www.aleph1.co.uk Git - yaffs-website/blob - vendor/twig/twig/lib/Twig/NodeVisitor/SafeAnalysis.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  * @final
  14  */
  15 class Twig_NodeVisitor_SafeAnalysis extends Twig_BaseNodeVisitor
  16 {
  17     protected $data = array();
  18     protected $safeVars = array();
  19
  20     public function setSafeVars($safeVars)
  21     {
  22         $this->safeVars = $safeVars;
  23     }
  24
  25     public function getSafe(Twig_NodeInterface $node)
  26     {
  27         $hash = spl_object_hash($node);
  28         if (!isset($this->data[$hash])) {
  29             return;
  30         }
  31
  32         foreach ($this->data[$hash] as $bucket) {
  33             if ($bucket['key'] !== $node) {
  34                 continue;
  35             }
  36
  37             if (in_array('html_attr', $bucket['value'])) {
  38                 $bucket['value'][] = 'html';
  39             }
  40
  41             return $bucket['value'];
  42         }
  43     }
  44
  45     protected function setSafe(Twig_NodeInterface $node, array $safe)
  46     {
  47         $hash = spl_object_hash($node);
  48         if (isset($this->data[$hash])) {
  49             foreach ($this->data[$hash] as &$bucket) {
  50                 if ($bucket['key'] === $node) {
  51                     $bucket['value'] = $safe;
  52
  53                     return;
  54                 }
  55             }
  56         }
  57         $this->data[$hash][] = array(
  58             'key' => $node,
  59             'value' => $safe,
  60         );
  61     }
  62
  63     protected function doEnterNode(Twig_Node $node, Twig_Environment $env)
  64     {
  65         return $node;
  66     }
  67
  68     protected function doLeaveNode(Twig_Node $node, Twig_Environment $env)
  69     {
  70         if ($node instanceof Twig_Node_Expression_Constant) {
  71             // constants are marked safe for all
  72             $this->setSafe($node, array('all'));
  73         } elseif ($node instanceof Twig_Node_Expression_BlockReference) {
  74             // blocks are safe by definition
  75             $this->setSafe($node, array('all'));
  76         } elseif ($node instanceof Twig_Node_Expression_Parent) {
  77             // parent block is safe by definition
  78             $this->setSafe($node, array('all'));
  79         } elseif ($node instanceof Twig_Node_Expression_Conditional) {
  80             // intersect safeness of both operands
  81             $safe = $this->intersectSafe($this->getSafe($node->getNode('expr2')), $this->getSafe($node->getNode('expr3')));
  82             $this->setSafe($node, $safe);
  83         } elseif ($node instanceof Twig_Node_Expression_Filter) {
  84             // filter expression is safe when the filter is safe
  85             $name = $node->getNode('filter')->getAttribute('value');
  86             $args = $node->getNode('arguments');
  87             if (false !== $filter = $env->getFilter($name)) {
  88                 $safe = $filter->getSafe($args);
  89                 if (null === $safe) {
  90                     $safe = $this->intersectSafe($this->getSafe($node->getNode('node')), $filter->getPreservesSafety());
  91                 }
  92                 $this->setSafe($node, $safe);
  93             } else {
  94                 $this->setSafe($node, array());
  95             }
  96         } elseif ($node instanceof Twig_Node_Expression_Function) {
  97             // function expression is safe when the function is safe
  98             $name = $node->getAttribute('name');
  99             $args = $node->getNode('arguments');
 100             $function = $env->getFunction($name);
 101             if (false !== $function) {
 102                 $this->setSafe($node, $function->getSafe($args));
 103             } else {
 104                 $this->setSafe($node, array());
 105             }
 106         } elseif ($node instanceof Twig_Node_Expression_MethodCall) {
 107             if ($node->getAttribute('safe')) {
 108                 $this->setSafe($node, array('all'));
 109             } else {
 110                 $this->setSafe($node, array());
 111             }
 112         } elseif ($node instanceof Twig_Node_Expression_GetAttr && $node->getNode('node') instanceof Twig_Node_Expression_Name) {
 113             $name = $node->getNode('node')->getAttribute('name');
 114             // attributes on template instances are safe
 115             if ('_self' == $name || in_array($name, $this->safeVars)) {
 116                 $this->setSafe($node, array('all'));
 117             } else {
 118                 $this->setSafe($node, array());
 119             }
 120         } else {
 121             $this->setSafe($node, array());
 122         }
 123
 124         return $node;
 125     }
 126
 127     protected function intersectSafe(array $a = null, array $b = null)
 128     {
 129         if (null === $a || null === $b) {
 130             return array();
 131         }
 132
 133         if (in_array('all', $a)) {
 134             return $b;
 135         }
 136
 137         if (in_array('all', $b)) {
 138             return $a;
 139         }
 140
 141         return array_intersect($a, $b);
 142     }
 143
 144     public function getPriority()
 145     {
 146         return 0;
 147     }
 148 }
 149
 150 class_alias('Twig_NodeVisitor_SafeAnalysis', 'Twig\NodeVisitor\SafeAnalysisNodeVisitor', false);