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1 <?php 2 /** 3 * HTML API: WP_HTML_Tag_Processor class 4 * 5 * Scans through an HTML document to find specific tags, then 6 * transforms those tags by adding, removing, or updating the 7 * values of the HTML attributes within that tag (opener). 8 * 9 * Does not fully parse HTML or _recurse_ into the HTML structure 10 * Instead this scans linearly through a document and only parses 11 * the HTML tag openers. 12 * 13 * ### Possible future direction for this module 14 * 15 * - Prune the whitespace when removing classes/attributes: e.g. "a b c" -> "c" not " c". 16 * This would increase the size of the changes for some operations but leave more 17 * natural-looking output HTML. 18 * 19 * @package WordPress 20 * @subpackage HTML-API 21 * @since 6.2.0 22 */ 23 24 /** 25 * Core class used to modify attributes in an HTML document for tags matching a query. 26 * 27 * ## Usage 28 * 29 * Use of this class requires three steps: 30 * 31 * 1. Create a new class instance with your input HTML document. 32 * 2. Find the tag(s) you are looking for. 33 * 3. Request changes to the attributes in those tag(s). 34 * 35 * Example: 36 * 37 * $tags = new WP_HTML_Tag_Processor( $html ); 38 * if ( $tags->next_tag( 'option' ) ) { 39 * $tags->set_attribute( 'selected', true ); 40 * } 41 * 42 * ### Finding tags 43 * 44 * The `next_tag()` function moves the internal cursor through 45 * your input HTML document until it finds a tag meeting any of 46 * the supplied restrictions in the optional query argument. If 47 * no argument is provided then it will find the next HTML tag, 48 * regardless of what kind it is. 49 * 50 * If you want to _find whatever the next tag is_: 51 * 52 * $tags->next_tag(); 53 * 54 * | Goal | Query | 55 * |-----------------------------------------------------------|---------------------------------------------------------------------------------| 56 * | Find any tag. | `$tags->next_tag();` | 57 * | Find next image tag. | `$tags->next_tag( array( 'tag_name' => 'img' ) );` | 58 * | Find next image tag (without passing the array). | `$tags->next_tag( 'img' );` | 59 * | Find next tag containing the `fullwidth` CSS class. | `$tags->next_tag( array( 'class_name' => 'fullwidth' ) );` | 60 * | Find next image tag containing the `fullwidth` CSS class. | `$tags->next_tag( array( 'tag_name' => 'img', 'class_name' => 'fullwidth' ) );` | 61 * 62 * If a tag was found meeting your criteria then `next_tag()` 63 * will return `true` and you can proceed to modify it. If it 64 * returns `false`, however, it failed to find the tag and 65 * moved the cursor to the end of the file. 66 * 67 * Once the cursor reaches the end of the file the processor 68 * is done and if you want to reach an earlier tag you will 69 * need to recreate the processor and start over, as it's 70 * unable to back up or move in reverse. 71 * 72 * See the section on bookmarks for an exception to this 73 * no-backing-up rule. 74 * 75 * #### Custom queries 76 * 77 * Sometimes it's necessary to further inspect an HTML tag than 78 * the query syntax here permits. In these cases one may further 79 * inspect the search results using the read-only functions 80 * provided by the processor or external state or variables. 81 * 82 * Example: 83 * 84 * // Paint up to the first five DIV or SPAN tags marked with the "jazzy" style. 85 * $remaining_count = 5; 86 * while ( $remaining_count > 0 && $tags->next_tag() ) { 87 * if ( 88 * ( 'DIV' === $tags->get_tag() || 'SPAN' === $tags->get_tag() ) && 89 * 'jazzy' === $tags->get_attribute( 'data-style' ) 90 * ) { 91 * $tags->add_class( 'theme-style-everest-jazz' ); 92 * $remaining_count--; 93 * } 94 * } 95 * 96 * `get_attribute()` will return `null` if the attribute wasn't present 97 * on the tag when it was called. It may return `""` (the empty string) 98 * in cases where the attribute was present but its value was empty. 99 * For boolean attributes, those whose name is present but no value is 100 * given, it will return `true` (the only way to set `false` for an 101 * attribute is to remove it). 102 * 103 * #### When matching fails 104 * 105 * When `next_tag()` returns `false` it could mean different things: 106 * 107 * - The requested tag wasn't found in the input document. 108 * - The input document ended in the middle of an HTML syntax element. 109 * 110 * When a document ends in the middle of a syntax element it will pause 111 * the processor. This is to make it possible in the future to extend the 112 * input document and proceed - an important requirement for chunked 113 * streaming parsing of a document. 114 * 115 * Example: 116 * 117 * $processor = new WP_HTML_Tag_Processor( 'This <div is="a" partial="token' ); 118 * false === $processor->next_tag(); 119 * 120 * If a special element (see next section) is encountered but no closing tag 121 * is found it will count as an incomplete tag. The parser will pause as if 122 * the opening tag were incomplete. 123 * 124 * Example: 125 * 126 * $processor = new WP_HTML_Tag_Processor( '<style>// there could be more styling to come' ); 127 * false === $processor->next_tag(); 128 * 129 * $processor = new WP_HTML_Tag_Processor( '<style>// this is everything</style><div>' ); 130 * true === $processor->next_tag( 'DIV' ); 131 * 132 * #### Special self-contained elements 133 * 134 * Some HTML elements are handled in a special way; their start and end tags 135 * act like a void tag. These are special because their contents can't contain 136 * HTML markup. Everything inside these elements is handled in a special way 137 * and content that _appears_ like HTML tags inside of them isn't. There can 138 * be no nesting in these elements. 139 * 140 * In the following list, "raw text" means that all of the content in the HTML 141 * until the matching closing tag is treated verbatim without any replacements 142 * and without any parsing. 143 * 144 * - IFRAME allows no content but requires a closing tag. 145 * - NOEMBED (deprecated) content is raw text. 146 * - NOFRAMES (deprecated) content is raw text. 147 * - SCRIPT content is plaintext apart from legacy rules allowing `</script>` inside an HTML comment. 148 * - STYLE content is raw text. 149 * - TITLE content is plain text but character references are decoded. 150 * - TEXTAREA content is plain text but character references are decoded. 151 * - XMP (deprecated) content is raw text. 152 * 153 * ### Modifying HTML attributes for a found tag 154 * 155 * Once you've found the start of an opening tag you can modify 156 * any number of the attributes on that tag. You can set a new 157 * value for an attribute, remove the entire attribute, or do 158 * nothing and move on to the next opening tag. 159 * 160 * Example: 161 * 162 * if ( $tags->next_tag( array( 'class_name' => 'wp-group-block' ) ) ) { 163 * $tags->set_attribute( 'title', 'This groups the contained content.' ); 164 * $tags->remove_attribute( 'data-test-id' ); 165 * } 166 * 167 * If `set_attribute()` is called for an existing attribute it will 168 * overwrite the existing value. Similarly, calling `remove_attribute()` 169 * for a non-existing attribute has no effect on the document. Both 170 * of these methods are safe to call without knowing if a given attribute 171 * exists beforehand. 172 * 173 * ### Modifying CSS classes for a found tag 174 * 175 * The tag processor treats the `class` attribute as a special case. 176 * Because it's a common operation to add or remove CSS classes, this 177 * interface adds helper methods to make that easier. 178 * 179 * As with attribute values, adding or removing CSS classes is a safe 180 * operation that doesn't require checking if the attribute or class 181 * exists before making changes. If removing the only class then the 182 * entire `class` attribute will be removed. 183 * 184 * Example: 185 * 186 * // from `<span>Yippee!</span>` 187 * // to `<span class="is-active">Yippee!</span>` 188 * $tags->add_class( 'is-active' ); 189 * 190 * // from `<span class="excited">Yippee!</span>` 191 * // to `<span class="excited is-active">Yippee!</span>` 192 * $tags->add_class( 'is-active' ); 193 * 194 * // from `<span class="is-active heavy-accent">Yippee!</span>` 195 * // to `<span class="is-active heavy-accent">Yippee!</span>` 196 * $tags->add_class( 'is-active' ); 197 * 198 * // from `<input type="text" class="is-active rugby not-disabled" length="24">` 199 * // to `<input type="text" class="is-active not-disabled" length="24"> 200 * $tags->remove_class( 'rugby' ); 201 * 202 * // from `<input type="text" class="rugby" length="24">` 203 * // to `<input type="text" length="24"> 204 * $tags->remove_class( 'rugby' ); 205 * 206 * // from `<input type="text" length="24">` 207 * // to `<input type="text" length="24"> 208 * $tags->remove_class( 'rugby' ); 209 * 210 * When class changes are enqueued but a direct change to `class` is made via 211 * `set_attribute` then the changes to `set_attribute` (or `remove_attribute`) 212 * will take precedence over those made through `add_class` and `remove_class`. 