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 */
10class 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}
72