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1: <?php
2:
3: /**
4: * Our in-house implementation of a parser.
5: *
6: * A pure PHP parser, DirectLex has absolutely no dependencies, making
7: * it a reasonably good default for PHP4. Written with efficiency in mind,
8: * it can be four times faster than HTMLPurifier_Lexer_PEARSax3, although it
9: * pales in comparison to HTMLPurifier_Lexer_DOMLex.
10: *
11: * @todo Reread XML spec and document differences.
12: */
13: class HTMLPurifier_Lexer_DirectLex extends HTMLPurifier_Lexer
14: {
15: /**
16: * @type bool
17: */
18: public $tracksLineNumbers = true;
19:
20: /**
21: * Whitespace characters for str(c)spn.
22: * @type string
23: */
24: protected $_whitespace = "\x20\x09\x0D\x0A";
25:
26: /**
27: * Callback function for script CDATA fudge
28: * @param array $matches, in form of array(opening tag, contents, closing tag)
29: * @return string
30: */
31: protected function scriptCallback($matches)
32: {
33: return $matches[1] . htmlspecialchars($matches[2], ENT_COMPAT, 'UTF-8') . $matches[3];
34: }
35:
36: /**
37: * @param String $html
38: * @param HTMLPurifier_Config $config
39: * @param HTMLPurifier_Context $context
40: * @return array|HTMLPurifier_Token[]
41: */
42: public function tokenizeHTML($html, $config, $context)
43: {
44: // special normalization for script tags without any armor
45: // our "armor" heurstic is a < sign any number of whitespaces after
46: // the first script tag
47: if ($config->get('HTML.Trusted')) {
48: $html = preg_replace_callback(
49: '#(<script[^>]*>)(\s*[^<].+?)(</script>)#si',
50: array($this, 'scriptCallback'),
51: $html
52: );
53: }
54:
55: $html = $this->normalize($html, $config, $context);
56:
57: $cursor = 0; // our location in the text
58: $inside_tag = false; // whether or not we're parsing the inside of a tag
59: $array = array(); // result array
60:
61: // This is also treated to mean maintain *column* numbers too
62: $maintain_line_numbers = $config->get('Core.MaintainLineNumbers');
63:
64: if ($maintain_line_numbers === null) {
65: // automatically determine line numbering by checking
66: // if error collection is on
67: $maintain_line_numbers = $config->get('Core.CollectErrors');
68: }
69:
70: if ($maintain_line_numbers) {
71: $current_line = 1;
72: $current_col = 0;
73: $length = strlen($html);
74: } else {
75: $current_line = false;
76: $current_col = false;
77: $length = false;
78: }
79: $context->register('CurrentLine', $current_line);
80: $context->register('CurrentCol', $current_col);
81: $nl = "\n";
82: // how often to manually recalculate. This will ALWAYS be right,
83: // but it's pretty wasteful. Set to 0 to turn off
84: $synchronize_interval = $config->get('Core.DirectLexLineNumberSyncInterval');
85:
86: $e = false;
87: if ($config->get('Core.CollectErrors')) {
88: $e =& $context->get('ErrorCollector');
89: }
90:
91: // for testing synchronization
92: $loops = 0;
93:
94: while (++$loops) {
95: // $cursor is either at the start of a token, or inside of
96: // a tag (i.e. there was a < immediately before it), as indicated
97: // by $inside_tag
98:
99: if ($maintain_line_numbers) {
100: // $rcursor, however, is always at the start of a token.
101: $rcursor = $cursor - (int)$inside_tag;
102:
103: // Column number is cheap, so we calculate it every round.
104: // We're interested at the *end* of the newline string, so
105: // we need to add strlen($nl) == 1 to $nl_pos before subtracting it
106: // from our "rcursor" position.
107: $nl_pos = strrpos($html, $nl, $rcursor - $length);
108: $current_col = $rcursor - (is_bool($nl_pos) ? 0 : $nl_pos + 1);
109:
110: // recalculate lines
111: if ($synchronize_interval && // synchronization is on
112: $cursor > 0 && // cursor is further than zero
113: $loops % $synchronize_interval === 0) { // time to synchronize!
114: $current_line = 1 + $this->substrCount($html, $nl, 0, $cursor);
115: }
116: }
117:
118: $position_next_lt = strpos($html, '<', $cursor);
119: $position_next_gt = strpos($html, '>', $cursor);
120:
121: // triggers on "<b>asdf</b>" but not "asdf <b></b>"
122: // special case to set up context
123: if ($position_next_lt === $cursor) {
124: $inside_tag = true;
125: $cursor++;
126: }
127:
128: if (!$inside_tag && $position_next_lt !== false) {
129: // We are not inside tag and there still is another tag to parse
130: $token = new
131: HTMLPurifier_Token_Text(
132: $this->parseText(
133: substr(
134: $html,
135: $cursor,
136: $position_next_lt - $cursor
137: ), $config
138: )
139: );
140: if ($maintain_line_numbers) {
141: $token->rawPosition($current_line, $current_col);
142: $current_line += $this->substrCount($html, $nl, $cursor, $position_next_lt - $cursor);
143: }
144: $array[] = $token;
145: $cursor = $position_next_lt + 1;
146: $inside_tag = true;
147: continue;
148: } elseif (!$inside_tag) {
149: // We are not inside tag but there are no more tags
150: // If we're already at the end, break
151: if ($cursor === strlen($html)) {
152: break;
153: }
154: // Create Text of rest of string
155: $token = new
156: HTMLPurifier_Token_Text(
157: $this->parseText(
158: substr(
159: $html,
160: $cursor
161: ), $config
162: )
163: );
164: if ($maintain_line_numbers) {
165: $token->rawPosition($current_line, $current_col);
166: }
167: $array[] = $token;
168: break;
169: } elseif ($inside_tag && $position_next_gt !== false) {
170: // We are in tag and it is well formed
171: // Grab the internals of the tag
172: $strlen_segment = $position_next_gt - $cursor;
173:
174: if ($strlen_segment < 1) {
175: // there's nothing to process!
176: $token = new HTMLPurifier_Token_Text('<');
177: $cursor++;
178: continue;
179: }
180:
181: $segment = substr($html, $cursor, $strlen_segment);
182:
183: if ($segment === false) {
184: // somehow, we attempted to access beyond the end of
185: // the string, defense-in-depth, reported by Nate Abele
186: break;
187: }
188:
189: // Check if it's a comment
190: if (substr($segment, 0, 3) === '!--') {
191: // re-determine segment length, looking for -->
192: $position_comment_end = strpos($html, '-->', $cursor);
193: if ($position_comment_end === false) {
194: // uh oh, we have a comment that extends to
195: // infinity. Can't be helped: set comment
196: // end position to end of string
197: if ($e) {
198: $e->send(E_WARNING, 'Lexer: Unclosed comment');
199: }
200: $position_comment_end = strlen($html);
201: $end = true;
202: } else {
203: $end = false;
204: }
205: $strlen_segment = $position_comment_end - $cursor;
206: $segment = substr($html, $cursor, $strlen_segment);
207: $token = new
208: HTMLPurifier_Token_Comment(
209: substr(
210: $segment,
211: 3,
212: $strlen_segment - 3
213: )
214: );
215: if ($maintain_line_numbers) {
216: $token->rawPosition($current_line, $current_col);
217: $current_line += $this->substrCount($html, $nl, $cursor, $strlen_segment);
218: }
219: $array[] = $token;
220: $cursor = $end ? $position_comment_end : $position_comment_end + 3;
221: $inside_tag = false;
222: continue;
223: }
224:
225: // Check if it's an end tag
226: $is_end_tag = (strpos($segment, '/') === 0);
227: if ($is_end_tag) {
228: $type = substr($segment, 1);
229: $token = new HTMLPurifier_Token_End($type);
230: if ($maintain_line_numbers) {
231: $token->rawPosition($current_line, $current_col);
232: $current_line += $this->substrCount($html, $nl, $cursor, $position_next_gt - $cursor);
233: }
234: $array[] = $token;
235: $inside_tag = false;
236: $cursor = $position_next_gt + 1;
237: continue;
238: }
239:
240: // Check leading character is alnum, if not, we may
241: // have accidently grabbed an emoticon. Translate into
242: // text and go our merry way
243: if (!ctype_alpha($segment[0])) {
244: // XML: $segment[0] !== '_' && $segment[0] !== ':'
245: if ($e) {
246: $e->send(E_NOTICE, 'Lexer: Unescaped lt');
247: }
248: $token = new HTMLPurifier_Token_Text('<');
249: if ($maintain_line_numbers) {
250: $token->rawPosition($current_line, $current_col);
251: $current_line += $this->substrCount($html, $nl, $cursor, $position_next_gt - $cursor);
252: }
253: $array[] = $token;
254: $inside_tag = false;
255: continue;
256: }
257:
258: // Check if it is explicitly self closing, if so, remove
259: // trailing slash. Remember, we could have a tag like <br>, so
260: // any later token processing scripts must convert improperly
261: // classified EmptyTags from StartTags.
262: $is_self_closing = (strrpos($segment, '/') === $strlen_segment - 1);
263: if ($is_self_closing) {
264: $strlen_segment--;
265: $segment = substr($segment, 0, $strlen_segment);
266: }
267:
268: // Check if there are any attributes
269: $position_first_space = strcspn($segment, $this->_whitespace);
270:
271: if ($position_first_space >= $strlen_segment) {
272: if ($is_self_closing) {
273: $token = new HTMLPurifier_Token_Empty($segment);
274: } else {
275: $token = new HTMLPurifier_Token_Start($segment);
276: }
277: if ($maintain_line_numbers) {
278: $token->rawPosition($current_line, $current_col);
279: $current_line += $this->substrCount($html, $nl, $cursor, $position_next_gt - $cursor);
280: }
281: $array[] = $token;
282: $inside_tag = false;
283: $cursor = $position_next_gt + 1;
284: continue;
285: }
286:
287: // Grab out all the data
288: $type = substr($segment, 0, $position_first_space);
289: $attribute_string =
290: trim(
291: substr(
292: $segment,
293: $position_first_space
294: )
295: );
296: if ($attribute_string) {
297: $attr = $this->parseAttributeString(
298: $attribute_string,
299: $config,
300: $context
301: );
302: } else {
303: $attr = array();
304: }
305:
306: if ($is_self_closing) {
307: $token = new HTMLPurifier_Token_Empty($type, $attr);
308: } else {
309: $token = new HTMLPurifier_Token_Start($type, $attr);
310: }
311: if ($maintain_line_numbers) {
312: $token->rawPosition($current_line, $current_col);
313: $current_line += $this->substrCount($html, $nl, $cursor, $position_next_gt - $cursor);
314: }
315: $array[] = $token;
316: $cursor = $position_next_gt + 1;
317: $inside_tag = false;
318: continue;
319: } else {
320: // inside tag, but there's no ending > sign
321: if ($e) {
322: $e->send(E_WARNING, 'Lexer: Missing gt');
323: }
324: $token = new
325: HTMLPurifier_Token_Text(
326: '<' .
327: $this->parseText(
328: substr($html, $cursor), $config
329: )
330: );
331: if ($maintain_line_numbers) {
332: $token->rawPosition($current_line, $current_col);
333: }
334: // no cursor scroll? Hmm...
335: $array[] = $token;
336: break;
337: }
338: break;
339: }
340:
341: $context->destroy('CurrentLine');
342: $context->destroy('CurrentCol');
343: return $array;
344: }
345:
346: /**
347: * PHP 5.0.x compatible substr_count that implements offset and length
348: * @param string $haystack
349: * @param string $needle
350: * @param int $offset
351: * @param int $length
352: * @return int
353: */
354: protected function substrCount($haystack, $needle, $offset, $length)
355: {
356: static $oldVersion;
357: if ($oldVersion === null) {
358: $oldVersion = version_compare(PHP_VERSION, '5.1', '<');
359: }
360: if ($oldVersion) {
361: $haystack = substr($haystack, $offset, $length);
362: return substr_count($haystack, $needle);
363: } else {
364: return substr_count($haystack, $needle, $offset, $length);
365: }
366: }
367:
368: /**
369: * Takes the inside of an HTML tag and makes an assoc array of attributes.
370: *
371: * @param string $string Inside of tag excluding name.
372: * @param HTMLPurifier_Config $config
373: * @param HTMLPurifier_Context $context
374: * @return array Assoc array of attributes.
375: */
376: public function parseAttributeString($string, $config, $context)
377: {
378: $string = (string)$string; // quick typecast
379:
380: if ($string == '') {
381: return array();
382: } // no attributes
383:
384: $e = false;
385: if ($config->get('Core.CollectErrors')) {
386: $e =& $context->get('ErrorCollector');
387: }
388:
389: // let's see if we can abort as quickly as possible
390: // one equal sign, no spaces => one attribute
391: $num_equal = substr_count($string, '=');
392: $has_space = strpos($string, ' ');
393: if ($num_equal === 0 && !$has_space) {
394: // bool attribute
395: return array($string => $string);
396: } elseif ($num_equal === 1 && !$has_space) {
397: // only one attribute
398: list($key, $quoted_value) = explode('=', $string);
399: $quoted_value = trim($quoted_value);
400: if (!$key) {
401: if ($e) {
402: $e->send(E_ERROR, 'Lexer: Missing attribute key');
403: }
404: return array();
405: }
406: if (!$quoted_value) {
407: return array($key => '');
408: }
409: $first_char = @$quoted_value[0];
410: $last_char = @$quoted_value[strlen($quoted_value) - 1];
411:
412: $same_quote = ($first_char == $last_char);
413: $open_quote = ($first_char == '"' || $first_char == "'");
414:
415: if ($same_quote && $open_quote) {
416: // well behaved
417: $value = substr($quoted_value, 1, strlen($quoted_value) - 2);
418: } else {
419: // not well behaved
420: if ($open_quote) {
421: if ($e) {
422: $e->send(E_ERROR, 'Lexer: Missing end quote');
423: }
424: $value = substr($quoted_value, 1);
425: } else {
426: $value = $quoted_value;
427: }
428: }
429: if ($value === false) {
430: $value = '';
431: }
432: return array($key => $this->parseAttr($value, $config));
433: }
434:
435: // setup loop environment
436: $array = array(); // return assoc array of attributes
437: $cursor = 0; // current position in string (moves forward)
438: $size = strlen($string); // size of the string (stays the same)
439:
440: // if we have unquoted attributes, the parser expects a terminating
441: // space, so let's guarantee that there's always a terminating space.
442: $string .= ' ';
443:
444: $old_cursor = -1;
445: while ($cursor < $size) {
446: if ($old_cursor >= $cursor) {
447: throw new Exception("Infinite loop detected");
448: }
449: $old_cursor = $cursor;
450:
451: $cursor += ($value = strspn($string, $this->_whitespace, $cursor));
452: // grab the key
453:
454: $key_begin = $cursor; //we're currently at the start of the key
455:
456: // scroll past all characters that are the key (not whitespace or =)
457: $cursor += strcspn($string, $this->_whitespace . '=', $cursor);
458:
459: $key_end = $cursor; // now at the end of the key
460:
461: $key = substr($string, $key_begin, $key_end - $key_begin);
462:
463: if (!$key) {
464: if ($e) {
465: $e->send(E_ERROR, 'Lexer: Missing attribute key');
466: }
467: $cursor += 1 + strcspn($string, $this->_whitespace, $cursor + 1); // prevent infinite loop
468: continue; // empty key
469: }
470:
471: // scroll past all whitespace
472: $cursor += strspn($string, $this->_whitespace, $cursor);
473:
474: if ($cursor >= $size) {
475: $array[$key] = $key;
476: break;
477: }
478:
479: // if the next character is an equal sign, we've got a regular
480: // pair, otherwise, it's a bool attribute
481: $first_char = @$string[$cursor];
482:
483: if ($first_char == '=') {
484: // key="value"
485:
486: $cursor++;
487: $cursor += strspn($string, $this->_whitespace, $cursor);
488:
489: if ($cursor === false) {
490: $array[$key] = '';
491: break;
492: }
493:
494: // we might be in front of a quote right now
495:
496: $char = @$string[$cursor];
497:
498: if ($char == '"' || $char == "'") {
499: // it's quoted, end bound is $char
500: $cursor++;
501: $value_begin = $cursor;
502: $cursor = strpos($string, $char, $cursor);
503: $value_end = $cursor;
504: } else {
505: // it's not quoted, end bound is whitespace
506: $value_begin = $cursor;
507: $cursor += strcspn($string, $this->_whitespace, $cursor);
508: $value_end = $cursor;
509: }
510:
511: // we reached a premature end
512: if ($cursor === false) {
513: $cursor = $size;
514: $value_end = $cursor;
515: }
516:
517: $value = substr($string, $value_begin, $value_end - $value_begin);
518: if ($value === false) {
519: $value = '';
520: }
521: $array[$key] = $this->parseAttr($value, $config);
522: $cursor++;
523: } else {
524: // boolattr
525: if ($key !== '') {
526: $array[$key] = $key;
527: } else {
528: // purely theoretical
529: if ($e) {
530: $e->send(E_ERROR, 'Lexer: Missing attribute key');
531: }
532: }
533: }
534: }
535: return $array;
536: }
537: }
538:
539: // vim: et sw=4 sts=4
540:
API documentation generated by ApiGen v7.0.0-alpha.6