213 * 214 * ### Bookmarks 215 * 216 * While scanning through the input HTML document it's possible to set 217 * a named bookmark when a particular tag is found. Later on, after 218 * continuing to scan other tags, it's possible to `seek` to one of 219 * the set bookmarks and then proceed again from that point forward. 220 * 221 * Because bookmarks create processing overhead one should avoid 222 * creating too many of them. As a rule, create only bookmarks 223 * of known string literal names; avoid creating "mark_{$index}" 224 * and so on. It's fine from a performance standpoint to create a 225 * bookmark and update it frequently, such as within a loop. 226 * 227 * $total_todos = 0; 228 * while ( $p->next_tag( array( 'tag_name' => 'UL', 'class_name' => 'todo' ) ) ) { 229 * $p->set_bookmark( 'list-start' ); 230 * while ( $p->next_tag( array( 'tag_closers' => 'visit' ) ) ) { 231 * if ( 'UL' === $p->get_tag() && $p->is_tag_closer() ) { 232 * $p->set_bookmark( 'list-end' ); 233 * $p->seek( 'list-start' ); 234 * $p->set_attribute( 'data-contained-todos', (string) $total_todos ); 235 * $total_todos = 0; 236 * $p->seek( 'list-end' ); 237 * break; 238 * } 239 * 240 * if ( 'LI' === $p->get_tag() && ! $p->is_tag_closer() ) { 241 * $total_todos++; 242 * } 243 * } 244 * } 245 * 246 * ## Tokens and finer-grained processing. 247 * 248 * It's possible to scan through every lexical token in the 249 * HTML document using the `next_token()` function. This 250 * alternative form takes no argument and provides no built-in 251 * query syntax. 252 * 253 * Example: 254 * 255 * $title = '(untitled)'; 256 * $text = ''; 257 * while ( $processor->next_token() ) { 258 * switch ( $processor->get_token_name() ) { 259 * case '#text': 260 * $text .= $processor->get_modifiable_text(); 261 * break; 262 * 263 * case 'BR': 264 * $text .= "\n"; 265 * break; 266 * 267 * case 'TITLE': 268 * $title = $processor->get_modifiable_text(); 269 * break; 270 * } 271 * } 272 * return trim( "# {$title}\n\n{$text}" ); 273 * 274 * ### Tokens and _modifiable text_. 275 * 276 * #### Special "atomic" HTML elements. 277 * 278 * Not all HTML elements are able to contain other elements inside of them. 279 * For instance, the contents inside a TITLE element are plaintext (except 280 * that character references like & will be decoded). This means that 281 * if the string `<img>` appears inside a TITLE element, then it's not an 282 * image tag, but rather it's text describing an image tag. Likewise, the 283 * contents of a SCRIPT or STYLE element are handled entirely separately in 284 * a browser than the contents of other elements because they represent a 285 * different language than HTML. 286 * 287 * For these elements the Tag Processor treats the entire sequence as one, 288 * from the opening tag, including its contents, through its closing tag. 289 * This means that it's not possible to match the closing tag for a 290 * SCRIPT element unless it's unexpected; the Tag Processor already matched 291 * it when it found the opening tag. 292 * 293 * The inner contents of these elements are that element's _modifiable text_. 294 * 295 * The special elements are: 296 * - `SCRIPT` whose contents are treated as raw plaintext but supports a legacy 297 * style of including JavaScript inside of HTML comments to avoid accidentally 298 * closing the SCRIPT from inside a JavaScript string. E.g. `console.log( '</script>' )`. 299 * - `TITLE` and `TEXTAREA` whose contents are treated as plaintext and then any 300 * character references are decoded. E.g. `1 < 2 < 3` becomes `1 < 2 < 3`. 301 * - `IFRAME`, `NOEMBED`, `NOFRAMES`, `STYLE`, `XMP` whose contents are treated as 302 * raw plaintext and left as-is. E.g. `1 < 2 < 3` remains `1 < 2 < 3`. 303 * 304 * #### Other tokens with modifiable text. 305 * 306 * There are also non-elements which are void/self-closing in nature and contain 307 * modifiable text that is part of that individual syntax token itself. 308 * 309 * - `#text` nodes, whose entire token _is_ the modifiable text. 310 * - HTML comments and tokens that become comments due to some syntax error. The 311 * text for these tokens is the portion of the comment inside of the syntax. 312 * E.g. for `<!-- comment -->` the text is `" comment "` (note the spaces are included). 313 * - `CDATA` sections, whose text is the content inside of the section itself. E.g. for 314 * `<![CDATA[some content]]>` the text is `"some content"` (with restrictions [1]). 315 * - "Funky comments," which are a special case of invalid closing tags whose name is 316 * invalid. The text for these nodes is the text that a browser would transform into 317 * an HTML comment when parsing. E.g. for `</%post_author>` the text is `%post_author`. 318 * - `DOCTYPE` declarations like `<DOCTYPE html>` which have no closing tag. 319 * - Processing instruction nodes like `<?wp __( "Like" ); ?>` (with restrictions [2]). 320 * - The empty end tag `</>` which is ignored in the browser and DOM. 321 * 322 * [1]: There are no CDATA sections in HTML. When encountering `<![CDATA[`, everything 323 * until the next `>` becomes a bogus HTML comment, meaning there can be no CDATA 324 * section in an HTML document containing `>`. The Tag Processor will first find 325 * all valid and bogus HTML comments, and then if the comment _would_ have been a 326 * CDATA section _were they to exist_, it will indicate this as the type of comment. 327 * 328 * [2]: HTML recognizes processing instructions whose target starts with an ASCII letter 329 * or `_` and continues with ASCII alphanumerics, `-`, or `_`. The reserved `xml` 330 * and `xml-stylesheet` targets, as well as XML-valid targets with characters 331 * outside this set, transform into bogus comments in the DOM instead. Processing 332 * instructions exhibit the same constraint as CDATA sections, in that `>` cannot 333 * exist within the token since the processing instruction ends at the first `>`. 334 * 335 * ## Design and limitations 336 * 337 * The Tag Processor is designed to linearly scan HTML documents and tokenize 338 * HTML tags and their attributes. It's designed to do this as efficiently as 339 * possible without compromising parsing integrity. Therefore it will be 340 * slower than some methods of modifying HTML, such as those incorporating 341 * over-simplified PCRE patterns, but will not introduce the defects and 342 * failures that those methods bring in, which lead to broken page renders 343 * and often to security vulnerabilities. On the other hand, it will be faster 344 * than full-blown HTML parsers such as DOMDocument and use considerably 345 * less memory. It requires a negligible memory overhead, enough to consider 346 * it a zero-overhead system. 347 * 348 * The performance characteristics are maintained by avoiding tree construction 349 * and semantic cleanups which are specified in HTML5. Because of this, for 350 * example, it's not possible for the Tag Processor to associate any given 351 * opening tag with its corresponding closing tag, or to return the inner markup 352 * inside an element. Systems may be built on top of the Tag Processor to do 353 * this, but the Tag Processor is and should be constrained so it can remain an 354 * efficient, low-level, and reliable HTML scanner. 355 * 356 * The Tag Processor's design incorporates a "garbage-in-garbage-out" philosophy. 357 * HTML5 specifies that certain invalid content be transformed into different forms 358 * for display, such as removing null bytes from an input document and replacing 359 * invalid characters with the Unicode replacement character `U+FFFD` (visually "�"). 360 * Where errors or transformations exist within the HTML5 specification, the Tag Processor 361 * leaves those invalid inputs untouched, passing them through to the final browser 362 * to handle. While this implies that certain operations will be non-spec-compliant, 363 * such as reading the value of an attribute with invalid content, it also preserves a 364 * simplicity and efficiency for handling those error cases. 