| 62 | $node = $visitor->enterNode($node, $this->env); |
| 63 | |
| 64 | foreach ($node as $k => $n) { |
| 65 | if (null !== $m = $this->traverseForVisitor($visitor, $n)) { |
| 66 | if ($m !== $n) { |
| 67 | $node->setNode($k, $m); |
| 68 | } |
| 69 | } else { |
| 70 | $node->removeNode($k); |
| 71 | } |
| 72 | } |
| 73 | |
| 74 | return $visitor->leaveNode($node, $this->env); |
| 75 | } |
| 76 | } |