vendor/twig/twig/lib/Twig/NodeVisitor/Escaper.php

   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 /**
  13  * Twig_NodeVisitor_Escaper implements output escaping.
  14  *
  15  * @final
  16  *
  17  * @author Fabien Potencier <fabien@symfony.com>
  18  */
  19 class Twig_NodeVisitor_Escaper extends Twig_BaseNodeVisitor
  20 {
  21     protected $statusStack = array();
  22     protected $blocks = array();
  23     protected $safeAnalysis;
  24     protected $traverser;
  25     protected $defaultStrategy = false;
  26     protected $safeVars = array();
  27
  28     public function __construct()
  29     {
  30         $this->safeAnalysis = new Twig_NodeVisitor_SafeAnalysis();
  31     }
  32
  33     protected function doEnterNode(Twig_Node $node, Twig_Environment $env)
  34     {
  35         if ($node instanceof Twig_Node_Module) {
  36             if ($env->hasExtension('Twig_Extension_Escaper') && $defaultStrategy = $env->getExtension('Twig_Extension_Escaper')->getDefaultStrategy($node->getTemplateName())) {
  37                 $this->defaultStrategy = $defaultStrategy;
  38             }
  39             $this->safeVars = array();
  40             $this->blocks = array();
  41         } elseif ($node instanceof Twig_Node_AutoEscape) {
  42             $this->statusStack[] = $node->getAttribute('value');
  43         } elseif ($node instanceof Twig_Node_Block) {
  44             $this->statusStack[] = isset($this->blocks[$node->getAttribute('name')]) ? $this->blocks[$node->getAttribute('name')] : $this->needEscaping($env);
  45         } elseif ($node instanceof Twig_Node_Import) {
  46             $this->safeVars[] = $node->getNode('var')->getAttribute('name');
  47         }
  48
  49         return $node;
  50     }
  51
  52     protected function doLeaveNode(Twig_Node $node, Twig_Environment $env)
  53     {
  54         if ($node instanceof Twig_Node_Module) {
  55             $this->defaultStrategy = false;
  56             $this->safeVars = array();
  57             $this->blocks = array();
  58         } elseif ($node instanceof Twig_Node_Expression_Filter) {
  59             return $this->preEscapeFilterNode($node, $env);
  60         } elseif ($node instanceof Twig_Node_Print) {
  61             return $this->escapePrintNode($node, $env, $this->needEscaping($env));
  62         }
  63
  64         if ($node instanceof Twig_Node_AutoEscape || $node instanceof Twig_Node_Block) {
  65             array_pop($this->statusStack);
  66         } elseif ($node instanceof Twig_Node_BlockReference) {
  67             $this->blocks[$node->getAttribute('name')] = $this->needEscaping($env);
  68         }
  69
  70         return $node;
  71     }
  72
  73     protected function escapePrintNode(Twig_Node_Print $node, Twig_Environment $env, $type)
  74     {
  75         if (false === $type) {
  76             return $node;
  77         }
  78
  79         $expression = $node->getNode('expr');
  80
  81         if ($this->isSafeFor($type, $expression, $env)) {
  82             return $node;
  83         }
  84
  85         $class = get_class($node);
  86
  87         return new $class(
  88             $this->getEscaperFilter($type, $expression),
  89             $node->getTemplateLine()
  90         );
  91     }
  92
  93     protected function preEscapeFilterNode(Twig_Node_Expression_Filter $filter, Twig_Environment $env)
  94     {
  95         $name = $filter->getNode('filter')->getAttribute('value');
  96
  97         $type = $env->getFilter($name)->getPreEscape();
  98         if (null === $type) {
  99             return $filter;
 100         }
 101
 102         $node = $filter->getNode('node');
 103         if ($this->isSafeFor($type, $node, $env)) {
 104             return $filter;
 105         }
 106
 107         $filter->setNode('node', $this->getEscaperFilter($type, $node));
 108
 109         return $filter;
 110     }
 111
 112     protected function isSafeFor($type, Twig_NodeInterface $expression, $env)
 113     {
 114         $safe = $this->safeAnalysis->getSafe($expression);
 115
 116         if (null === $safe) {
 117             if (null === $this->traverser) {
 118                 $this->traverser = new Twig_NodeTraverser($env, array($this->safeAnalysis));
 119             }
 120
 121             $this->safeAnalysis->setSafeVars($this->safeVars);
 122
 123             $this->traverser->traverse($expression);
 124             $safe = $this->safeAnalysis->getSafe($expression);
 125         }
 126
 127         return in_array($type, $safe) || in_array('all', $safe);
 128     }
 129
 130     protected function needEscaping(Twig_Environment $env)
 131     {
 132         if (count($this->statusStack)) {
 133             return $this->statusStack[count($this->statusStack) - 1];
 134         }
 135
 136         return $this->defaultStrategy ? $this->defaultStrategy : false;
 137     }
 138
 139     protected function getEscaperFilter($type, Twig_NodeInterface $node)
 140     {
 141         $line = $node->getTemplateLine();
 142         $name = new Twig_Node_Expression_Constant('escape', $line);
 143         $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, $line)));
 144
 145         return new Twig_Node_Expression_Filter($node, $name, $args, $line);
 146     }
 147
 148     public function getPriority()
 149     {
 150         return 0;
 151     }
 152 }
 153
 154 class_alias('Twig_NodeVisitor_Escaper', 'Twig\NodeVisitor\EscaperNodeVisitor', false);