365 * 366 * Most operations within the Tag Processor are designed to minimize the difference 367 * between an input and output document for any given change. For example, the 368 * `add_class` and `remove_class` methods preserve whitespace and the class ordering 369 * within the `class` attribute; and when encountering tags with duplicated attributes, 370 * the Tag Processor will leave those invalid duplicate attributes where they are but 371 * update the proper attribute which the browser will read for parsing its value. An 372 * exception to this rule is that all attribute updates store their values as 373 * double-quoted strings, meaning that attributes on input with single-quoted or 374 * unquoted values will appear in the output with double-quotes. 375 * 376 * ### Scripting Flag 377 * 378 * The Tag Processor parses HTML with the "scripting flag" disabled. This means 379 * that it doesn't run any scripts while parsing the page. In a browser with 380 * JavaScript enabled, for example, the script can change the parse of the 381 * document as it loads. On the server, however, evaluating JavaScript is not 382 * only impractical, but also unwanted. 383 * 384 * Practically this means that the Tag Processor will descend into NOSCRIPT 385 * elements and process its child tags. Were the scripting flag enabled, such 386 * as in a typical browser, the contents of NOSCRIPT are skipped entirely. 387 * 388 * This allows the HTML API to process the content that will be presented in 389 * a browser when scripting is disabled, but it offers a different view of a 390 * page than most browser sessions will experience. E.g. the tags inside the 391 * NOSCRIPT disappear. 392 * 393 * ### Text Encoding 394 * 395 * The Tag Processor assumes that the input HTML document is encoded with a 396 * text encoding compatible with 7-bit ASCII's '<', '>', '&', ';', '/', '=', 397 * "'", '"', 'a' - 'z', 'A' - 'Z', and the whitespace characters ' ', tab, 398 * carriage-return, newline, and form-feed. 399 * 400 * In practice, this includes almost every single-byte encoding as well as 401 * UTF-8. Notably, however, it does not include UTF-16. If providing input 402 * that's incompatible, then convert the encoding beforehand. 403 * 404 * @since 6.2.0 405 * @since 6.2.1 Fix: Support for various invalid comments; attribute updates are case-insensitive. 406 * @since 6.3.2 Fix: Skip HTML-like content inside rawtext elements such as STYLE. 407 * @since 6.5.0 Pauses processor when input ends in an incomplete syntax token. 408 * Introduces "special" elements which act like void elements, e.g. TITLE, STYLE. 409 * Allows scanning through all tokens and processing modifiable text, where applicable. 410 */ 411 class WP_HTML_Tag_Processor { 412 /** 413 * The maximum number of bookmarks allowed to exist at 414 * any given time. 415 * 416 * @since 6.2.0 417 * @var int 418 * 419 * @see WP_HTML_Tag_Processor::set_bookmark() 420 */ 421 const MAX_BOOKMARKS = 10; 422 423 /** 424 * Maximum number of times seek() can be called. 425 * Prevents accidental infinite loops. 426 * 427 * @since 6.2.0 428 * @var int 429 * 430 * @see WP_HTML_Tag_Processor::seek() 431 */ 432 const MAX_SEEK_OPS = 1000; 433 434 /** 435 * The HTML document to parse. 436 * 437 * @since 6.2.0 438 * @var string 439 */ 440 protected $html; 441 442 /** 443 * The last query passed to next_tag(). 444 * 445 * @since 6.2.0 446 * @var array|null 447 */ 448 private $last_query; 449 450 /** 451 * The tag name this processor currently scans for. 452 * 453 * @since 6.2.0 454 * @var string|null 455 */ 456 private $sought_tag_name; 457 458 /** 459 * The CSS class name this processor currently scans for. 460 * 461 * @since 6.2.0 462 * @var string|null 463 */ 464 private $sought_class_name; 465 466 /** 467 * The match offset this processor currently scans for. 468 * 469 * @since 6.2.0 470 * @var int|null 471 */ 472 private $sought_match_offset; 473 474 /** 475 * Whether to visit tag closers, e.g. </div>, when walking an input document. 476 * 477 * @since 6.2.0 478 * @var bool 479 */ 480 private $stop_on_tag_closers; 481 482 /** 483 * Specifies mode of operation of the parser at any given time. 484 * 485 * | State | Meaning | 486 * |--------------------------|----------------------------------------------------------------------| 487 * | *Ready* | The parser is ready to run. | 488 * | *Complete* | There is nothing left to parse. | 489 * | *Incomplete* | The HTML ended in the middle of a token; nothing more can be parsed. | 490 * | *Matched tag* | Found an HTML tag; it's possible to modify its attributes. | 491 * | *Text node* | Found a #text node; this is plaintext and modifiable. | 492 * | *CDATA node* | Found a CDATA section; this is modifiable. | 493 * | *Comment* | Found a comment or bogus comment; this is modifiable. | 494 * | *Presumptuous* | Found an empty tag closer: `</>`. | 495 * | *Funky comment* | Found a tag closer with an invalid tag name; this is modifiable. | 496 * | *Processing instruction* | Found a processing instruction, e.g. `<?pi-target data>`. | 497 * 498 * @since 6.5.0 499 * 500 * @see WP_HTML_Tag_Processor::STATE_READY 501 * @see WP_HTML_Tag_Processor::STATE_COMPLETE 502 * @see WP_HTML_Tag_Processor::STATE_INCOMPLETE_INPUT 503 * @see WP_HTML_Tag_Processor::STATE_MATCHED_TAG 504 * @see WP_HTML_Tag_Processor::STATE_TEXT_NODE 505 * @see WP_HTML_Tag_Processor::STATE_CDATA_NODE 506 * @see WP_HTML_Tag_Processor::STATE_COMMENT 507 * @see WP_HTML_Tag_Processor::STATE_DOCTYPE 508 * @see WP_HTML_Tag_Processor::STATE_PRESUMPTUOUS_TAG 509 * @see WP_HTML_Tag_Processor::STATE_FUNKY_COMMENT 510 * @see WP_HTML_Tag_Processor::STATE_PROCESSING_INSTRUCTION 511 * 512 * @var string 513 */ 514 protected $parser_state = self::STATE_READY; 515 516 /** 517 * Indicates if the document is in quirks mode or no-quirks mode. 518 * 519 * Impact on HTML parsing: 520 * 521 * - In `NO_QUIRKS_MODE` (also known as "standard mode"): 522 * - CSS class and ID selectors match byte-for-byte (case-sensitively). 523 * - A TABLE start tag `<table>` implicitly closes any open `P` element. 524 * 525 * - In `QUIRKS_MODE`: 526 * - CSS class and ID selectors match in an ASCII case-insensitive manner. 527 * - A TABLE start tag `<table>` opens a `TABLE` element as a child of a `P` 528 * element if one is open. 529 * 530 * Quirks and no-quirks mode are thus mostly about styling, but have an impact when 531 * tables are found inside paragraph elements. 532 * 533 * @see self::QUIRKS_MODE 534 * @see self::NO_QUIRKS_MODE 535 * 536 * @since 6.7.0 537 * 538 * @var string 539 */ 540 protected $compat_mode = self::NO_QUIRKS_MODE; 541 542 /** 543 * Indicates whether the parser is inside foreign content, 544 * e.g. inside an SVG or MathML element. 545 * 546 * One of 'html', 'svg', or 'math'. 547 * 548 * Several parsing rules change based on whether the parser 549 * is inside foreign content, including whether CDATA sections 550 * are allowed and whether a self-closing flag indicates that 551 * an element has no content. 552 * 553 * @since 6.7.0 554 * 555 * @var string 556 */ 557 private $parsing_namespace = 'html'; 558 559 /** 560 * What kind of syntax token became an HTML comment. 561 * 562 * Since there are many ways in which HTML syntax can create an HTML comment, 563 * this indicates which of those caused it. This allows the Tag Processor to 564 * represent more from the original input document than would appear in the DOM. 565 * 566 * @since 6.5.0 567 * 568 * @var string|null 569 */ 570 protected $comment_type = null; 571 572 /** 573 * What kind of text the matched text node represents, if it was subdivided. 574 * 575 * @see self::TEXT_IS_NULL_SEQUENCE 576 * @see self::TEXT_IS_WHITESPACE 577 * @see self::TEXT_IS_GENERIC 578 * @see self::subdivide_text_appropriately 579 * 580 * @since 6.7.0 581 * 582 * @var string 583 */ 584 protected $text_node_classification = self::TEXT_IS_GENERIC; 585 586 /** 587 * How many bytes from the original HTML document have been read and parsed. 588 * 589 * This value points to the latest byte offset in the input document which 590 * has been already parsed. It is the internal cursor for the Tag Processor 591 * and updates while scanning through the HTML tokens. 592 * 593 * @since 6.2.0 594 * @var int 595 */ 596 private $bytes_already_parsed = 0; 597 598 /** 599 * Byte offset in input document where current token starts. 600 * 601 * Example: 602 * 603 * <div id="test">... 604 * 01234 605 * - token starts at 0 606 * 607 * @since 6.5.0 608 * 609 * @var int|null 610 */ 611 private $token_starts_at; 612 613 /** 614 * Byte length of current token. 615 * 616 * Example: 617 * 618 * <div id="test">... 619 * 0123456789012345 620 * - token length is 15 - 0 = 15 621 * 622 * a <!-- comment --> is a token. 623 * 0123456789 123456789 123456789 624 * - token length is 18 - 2 = 16 625 * 626 * @since 6.5.0 627 * 628 * @var int|null 629 */ 630 private $token_length; 631 632 /** 633 * Whether the current tag token has the self-closing flag. 634 * 635 * @since 7.1.0 636 * 637 * @var bool 638 */ 639 private $has_self_closing_flag = false; 640 641 /** 642 * Byte offset in input document where current tag name starts. 643 * 644 * Example: 645 * 646 * <div id="test">... 647 * 01234 648 * - tag name starts at 1 649 * 650 * @since 6.2.0 651 * 652 * @var int|null 653 */ 654 private $tag_name_starts_at; 655 656 /** 657 * Byte length of current tag name. 658 * 659 * Example: 660 * 661 * <div id="test">... 662 * 01234 663 * --- tag name length is 3 664 * 665 * @since 6.2.0 666 * 667 * @var int|null 668 */ 669 private $tag_name_length; 670 671 /** 672 * Byte offset into input document where current modifiable text starts. 673 * 674 * @since 6.5.0 675 * 676 * @var int 677 */ 678 private $text_starts_at; 679 680 /** 681 * Byte length of modifiable text. 682 * 683 * @since 6.5.0 684 * 685 * @var int 686 */ 687 private $text_length; 688 689 /** 690 * Whether the current tag is an opening tag, e.g. <div>, or a closing tag, e.g. </div>. 691 * 692 * @var bool 693 */ 694 private $is_closing_tag; 695 696 /** 697 * Lazily-built index of attributes found within an HTML tag, keyed by the attribute name. 698 * 699 * Example: 700 * 701 * // Supposing the parser is working through this content 702 * // and stops after recognizing the `id` attribute. 703 * // <div id="test-4" class=outline title="data:text/plain;base64=asdk3nk1j3fo8"> 704 * // ^ parsing will continue from this point. 705 * $this->attributes = array( 706 * 'id' => new WP_HTML_Attribute_Token( 'id', 9, 6, 5, 11, false ) 707 * ); 708 * 709 * // When picking up parsing again, or when asking to find the 710 * // `class` attribute we will continue and add to this array. 711 * $this->attributes = array( 712 * 'id' => new WP_HTML_Attribute_Token( 'id', 9, 6, 5, 11, false ), 713 * 'class' => new WP_HTML_Attribute_Token( 'class', 23, 7, 17, 13, false ) 714 * ); 715 * 716 * // Note that only the `class` attribute value is stored in the index. 717 * // That's because it is the only value used by this class at the moment. 718 * 719 * @since 6.2.0 720 * @var WP_HTML_Attribute_Token[] 721 * @phpstan-var array<non-empty-string, WP_HTML_Attribute_Token> 722 */ 723 private $attributes = array(); 724 725 /** 726 * Tracks spans of duplicate attributes on a given tag, used for removing 727 * all copies of an attribute when calling `remove_attribute()`. 728 * 729 * @since 6.3.2 730 * 731 * @var (WP_HTML_Span[])[]|null 732 */ 733 private $duplicate_attributes = null; 734 735 /** 736 * Which class names to add or remove from a tag. 737 * 738 * These are tracked separately from attribute updates because they are 739 * semantically distinct, whereas this interface exists for the common 740 * case of adding and removing class names while other attributes are 741 * generally modified as with DOM `setAttribute` calls. 742 * 743 * When modifying an HTML document these will eventually be collapsed 744 * into a single `set_attribute( 'class', $changes )` call. 745 * 746 * Example: 747 * 748 * // Add the `wp-block-group` class, remove the `wp-group` class. 749 * $classname_updates = array( 750 * // Indexed by a comparable class name. 751 * 'wp-block-group' => WP_HTML_Tag_Processor::ADD_CLASS, 752 * 'wp-group' => WP_HTML_Tag_Processor::REMOVE_CLASS 753 * ); 754 * 755 * @since 6.2.0 756 * @var array<non-empty-string, self::ADD_CLASS|self::REMOVE_CLASS> 757 */ 758 private $classname_updates = array(); 759 760 /** 761 * Tracks a semantic location in the original HTML which 762 * shifts with updates as they are applied to the document. 763 * 764 * @since 6.2.0 765 * @var WP_HTML_Span[] 766 */ 767 protected $bookmarks = array(); 768 769 const ADD_CLASS = true; 770 const REMOVE_CLASS = false; 771 const SKIP_CLASS = null; 772 773 /** 774 * Lexical replacements to apply to input HTML document. 775 * 776 * "Lexical" in this class refers to the part of this class which 777 * operates on pure text _as text_ and not as HTML. There's a line 778 * between the public interface, with HTML-semantic methods like 779 * `set_attribute` and `add_class`, and an internal state that tracks 780 * text offsets in the input document. 781 * 782 * When higher-level HTML methods are called, those have to transform their 783 * operations (such as setting an attribute's value) into text diffing 784 * operations (such as replacing the sub-string from indices A to B with 785 * some given new string). These text-diffing operations are the lexical 786 * updates. 787 * 788 * As new higher-level methods are added they need to collapse their 789 * operations into these lower-level lexical updates since that's the 790 * Tag Processor's internal language of change. Any code which creates 791 * these lexical updates must ensure that they do not cross HTML syntax 792 * boundaries, however, so these should never be exposed outside of this 793 * class or any classes which intentionally expand its functionality. 794 * 795 * These are enqueued while editing the document instead of being immediately 796 * applied to avoid processing overhead, string allocations, and string 797 * copies when applying many updates to a single document. 798 * 799 * Example: 800 * 801 * // Replace an attribute stored with a new value, indices 802 * // sourced from the lazily-parsed HTML recognizer. 803 * $start = $attributes['src']->start; 804 * $length = $attributes['src']->length; 805 * $modifications[] = new WP_HTML_Text_Replacement( $start, $length, $new_value ); 806 * 807 * // Correspondingly, something like this will appear in this array. 808 * $lexical_updates = array( 809 * WP_HTML_Text_Replacement( 14, 28, 'https://my-site.my-domain/wp-content/uploads/2014/08/kittens.jpg' ) 810 * ); 811 * 812 * @since 6.2.0 813 * @var array<int|string, WP_HTML_Text_Replacement> 814 */ 815 protected $lexical_updates = array(); 816 817 /** 818 * Tracks and limits `seek()` calls to prevent accidental infinite loops. 819 * 820 * @since 6.2.0 821 * @var int 822 * 823 * @see WP_HTML_Tag_Processor::seek() 824 */ 825 protected $seek_count = 0; 826 827 /** 828 * Whether the parser should skip over an immediately-following linefeed 829 * character, as is the case with LISTING, PRE, and TEXTAREA. 830 * 831 * > If the next token is a U+000A LINE FEED (LF) character token, then 832 * > ignore that token and move on to the next one. (Newlines at the start 833 * > of [these] elements are ignored as an authoring convenience.) 834 * 835 * @since 6.7.0 836 * 837 * @var int|null 838 */ 839 private $skip_newline_at = null; 840 841 /** 842 * Constructor. 843 * 844 * @since 6.2.0 845 * 846 * @param string $html HTML to process. 847 */ 848 public function __construct( $html ) { 849 if ( ! is_string( $html ) ) { 850 _doing_it_wrong( 851 __METHOD__, 852 __( 'The HTML parameter must be a string.' ), 853 '6.9.0' 854 ); 855 $html = ''; 856 } 857 $this->html = $html; 858 } 859 860 /** 861 * Switches parsing mode into a new namespace, such as when 862 * encountering an SVG tag and entering foreign content. 863 * 864 * @since 6.7.0 865 * 866 * @param string $new_namespace One of 'html', 'svg', or 'math' indicating into what 867 * namespace the next tokens will be processed. 868 * @return bool Whether the namespace was valid and changed. 869 */ 870 public function change_parsing_namespace( string $new_namespace ): bool { 871 if ( ! in_array( $new_namespace, array( 'html', 'math', 'svg' ), true ) ) { 872 return false; 873 } 874 875 $this->parsing_namespace = $new_namespace; 876 return true; 877 } 878 879 /** 880 * Finds the next tag matching the $query. 881 * 882 * @since 6.2.0 883 * @since 6.5.0 No longer processes incomplete tokens at end of document; pauses the processor at start of token. 884 * 885 * @param array|string|null $query { 886 * Optional. Which tag name to find, having which class, etc. Default is to find any tag. 887 * 888 * @type string|null $tag_name Which tag to find, or `null` for "any tag." 889 * @type int|null $match_offset Find the Nth tag matching all search criteria. 890 * 1 for "first" tag, 3 for "third," etc. 891 * Defaults to first tag. 892 * @type string|null $class_name Tag must contain this whole class name to match. 893 * @type string|null $tag_closers "visit" or "skip": whether to stop on tag closers, e.g. </div>. 894 * } 895 * @return bool Whether a tag was matched. 896 * 897 * @phpstan-impure 898 */ 899 public function next_tag( $query = null ): bool { 900 $this->parse_query( $query ); 901 $already_found = 0; 902 903 do { 904 if ( false === $this->next_token() ) { 905 return false; 906 } 907 908 if ( self::STATE_MATCHED_TAG !== $this->parser_state ) { 909 continue; 910 } 911 912 if ( $this->matches() ) { 913 ++$already_found; 914 } 915 } while ( $already_found < $this->sought_match_offset ); 916 917 return true; 918 } 919 920 /** 921 * Finds the next token in the HTML document. 922 * 923 * An HTML document can be viewed as a stream of tokens, 924 * where tokens are things like HTML tags, HTML comments, 925 * text nodes, etc. This method finds the next token in 926 * the HTML document and returns whether it found one. 927 * 928 * If it starts parsing a token and reaches the end of the 929 * document then it will seek to the start of the last 930 * token and pause, returning `false` to indicate that it 931 * failed to find a complete token. 932 * 933 * Possible token types, based on the HTML specification: 934 * 935 * - an HTML tag, whether opening, closing, or void. 936 * - a text node - the plaintext inside tags. 937 * - an HTML comment. 938 * - a DOCTYPE declaration. 939 * - an HTML processing instruction, e.g. `<?pi …data?>`. 940 * 941 * @since 6.5.0 942 * @since 6.7.0 Recognizes CDATA sections within foreign content. 943 * @since 7.1.0 Recognizes processing instructions. 944 * 945 * @return bool Whether a token was parsed. 946 */ 947 public function next_token(): bool { 948 return $this->base_class_next_token(); 949 } 950 951 /** 952 * Internal method which finds the next token in the HTML document. 953 * 954 * This method is a protected internal function which implements the logic for 955 * finding the next token in a document. It exists so that the parser can update 956 * its state without affecting the location of the cursor in the document and 957 * without triggering subclass methods for things like `next_token()`, e.g. when 958 * applying patches before searching for the next token. 959 * 960 * @since 6.5.0 961 * @ignore 962 * 963 * @return bool Whether a token was parsed. 964 */ 965 private function base_class_next_token(): bool { 966 $was_at = $this->bytes_already_parsed; 967 $this->after_tag(); 968 969 // Don't proceed if there's nothing more to scan. 970 if ( 971 self::STATE_COMPLETE === $this->parser_state || 972 self::STATE_INCOMPLETE_INPUT === $this->parser_state 973 ) { 974 return false; 975 } 976 977 /* 978 * The next step in the parsing loop determines the parsing state; 979 * clear it so that state doesn't linger from the previous step. 980 */ 981 $this->parser_state = self::STATE_READY; 982 983 if ( $this->bytes_already_parsed >= strlen( $this->html ) ) { 984 $this->parser_state = self::STATE_COMPLETE; 985 return false; 986 } 987 988 // Find the next tag if it exists. 989 if ( false === $this->parse_next_tag() ) { 990 if ( self::STATE_INCOMPLETE_INPUT === $this->parser_state ) { 991 $this->bytes_already_parsed = $was_at; 992 } 993 994 return false; 995 } 996 997 /* 998 * For legacy reasons the rest of this function handles tags and their 999 * attributes. If the processor has reached the end of the document 1000 * or if it matched any other token then it should return here to avoid 1001 * attempting to process tag-specific syntax. 1002 */ 1003 if ( 1004 self::STATE_INCOMPLETE_INPUT !== $this->parser_state && 1005 self::STATE_COMPLETE !== $this->parser_state && 1006 self::STATE_MATCHED_TAG !== $this->parser_state 1007 ) { 1008 return true; 1009 } 1010 1011 // Parse all of its attributes. 1012 while ( $this->parse_next_attribute() ) { 1013 continue; 1014 } 1015 1016 // Ensure that the tag closes before the end of the document. 1017 if ( 1018 self::STATE_INCOMPLETE_INPUT === $this->parser_state || 1019 $this->bytes_already_parsed >= strlen( $this->html ) 1020 ) { 1021 // Does this appropriately clear state (parsed attributes)? 1022 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 1023 $this->bytes_already_parsed = $was_at; 1024 1025 return false; 1026 } 1027 1028 $tag_ends_at = strpos( $this->html, '>', $this->bytes_already_parsed ); 1029 if ( false === $tag_ends_at ) { 1030 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 1031 $this->bytes_already_parsed = $was_at; 1032 1033 return false; 1034 } 1035 $this->parser_state = self::STATE_MATCHED_TAG; 1036 $this->bytes_already_parsed = $tag_ends_at + 1; 1037 $this->token_length = $this->bytes_already_parsed - $this->token_starts_at; 1038 1039 /* 1040 * Certain tags require additional processing. The first-letter pre-check 1041 * avoids unnecessary string allocation when comparing the tag names. 1042 * 1043 * - IFRAME 1044 * - LISTING (deprecated) 1045 * - NOEMBED (deprecated) 1046 * - NOFRAMES (deprecated) 1047 * - PRE 1048 * - SCRIPT 1049 * - STYLE 1050 * - TEXTAREA 1051 * - TITLE 1052 * - XMP (deprecated) 1053 */ 1054 if ( 1055 $this->is_closing_tag || 1056 'html' !== $this->parsing_namespace || 1057 1 !== strspn( $this->html, 'iIlLnNpPsStTxX', $this->tag_name_starts_at, 1 ) 1058 ) { 1059 return true; 1060 } 1061 1062 $tag_name = $this->get_tag(); 1063 1064 /* 1065 * For LISTING, PRE, and TEXTAREA, the first linefeed of an immediately-following 1066 * text node is ignored as an authoring convenience. 1067 * 1068 * @see static::skip_newline_at 1069 */ 1070 if ( 'LISTING' === $tag_name || 'PRE' === $tag_name ) { 1071 $this->skip_newline_at = $this->bytes_already_parsed; 1072 return true; 1073 } 1074 1075 /* 1076 * There are certain elements whose children are not DATA but are instead 1077 * RCDATA or RAWTEXT. These cannot contain other elements, and the contents 1078 * are parsed as plaintext, with character references decoded in RCDATA but 1079 * not in RAWTEXT. 1080 * 1081 * These elements are described here as "self-contained" or special atomic 1082 * elements whose end tag is consumed with the opening tag, and they will 1083 * contain modifiable text inside of them. 1084 * 1085 * Preserve the opening tag pointers, as these will be overwritten 1086 * when finding the closing tag. They will be reset after finding 1087 * the closing tag to point to the opening of the special atomic 1088 * tag sequence. 1089 */ 1090 $tag_name_starts_at = $this->tag_name_starts_at; 1091 $tag_name_length = $this->tag_name_length; 1092 $tag_ends_at = $this->token_starts_at + $this->token_length; 1093 $has_self_closing_flag = $this->has_self_closing_flag; 1094 $attributes = $this->attributes; 1095 $duplicate_attributes = $this->duplicate_attributes; 1096 1097 // Find the closing tag if necessary. 1098 switch ( $tag_name ) { 1099 case 'SCRIPT': 1100 $found_closer = $this->skip_script_data(); 1101 break; 1102 1103 case 'TEXTAREA': 1104 case 'TITLE': 1105 $found_closer = $this->skip_rcdata( $tag_name ); 1106 break; 1107 1108 /* 1109 * In the browser this list would include the NOSCRIPT element, 1110 * but the Tag Processor is an environment with the scripting 1111 * flag disabled, meaning that it needs to descend into the 1112 * NOSCRIPT element to be able to properly process what will be 1113 * sent to a browser. 1114 * 1115 * Note that this rule makes HTML5 syntax incompatible with XML, 1116 * because the parsing of this token depends on client application. 1117 * The NOSCRIPT element cannot be represented in the XHTML syntax. 1118 */ 1119 case 'IFRAME': 1120 case 'NOEMBED': 1121 case 'NOFRAMES': 1122 case 'STYLE': 1123 case 'XMP': 1124 $found_closer = $this->skip_rawtext( $tag_name ); 1125 break; 1126 1127 // No other tags should be treated in their entirety here. 1128 default: 1129 return true; 1130 } 1131 1132 if ( ! $found_closer ) { 1133 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 1134 $this->bytes_already_parsed = $was_at; 1135 return false; 1136 } 1137 1138 /* 1139 * The values here look like they reference the opening tag but they reference 1140 * the closing tag instead. This is why the opening tag values were stored 1141 * above in a variable. It reads confusingly here, but that's because the 1142 * functions that skip the contents have moved all the internal cursors past 1143 * the inner content of the tag. 1144 */ 1145 $this->token_starts_at = $was_at; 1146 $this->token_length = $this->bytes_already_parsed - $this->token_starts_at; 1147 $this->text_starts_at = $tag_ends_at; 1148 $this->text_length = $this->tag_name_starts_at - $this->text_starts_at; 1149 $this->tag_name_starts_at = $tag_name_starts_at; 1150 $this->tag_name_length = $tag_name_length; 1151 $this->has_self_closing_flag = $has_self_closing_flag; 1152 $this->attributes = $attributes; 1153 $this->duplicate_attributes = $duplicate_attributes; 1154 1155 return true; 1156 } 1157 1158 /** 1159 * Whether the processor paused because the input HTML document ended 1160 * in the middle of a syntax element, such as in the middle of a tag. 1161 * 1162 * Example: 1163 * 1164 * $processor = new WP_HTML_Tag_Processor( '<input type="text" value="Th' ); 1165 * false === $processor->next_tag(); 1166 * true === $processor->paused_at_incomplete_token(); 1167 * 1168 * @since 6.5.0 1169 * 1170 * @return bool Whether the parse paused at the start of an incomplete token. 1171 */ 1172 public function paused_at_incomplete_token(): bool { 1173 return self::STATE_INCOMPLETE_INPUT === $this->parser_state; 1174 } 1175 1176 /** 1177 * Generator for a foreach loop to step through each class name for the matched tag. 1178 * 1179 * This generator function is designed to be used inside a "foreach" loop. 1180 * 1181 * ```php interactive 1182 * <?php 1183 * require '/wordpress/wp-load.php'; 1184 * $p = new WP_HTML_Tag_Processor( "<div class='free <egg>\tlang-en'>" ); 1185 * $p->next_tag(); 1186 * foreach ( $p->class_list() as $class_name ) { 1187 * var_dump( $class_name ); 1188 * } 1189 * ``` 1190 * ```expected-output 1191 * string(4) "free" 1192 * string(5) "<egg>" 1193 * string(7) "lang-en" 1194 * ``` 1195 * 1196 * @since 6.4.0 1197 * 1198 * @return Generator<int, non-empty-string> 1199 */ 1200 public function class_list() { 1201 if ( self::STATE_MATCHED_TAG !== $this->parser_state ) { 1202 return; 1203 } 1204 1205 /** @var string $class contains the string value of the class attribute, with character references decoded. */ 1206 $class = $this->get_attribute( 'class' ); 1207 1208 if ( ! is_string( $class ) ) { 1209 return; 1210 } 1211 1212 $seen = array(); 1213 1214 $is_quirks = self::QUIRKS_MODE === $this->compat_mode; 1215 1216 $at = 0; 1217 while ( $at < strlen( $class ) ) { 1218 // Skip past any initial boundary characters. 1219 $at += strspn( $class, " \t\f\r\n", $at ); 1220 if ( $at >= strlen( $class ) ) { 1221 return; 1222 } 1223 1224 // Find the byte length until the next boundary. 1225 $length = strcspn( $class, " \t\f\r\n", $at ); 1226 if ( 0 === $length ) { 1227 return; 1228 } 1229 1230 $name = substr( $class, $at, $length ); 1231 if ( $is_quirks ) { 1232 $name = strtolower( $name ); 1233 } 1234 $at += $length; 1235 1236 /* 1237 * It's expected that the number of class names for a given tag is relatively small. 1238 * Given this, it is probably faster overall to scan an array for a value rather 1239 * than to use the class name as a key and check if it's a key of $seen. 1240 */ 1241 if ( in_array( $name, $seen, true ) ) { 1242 continue; 1243 } 1244 1245 $seen[] = $name; 1246 yield $name; 1247 } 1248 } 1249 1250 1251 /** 1252 * Returns if a matched tag contains the given ASCII case-insensitive class name. 1253 * 1254 * @since 6.4.0 1255 * 1256 * @param string $wanted_class Look for this CSS class name, ASCII case-insensitive. 1257 * @return bool|null Whether the matched tag contains the given class name, or null if not matched. 1258 */ 1259 public function has_class( $wanted_class ): ?bool { 1260 if ( self::STATE_MATCHED_TAG !== $this->parser_state ) { 1261 return null; 1262 } 1263 1264 $case_insensitive = self::QUIRKS_MODE === $this->compat_mode; 1265 1266 $wanted_length = strlen( $wanted_class ); 1267 foreach ( $this->class_list() as $class_name ) { 1268 if ( 1269 strlen( $class_name ) === $wanted_length && 1270 0 === substr_compare( $class_name, $wanted_class, 0, strlen( $wanted_class ), $case_insensitive ) 1271 ) { 1272 return true; 1273 } 1274 } 1275 1276 return false; 1277 } 1278 1279 1280 /** 1281 * Sets a bookmark in the HTML document. 1282 * 1283 * Bookmarks represent specific places or tokens in the HTML 1284 * document, such as a tag opener or closer. When applying 1285 * edits to a document, such as setting an attribute, the 1286 * text offsets of that token may shift; the bookmark is 1287 * kept updated with those shifts and remains stable unless 1288 * the entire span of text in which the token sits is removed. 1289 * 1290 * Release bookmarks when they are no longer needed. 1291 * 1292 * Example: 1293 * 1294 * <main><h2>Surprising fact you may not know!</h2></main> 1295 * ^ ^ 1296 * \-|-- this `H2` opener bookmark tracks the token 1297 * 1298 * <main class="clickbait"><h2>Surprising fact you may no… 1299 * ^ ^ 1300 * \-|-- it shifts with edits 1301 * 1302 * Bookmarks provide the ability to seek to a previously-scanned 1303 * place in the HTML document. This avoids the need to re-scan 1304 * the entire document. 1305 * 1306 * Example: 1307 * 1308 * <ul><li>One</li><li>Two</li><li>Three</li></ul> 1309 * ^^^^ 1310 * want to note this last item 1311 * 1312 * $p = new WP_HTML_Tag_Processor( $html ); 1313 * $in_list = false; 1314 * while ( $p->next_tag( array( 'tag_closers' => $in_list ? 'visit' : 'skip' ) ) ) { 1315 * if ( 'UL' === $p->get_tag() ) { 1316 * if ( $p->is_tag_closer() ) { 1317 * $in_list = false; 1318 * $p->set_bookmark( 'resume' ); 1319 * if ( $p->seek( 'last-li' ) ) { 1320 * $p->add_class( 'last-li' ); 1321 * } 1322 * $p->seek( 'resume' ); 1323 * $p->release_bookmark( 'last-li' ); 1324 * $p->release_bookmark( 'resume' ); 1325 * } else { 1326 * $in_list = true; 1327 * } 1328 * } 1329 * 1330 * if ( 'LI' === $p->get_tag() ) { 1331 * $p->set_bookmark( 'last-li' ); 1332 * } 1333 * } 1334 * 1335 * Bookmarks intentionally hide the internal string offsets 1336 * to which they refer. They are maintained internally as 1337 * updates are applied to the HTML document and therefore 1338 * retain their "position" - the location to which they 1339 * originally pointed. The inability to use bookmarks with 1340 * functions like `substr` is therefore intentional to guard 1341 * against accidentally breaking the HTML. 1342 * 1343 * Because bookmarks allocate memory and require processing 1344 * for every applied update, they are limited and require 1345 * a name. They should not be created with programmatically-made 1346 * names, such as "li_{$index}" with some loop. As a general 1347 * rule they should only be created with string-literal names 1348 * like "start-of-section" or "last-paragraph". 1349 * 1350 * Bookmarks are a powerful tool to enable complicated behavior. 1351 * Consider double-checking that you need this tool if you are 1352 * reaching for it, as inappropriate use could lead to broken 1353 * HTML structure or unwanted processing overhead. 1354 * 1355 * @since 6.2.0 1356 * 1357 * @param string $name Identifies this particular bookmark. 1358 * @return bool Whether the bookmark was successfully created. 1359 */ 1360 public function set_bookmark( $name ): bool { 1361 // It only makes sense to set a bookmark if the parser has paused on a concrete token. 1362 if ( 1363 self::STATE_COMPLETE === $this->parser_state || 1364 self::STATE_INCOMPLETE_INPUT === $this->parser_state 1365 ) { 1366 return false; 1367 } 1368 1369 if ( ! array_key_exists( $name, $this->bookmarks ) && count( $this->bookmarks ) >= static::MAX_BOOKMARKS ) { 1370 _doing_it_wrong( 1371 __METHOD__, 1372 __( 'Too many bookmarks: cannot create any more.' ), 1373 '6.2.0' 1374 ); 1375 return false; 1376 } 1377 1378 $this->bookmarks[ $name ] = new WP_HTML_Span( $this->token_starts_at, $this->token_length ); 1379 1380 return true; 1381 } 1382 1383 1384 /** 1385 * Removes a bookmark that is no longer needed. 1386 * 1387 * Releasing a bookmark frees up the small 1388 * performance overhead it requires. 1389 * 1390 * @param string $name Name of the bookmark to remove. 1391 * @return bool Whether the bookmark already existed before removal. 1392 */ 1393 public function release_bookmark( $name ): bool { 1394 if ( ! array_key_exists( $name, $this->bookmarks ) ) { 1395 return false; 1396 } 1397 1398 unset( $this->bookmarks[ $name ] ); 1399 1400 return true; 1401 } 1402 1403 /** 1404 * Skips contents of generic rawtext elements. 1405 * 1406 * @since 6.3.2 1407 * @ignore 1408 * 1409 * @see https://html.spec.whatwg.org/#generic-raw-text-element-parsing-algorithm 1410 * 1411 * @param string $tag_name The uppercase tag name which will close the RAWTEXT region. 1412 * @return bool Whether an end to the RAWTEXT region was found before the end of the document. 1413 */ 1414 private function skip_rawtext( string $tag_name ): bool { 1415 /* 1416 * These two functions distinguish themselves on whether character references are 1417 * decoded, and since functionality to read the inner markup isn't supported, it's 1418 * not necessary to implement these two functions separately. 1419 */ 1420 return $this->skip_rcdata( $tag_name ); 1421 } 1422 1423 /** 1424 * Skips contents of RCDATA elements, namely title and textarea tags. 1425 * 1426 * @since 6.2.0 1427 * @ignore 1428 * 1429 * @see https://html.spec.whatwg.org/multipage/parsing.html#rcdata-state 1430 * 1431 * @param string $tag_name The uppercase tag name which will close the RCDATA region. 1432 * @return bool Whether an end to the RCDATA region was found before the end of the document. 1433 */ 1434 private function skip_rcdata( string $tag_name ): bool { 1435 $html = $this->html; 1436 $doc_length = strlen( $html ); 1437 $tag_length = strlen( $tag_name ); 1438 1439 $at = $this->bytes_already_parsed; 1440 1441 while ( false !== $at && $at < $doc_length ) { 1442 $at = strpos( $this->html, '</', $at ); 1443 $this->tag_name_starts_at = $at; 1444 1445 // Fail if there is no possible tag closer. 1446 if ( false === $at || ( $at + 2 + $tag_length ) >= $doc_length ) { 1447 return false; 1448 } 1449 1450 $at += 2; 1451 1452 /* 1453 * Find a case-insensitive match to the tag name. 1454 * 1455 * Because tag names are limited to US-ASCII there is no 1456 * need to perform any kind of Unicode normalization when 1457 * comparing; any character which could be impacted by such 1458 * normalization could not be part of a tag name. 1459 */ 1460 for ( $i = 0; $i < $tag_length; $i++ ) { 1461 $tag_char = $tag_name[ $i ]; 1462 $html_char = $html[ $at + $i ]; 1463 1464 if ( $html_char !== $tag_char && strtoupper( $html_char ) !== $tag_char ) { 1465 $at += $i; 1466 continue 2; 1467 } 1468 } 1469 1470 $at += $tag_length; 1471 $this->bytes_already_parsed = $at; 1472 1473 if ( $at >= strlen( $html ) ) { 1474 return false; 1475 } 1476 1477 /* 1478 * Ensure that the tag name terminates to avoid matching on 1479 * substrings of a longer tag name. For example, the sequence 1480 * "</textarearug" should not match for "</textarea" even 1481 * though "textarea" is found within the text. 1482 */ 1483 $c = $html[ $at ]; 1484 if ( ' ' !== $c && "\t" !== $c && "\f" !== $c && "\r" !== $c && "\n" !== $c && '/' !== $c && '>' !== $c ) { 1485 continue; 1486 } 1487 1488 while ( $this->parse_next_attribute() ) { 1489 continue; 1490 } 1491 1492 $at = $this->bytes_already_parsed; 1493 if ( $at >= strlen( $this->html ) ) { 1494 return false; 1495 } 1496 1497 if ( '>' === $html[ $at ] ) { 1498 $this->bytes_already_parsed = $at + 1; 1499 return true; 1500 } 1501 1502 if ( $at + 1 >= strlen( $this->html ) ) { 1503 return false; 1504 } 1505 1506 if ( '/' === $html[ $at ] && '>' === $html[ $at + 1 ] ) { 1507 $this->bytes_already_parsed = $at + 2; 1508 return true; 1509 } 1510 } 1511 1512 return false; 1513 } 1514 1515 /** 1516 * Skips contents of script tags. 1517 * 1518 * @since 6.2.0 1519 * @ignore 1520 * 1521 * @return bool Whether the script tag was closed before the end of the document. 1522 */ 1523 private function skip_script_data(): bool { 1524 $state = 'unescaped'; 1525 $html = $this->html; 1526 $doc_length = strlen( $html ); 1527 $at = $this->bytes_already_parsed; 1528 1529 while ( false !== $at && $at < $doc_length ) { 1530 $at += strcspn( $html, '-<', $at ); 1531 1532 /* 1533 * Optimization: Terminating a complete script element requires at least eight 1534 * additional bytes in the document. Some checks below may cause local escaped 1535 * state transitions when processing shorter strings, but those transitions are 1536 * irrelevant if the script tag is incomplete and the function must return false. 1537 * 1538 * This may need updating if those transitions become significant or exported from 1539 * this function in some way, such as when building safe methods to embed JavaScript 1540 * or data inside a SCRIPT element. 1541 * 1542 * $at may be here. 1543 * ↓ 1544 * ...</script> 1545 * ╰──┬───╯ 1546 * $at + 8 additional bytes are required for a non-false return value. 1547 * 1548 * This single check eliminates the need to check lengths for the shorter spans: 1549 * 1550 * $at may be here. 1551 * ↓ 1552 * <script><!-- --></script> 1553 * ├╯ 1554 * $at + 2 additional characters does not require a length check. 1555 * 1556 * The transition from "escaped" to "unescaped" is not relevant if the document ends: 1557 * 1558 * $at may be here. 1559 * ↓ 1560 * <script><!-- -->[[END-OF-DOCUMENT]] 1561 * ╰──┬───╯ 1562 * $at + 8 additional bytes is not satisfied, return false. 1563 */ 1564 if ( $at + 8 >= $doc_length ) { 1565 return false; 1566 } 1567 1568 /* 1569 * For all script states a "-->" transitions 1570 * back into the normal unescaped script mode, 1571 * even if that's the current state. 1572 */ 1573 if ( 1574 '-' === $html[ $at ] && 1575 '-' === $html[ $at + 1 ] && 1576 '>' === $html[ $at + 2 ] 1577 ) { 1578 $at += 3; 1579 $state = 'unescaped'; 1580 continue; 1581 } 1582 1583 /* 1584 * Everything of interest past here starts with "<". 1585 * Check this character and advance position regardless. 1586 */ 1587 if ( '<' !== $html[ $at++ ] ) { 1588 continue; 1589 } 1590 1591 /* 1592 * "<!--" only transitions from _unescaped_ to _escaped_. This byte sequence is only 1593 * significant in the _unescaped_ state and is ignored in any other state. 1594 */ 1595 if ( 1596 'unescaped' === $state && 1597 '!' === $html[ $at ] && 1598 '-' === $html[ $at + 1 ] && 1599 '-' === $html[ $at + 2 ] 1600 ) { 1601 $at += 3; 1602 1603 /* 1604 * The parser is ready to enter the _escaped_ state, but may remain in the 1605 * _unescaped_ state. This occurs when "<!--" is immediately followed by a 1606 * sequence of 0 or more "-" followed by ">". This is similar to abruptly closed 1607 * HTML comments like "<!-->" or "<!--->". 1608 * 1609 * Note that this check may advance the position significantly and requires a 1610 * length check to prevent bad offsets on inputs like `<script><!---------`. 1611 */ 1612 $at += strspn( $html, '-', $at ); 1613 if ( $at < $doc_length && '>' === $html[ $at ] ) { 1614 ++$at; 1615 continue; 1616 } 1617 1618 $state = 'escaped'; 1619 continue; 1620 } 1621 1622 if ( '/' === $html[ $at ] ) { 1623 $closer_potentially_starts_at = $at - 1; 1624 $is_closing = true; 1625 ++$at; 1626 } else { 1627 $is_closing = false; 1628 } 1629 1630 /* 1631 * At this point the only remaining state-changes occur with the 1632 * <script> and </script> tags; unless one of these appears next, 1633 * proceed scanning to the next potential token in the text. 1634 */ 1635 if ( ! ( 1636 ( 's' === $html[ $at ] || 'S' === $html[ $at ] ) && 1637 ( 'c' === $html[ $at + 1 ] || 'C' === $html[ $at + 1 ] ) && 1638 ( 'r' === $html[ $at + 2 ] || 'R' === $html[ $at + 2 ] ) && 1639 ( 'i' === $html[ $at + 3 ] || 'I' === $html[ $at + 3 ] ) && 1640 ( 'p' === $html[ $at + 4 ] || 'P' === $html[ $at + 4 ] ) && 1641 ( 't' === $html[ $at + 5 ] || 'T' === $html[ $at + 5 ] ) 1642 ) ) { 1643 continue; 1644 } 1645 1646 /* 1647 * Ensure that the script tag terminates to avoid matching on 1648 * substrings of a non-match. For example, the sequence 1649 * "<script123" should not end a script region even though 1650 * "<script" is found within the text. 1651 */ 1652 $at += 6; 1653 $c = $html[ $at ]; 1654 if ( 1655 /** 1656 * These characters trigger state transitions of interest: 1657 * 1658 * - @see {https://html.spec.whatwg.org/multipage/parsing.html#script-data-end-tag-name-state} 1659 * - @see {https://html.spec.whatwg.org/multipage/parsing.html#script-data-escaped-end-tag-name-state} 1660 * - @see {https://html.spec.whatwg.org/multipage/parsing.html#script-data-double-escape-start-state} 1661 * - @see {https://html.spec.whatwg.org/multipage/parsing.html#script-data-double-escape-end-state} 1662 * 1663 * The "\r" character is not present in the above references. However, "\r" must be 1664 * treated the same as "\n". This is because the HTML Standard requires newline 1665 * normalization during preprocessing which applies this replacement. 1666 * 1667 * - @see https://html.spec.whatwg.org/multipage/parsing.html#preprocessing-the-input-stream 1668 * - @see https://infra.spec.whatwg.org/#normalize-newlines 1669 */ 1670 '>' !== $c && 1671 ' ' !== $c && 1672 "\n" !== $c && 1673 '/' !== $c && 1674 "\t" !== $c && 1675 "\f" !== $c && 1676 "\r" !== $c 1677 ) { 1678 continue; 1679 } 1680 1681 if ( 'escaped' === $state && ! $is_closing ) { 1682 $state = 'double-escaped'; 1683 continue; 1684 } 1685 1686 if ( 'double-escaped' === $state && $is_closing ) { 1687 $state = 'escaped'; 1688 continue; 1689 } 1690 1691 if ( $is_closing ) { 1692 $this->bytes_already_parsed = $closer_potentially_starts_at; 1693 $this->tag_name_starts_at = $closer_potentially_starts_at; 1694 if ( $this->bytes_already_parsed >= $doc_length ) { 1695 return false; 1696 } 1697 1698 while ( $this->parse_next_attribute() ) { 1699 continue; 1700 } 1701 1702 if ( $this->bytes_already_parsed >= $doc_length ) { 1703 return false; 1704 } 1705 1706 if ( '>' === $html[ $this->bytes_already_parsed ] ) { 1707 ++$this->bytes_already_parsed; 1708 return true; 1709 } 1710 } 1711 1712 ++$at; 1713 } 1714 1715 return false; 1716 } 1717 1718 /** 1719 * Parses the next tag. 1720 * 1721 * This will find and start parsing the next tag, including 1722 * the opening `<`, the potential closer `/`, and the tag 1723 * name. It does not parse the attributes or scan to the 1724 * closing `>`; these are left for other methods. 