1: <?php
2:
3: 4: 5: 6:
7: class HTMLPurifier_AttrDef_Lang extends HTMLPurifier_AttrDef
8: {
9:
10: public function validate($string, $config, $context) {
11:
12: $string = trim($string);
13: if (!$string) return false;
14:
15: $subtags = explode('-', $string);
16: $num_subtags = count($subtags);
17:
18: if ($num_subtags == 0) return false;
19:
20:
21: $length = strlen($subtags[0]);
22: switch ($length) {
23: case 0:
24: return false;
25: case 1:
26: if (! ($subtags[0] == 'x' || $subtags[0] == 'i') ) {
27: return false;
28: }
29: break;
30: case 2:
31: case 3:
32: if (! ctype_alpha($subtags[0]) ) {
33: return false;
34: } elseif (! ctype_lower($subtags[0]) ) {
35: $subtags[0] = strtolower($subtags[0]);
36: }
37: break;
38: default:
39: return false;
40: }
41:
42: $new_string = $subtags[0];
43: if ($num_subtags == 1) return $new_string;
44:
45:
46: $length = strlen($subtags[1]);
47: if ($length == 0 || ($length == 1 && $subtags[1] != 'x') || $length > 8 || !ctype_alnum($subtags[1])) {
48: return $new_string;
49: }
50: if (!ctype_lower($subtags[1])) $subtags[1] = strtolower($subtags[1]);
51:
52: $new_string .= '-' . $subtags[1];
53: if ($num_subtags == 2) return $new_string;
54:
55:
56: for ($i = 2; $i < $num_subtags; $i++) {
57: $length = strlen($subtags[$i]);
58: if ($length == 0 || $length > 8 || !ctype_alnum($subtags[$i])) {
59: return $new_string;
60: }
61: if (!ctype_lower($subtags[$i])) {
62: $subtags[$i] = strtolower($subtags[$i]);
63: }
64: $new_string .= '-' . $subtags[$i];
65: }
66:
67: return $new_string;
68:
69: }
70:
71: }
72:
73:
74: