library/HTMLPurifier/Arborize.php

   1 <?php
   2
   3 /**
   4  * Converts a stream of HTMLPurifier_Token into an HTMLPurifier_Node,
   5  * and back again.
   6  *
   7  * @note This transformation is not an equivalence.  We mutate the input
   8  * token stream to make it so; see all [MUT] markers in code.
   9  */
  10 class HTMLPurifier_Arborize
  11 {
  12     public static function arborize($tokens, $config, $context) {
  13         $definition = $config->getHTMLDefinition();
  14         $parent = new HTMLPurifier_Token_Start($definition->info_parent);
  15         $stack = array($parent->toNode());
  16         foreach ($tokens as $token) {
  17             $token->skip = null; // [MUT]
  18             $token->carryover = null; // [MUT]
  19             if ($token instanceof HTMLPurifier_Token_End) {
  20                 $token->start = null; // [MUT]
  21                 $r = array_pop($stack);
  22                 //assert($r->name === $token->name);
  23                 //assert(empty($token->attr));
  24                 $r->endCol = $token->col;
  25                 $r->endLine = $token->line;
  26                 $r->endArmor = $token->armor;
  27                 continue;
  28             }
  29             $node = $token->toNode();
  30             $stack[count($stack)-1]->children[] = $node;
  31             if ($token instanceof HTMLPurifier_Token_Start) {
  32                 $stack[] = $node;
  33             }
  34         }
  35         //assert(count($stack) == 1);
  36         return $stack[0];
  37     }
  38
  39     public static function flatten($node, $config, $context) {
  40         $level = 0;
  41         $nodes = array($level => new HTMLPurifier_Queue(array($node)));
  42         $closingTokens = array();
  43         $tokens = array();
  44         do {
  45             while (!$nodes[$level]->isEmpty()) {
  46                 $node = $nodes[$level]->shift(); // FIFO
  47                 list($start, $end) = $node->toTokenPair();
  48                 if ($level > 0) {
  49                     $tokens[] = $start;
  50                 }
  51                 if ($end !== NULL) {
  52                     $closingTokens[$level][] = $end;
  53                 }
  54                 if ($node instanceof HTMLPurifier_Node_Element) {
  55                     $level++;
  56                     $nodes[$level] = new HTMLPurifier_Queue();
  57                     foreach ($node->children as $childNode) {
  58                         $nodes[$level]->push($childNode);
  59                     }
  60                 }
  61             }
  62             $level--;
  63             if ($level && isset($closingTokens[$level])) {
  64                 while ($token = array_pop($closingTokens[$level])) {
  65                     $tokens[] = $token;
  66                 }
  67             }
  68         } while ($level > 0);
  69         return $tokens;
  70     }
  71 }