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
12namespace Twig\NodeVisitor;
13
14use Twig\Environment;
15use Twig\Node\Node;
16
17/**
18 * Used to make node visitors compatible with Twig 1.x and 2.x.
19 *
20 * @author Fabien Potencier <fabien@symfony.com>
21 */
22abstract class AbstractNodeVisitor implements NodeVisitorInterface
23{
24    final public function enterNode(\Twig_NodeInterface $node, Environment $env)
25    {
26        if (!$node instanceof Node) {
27            throw new \LogicException(sprintf('%s only supports \Twig\Node\Node instances.', __CLASS__));
28        }
29
30        return $this->doEnterNode($node, $env);
31    }
32
33    final public function leaveNode(\Twig_NodeInterface $node, Environment $env)
34    {
35        if (!$node instanceof Node) {
36            throw new \LogicException(sprintf('%s only supports \Twig\Node\Node instances.', __CLASS__));
37        }
38
39        return $this->doLeaveNode($node, $env);
40    }
41
42    /**
43     * Called before child nodes are visited.
44     *
45     * @return Node The modified node
46     */
47    abstract protected function doEnterNode(Node $node, Environment $env);
48
49    /**
50     * Called after child nodes are visited.
51     *
52     * @return Node|false The modified node or false if the node must be removed
53     */
54    abstract protected function doLeaveNode(Node $node, Environment $env);
55}
56
57class_alias('Twig\NodeVisitor\AbstractNodeVisitor', 'Twig_BaseNodeVisitor');
58