1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
|
<?php
/*
* This file is part of Twig.
*
* (c) 2009 Fabien Potencier
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
/**
* Twig_NodeVisitor_Escaper implements output escaping.
*
* @author Fabien Potencier <fabien@symfony.com>
*/
class Twig_NodeVisitor_Escaper implements Twig_NodeVisitorInterface
{
protected $statusStack = array();
protected $blocks = array();
protected $safeAnalysis;
protected $traverser;
protected $defaultStrategy = false;
protected $safeVars = array();
public function __construct()
{
$this->safeAnalysis = new Twig_NodeVisitor_SafeAnalysis();
}
/**
* Called before child nodes are visited.
*
* @param Twig_NodeInterface $node The node to visit
* @param Twig_Environment $env The Twig environment instance
*
* @return Twig_NodeInterface The modified node
*/
public function enterNode(Twig_NodeInterface $node, Twig_Environment $env)
{
if ($node instanceof Twig_Node_Module) {
if ($env->hasExtension('escaper') && $defaultStrategy = $env->getExtension('escaper')->getDefaultStrategy($node->getAttribute('filename'))) {
$this->defaultStrategy = $defaultStrategy;
}
$this->safeVars = array();
} elseif ($node instanceof Twig_Node_AutoEscape) {
$this->statusStack[] = $node->getAttribute('value');
} elseif ($node instanceof Twig_Node_Block) {
$this->statusStack[] = isset($this->blocks[$node->getAttribute('name')]) ? $this->blocks[$node->getAttribute('name')] : $this->needEscaping($env);
} elseif ($node instanceof Twig_Node_Import) {
$this->safeVars[] = $node->getNode('var')->getAttribute('name');
}
return $node;
}
/**
* Called after child nodes are visited.
*
* @param Twig_NodeInterface $node The node to visit
* @param Twig_Environment $env The Twig environment instance
*
* @return Twig_NodeInterface The modified node
*/
public function leaveNode(Twig_NodeInterface $node, Twig_Environment $env)
{
if ($node instanceof Twig_Node_Module) {
$this->defaultStrategy = false;
$this->safeVars = array();
} elseif ($node instanceof Twig_Node_Expression_Filter) {
return $this->preEscapeFilterNode($node, $env);
} elseif ($node instanceof Twig_Node_Print) {
return $this->escapePrintNode($node, $env, $this->needEscaping($env));
}
if ($node instanceof Twig_Node_AutoEscape || $node instanceof Twig_Node_Block) {
array_pop($this->statusStack);
} elseif ($node instanceof Twig_Node_BlockReference) {
$this->blocks[$node->getAttribute('name')] = $this->needEscaping($env);
}
return $node;
}
protected function escapePrintNode(Twig_Node_Print $node, Twig_Environment $env, $type)
{
if (false === $type) {
return $node;
}
$expression = $node->getNode('expr');
if ($this->isSafeFor($type, $expression, $env)) {
return $node;
}
$class = get_class($node);
return new $class(
$this->getEscaperFilter($type, $expression),
$node->getLine()
);
}
protected function preEscapeFilterNode(Twig_Node_Expression_Filter $filter, Twig_Environment $env)
{
$name = $filter->getNode('filter')->getAttribute('value');
$type = $env->getFilter($name)->getPreEscape();
if (null === $type) {
return $filter;
}
$node = $filter->getNode('node');
if ($this->isSafeFor($type, $node, $env)) {
return $filter;
}
$filter->setNode('node', $this->getEscaperFilter($type, $node));
return $filter;
}
protected function isSafeFor($type, Twig_NodeInterface $expression, $env)
{
$safe = $this->safeAnalysis->getSafe($expression);
if (null === $safe) {
if (null === $this->traverser) {
$this->traverser = new Twig_NodeTraverser($env, array($this->safeAnalysis));
}
$this->safeAnalysis->setSafeVars($this->safeVars);
$this->traverser->traverse($expression);
$safe = $this->safeAnalysis->getSafe($expression);
}
return in_array($type, $safe) || in_array('all', $safe);
}
protected function needEscaping(Twig_Environment $env)
{
if (count($this->statusStack)) {
return $this->statusStack[count($this->statusStack) - 1];
}
return $this->defaultStrategy ? $this->defaultStrategy : false;
}
protected function getEscaperFilter($type, Twig_NodeInterface $node)
{
$line = $node->getLine();
$name = new Twig_Node_Expression_Constant('escape', $line);
$args = new Twig_Node(array(new Twig_Node_Expression_Constant((string) $type, $line), new Twig_Node_Expression_Constant(null, $line), new Twig_Node_Expression_Constant(true, $line)));
return new Twig_Node_Expression_Filter($node, $name, $args, $line);
}
/**
* {@inheritdoc}
*/
public function getPriority()
{
return 0;
}
}
|