1725 * 1726 * @since 6.2.0 1727 * @since 6.2.1 Support abruptly-closed comments, invalid-tag-closer-comments, and empty elements. 1728 * @ignore 1729 * 1730 * @return bool Whether a tag was found before the end of the document. 1731 * 1732 * @phpstan-impure 1733 */ 1734 private function parse_next_tag(): bool { 1735 $this->after_tag(); 1736 1737 $html = $this->html; 1738 $doc_length = strlen( $html ); 1739 $was_at = $this->bytes_already_parsed; 1740 $at = $was_at; 1741 1742 while ( $at < $doc_length ) { 1743 $at = strpos( $html, '<', $at ); 1744 if ( false === $at ) { 1745 break; 1746 } 1747 1748 if ( $at > $was_at ) { 1749 /* 1750 * A "<" normally starts a new HTML tag or syntax token, but in cases where the 1751 * following character can't produce a valid token, the "<" is instead treated 1752 * as plaintext and the parser should skip over it. This avoids a problem when 1753 * following earlier practices of typing emoji with text, e.g. "<3". This 1754 * should be a heart, not a tag. It's supposed to be rendered, not hidden. 1755 * 1756 * At this point the parser checks if this is one of those cases and if it is 1757 * will continue searching for the next "<" in search of a token boundary. 1758 * 1759 * @see https://html.spec.whatwg.org/#tag-open-state 1760 */ 1761 if ( 1 !== strspn( $html, '!/?abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ', $at + 1, 1 ) ) { 1762 ++$at; 1763 continue; 1764 } 1765 1766 $this->parser_state = self::STATE_TEXT_NODE; 1767 $this->token_starts_at = $was_at; 1768 $this->token_length = $at - $was_at; 1769 $this->text_starts_at = $was_at; 1770 $this->text_length = $this->token_length; 1771 $this->bytes_already_parsed = $at; 1772 return true; 1773 } 1774 1775 $this->token_starts_at = $at; 1776 1777 if ( $at + 1 < $doc_length && '/' === $this->html[ $at + 1 ] ) { 1778 $this->is_closing_tag = true; 1779 ++$at; 1780 } else { 1781 $this->is_closing_tag = false; 1782 } 1783 1784 /* 1785 * HTML tag names must start with [a-zA-Z] otherwise they are not tags. 1786 * For example, "<3" is rendered as text, not a tag opener. If at least 1787 * one letter follows the "<" then _it is_ a tag, but if the following 1788 * character is anything else it _is not a tag_. 1789 * 1790 * It's not uncommon to find non-tags starting with `<` in an HTML 1791 * document, so it's good for performance to make this pre-check before 1792 * continuing to attempt to parse a tag name. 1793 * 1794 * Reference: 1795 * * https://html.spec.whatwg.org/multipage/parsing.html#data-state 1796 * * https://html.spec.whatwg.org/multipage/parsing.html#tag-open-state 1797 */ 1798 $tag_name_prefix_length = strspn( $html, 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ', $at + 1 ); 1799 if ( $tag_name_prefix_length > 0 ) { 1800 ++$at; 1801 $this->parser_state = self::STATE_MATCHED_TAG; 1802 $this->tag_name_starts_at = $at; 1803 $this->tag_name_length = $tag_name_prefix_length + strcspn( $html, " \t\f\r\n/>", $at + $tag_name_prefix_length ); 1804 $this->bytes_already_parsed = $at + $this->tag_name_length; 1805 return true; 1806 } 1807 1808 /* 1809 * Abort if no tag is found before the end of 1810 * the document. There is nothing left to parse. 1811 */ 1812 if ( $at + 1 >= $doc_length ) { 1813 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 1814 1815 return false; 1816 } 1817 1818 /* 1819 * `<!` transitions to markup declaration open state 1820 * https://html.spec.whatwg.org/multipage/parsing.html#markup-declaration-open-state 1821 */ 1822 if ( ! $this->is_closing_tag && '!' === $html[ $at + 1 ] ) { 1823 /* 1824 * `<!--` transitions to a comment state – apply further comment rules. 1825 * https://html.spec.whatwg.org/multipage/parsing.html#tag-open-state 1826 */ 1827 if ( 0 === substr_compare( $html, '--', $at + 2, 2 ) ) { 1828 $closer_at = $at + 4; 1829 // If it's not possible to close the comment then there is nothing more to scan. 1830 if ( $doc_length <= $closer_at ) { 1831 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 1832 1833 return false; 1834 } 1835 1836 // Abruptly-closed empty comments are a sequence of dashes followed by `>`. 1837 $span_of_dashes = strspn( $html, '-', $closer_at ); 1838 if ( $doc_length <= $span_of_dashes + $closer_at ) { 1839 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 1840 1841 return false; 1842 } 1843 1844 if ( '>' === $html[ $closer_at + $span_of_dashes ] ) { 1845 /* 1846 * @todo When implementing `set_modifiable_text()` ensure that updates to this token 1847 * don't break the syntax for short comments, e.g. `<!--->`. Unlike other comment 1848 * and bogus comment syntax, these leave no clear insertion point for text and 1849 * they need to be modified specially in order to contain text. E.g. to store 1850 * `?` as the modifiable text, the `<!--->` needs to become `<!--?-->`, which 1851 * involves inserting an additional `-` into the token after the modifiable text. 1852 */ 1853 $this->parser_state = self::STATE_COMMENT; 1854 $this->comment_type = self::COMMENT_AS_ABRUPTLY_CLOSED_COMMENT; 1855 $this->token_length = $closer_at + $span_of_dashes + 1 - $this->token_starts_at; 1856 1857 // Only provide modifiable text if the token is long enough to contain it. 1858 if ( $span_of_dashes >= 2 ) { 1859 $this->comment_type = self::COMMENT_AS_HTML_COMMENT; 1860 $this->text_starts_at = $this->token_starts_at + 4; 1861 $this->text_length = $span_of_dashes - 2; 1862 } 1863 1864 $this->bytes_already_parsed = $closer_at + $span_of_dashes + 1; 1865 return true; 1866 } 1867 1868 /* 1869 * Comments may be closed by either a --> or an invalid --!>. 1870 * The first occurrence closes the comment. 1871 * 1872 * See https://html.spec.whatwg.org/#parse-error-incorrectly-closed-comment 1873 */ 1874 --$closer_at; // Pre-increment inside condition below reduces risk of accidental infinite looping. 1875 while ( ++$closer_at < $doc_length ) { 1876 $closer_at = strpos( $html, '--', $closer_at ); 1877 if ( false === $closer_at ) { 1878 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 1879 1880 return false; 1881 } 1882 1883 if ( $closer_at + 2 < $doc_length && '>' === $html[ $closer_at + 2 ] ) { 1884 $this->parser_state = self::STATE_COMMENT; 1885 $this->comment_type = self::COMMENT_AS_HTML_COMMENT; 1886 $this->token_length = $closer_at + 3 - $this->token_starts_at; 1887 $this->text_starts_at = $this->token_starts_at + 4; 1888 $this->text_length = $closer_at - $this->text_starts_at; 1889 $this->bytes_already_parsed = $closer_at + 3; 1890 return true; 1891 } 1892 1893 if ( 1894 $closer_at + 3 < $doc_length && 1895 '!' === $html[ $closer_at + 2 ] && 1896 '>' === $html[ $closer_at + 3 ] 1897 ) { 1898 $this->parser_state = self::STATE_COMMENT; 1899 $this->comment_type = self::COMMENT_AS_HTML_COMMENT; 1900 $this->token_length = $closer_at + 4 - $this->token_starts_at; 1901 $this->text_starts_at = $this->token_starts_at + 4; 1902 $this->text_length = $closer_at - $this->text_starts_at; 1903 $this->bytes_already_parsed = $closer_at + 4; 1904 return true; 1905 } 1906 } 1907 } 1908 1909 /* 1910 * `<!DOCTYPE` transitions to DOCTYPE state – skip to the nearest > 1911 * These are ASCII-case-insensitive. 1912 * https://html.spec.whatwg.org/multipage/parsing.html#tag-open-state 1913 */ 1914 if ( 1915 $doc_length > $at + 8 && 1916 ( 'D' === $html[ $at + 2 ] || 'd' === $html[ $at + 2 ] ) && 1917 ( 'O' === $html[ $at + 3 ] || 'o' === $html[ $at + 3 ] ) && 1918 ( 'C' === $html[ $at + 4 ] || 'c' === $html[ $at + 4 ] ) && 1919 ( 'T' === $html[ $at + 5 ] || 't' === $html[ $at + 5 ] ) && 1920 ( 'Y' === $html[ $at + 6 ] || 'y' === $html[ $at + 6 ] ) && 1921 ( 'P' === $html[ $at + 7 ] || 'p' === $html[ $at + 7 ] ) && 1922 ( 'E' === $html[ $at + 8 ] || 'e' === $html[ $at + 8 ] ) 1923 ) { 1924 $closer_at = strpos( $html, '>', $at + 9 ); 1925 if ( false === $closer_at ) { 1926 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 1927 1928 return false; 1929 } 1930 1931 $this->parser_state = self::STATE_DOCTYPE; 1932 $this->token_length = $closer_at + 1 - $this->token_starts_at; 1933 $this->text_starts_at = $this->token_starts_at + 9; 1934 $this->text_length = $closer_at - $this->text_starts_at; 1935 $this->bytes_already_parsed = $closer_at + 1; 1936 return true; 1937 } 1938 1939 if ( 1940 'html' !== $this->parsing_namespace && 1941 strlen( $html ) > $at + 8 && 1942 '[' === $html[ $at + 2 ] && 1943 'C' === $html[ $at + 3 ] && 1944 'D' === $html[ $at + 4 ] && 1945 'A' === $html[ $at + 5 ] && 1946 'T' === $html[ $at + 6 ] && 1947 'A' === $html[ $at + 7 ] && 1948 '[' === $html[ $at + 8 ] 1949 ) { 1950 $closer_at = strpos( $html, ']]>', $at + 9 ); 1951 if ( false === $closer_at ) { 1952 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 1953 1954 return false; 1955 } 1956 1957 $this->parser_state = self::STATE_CDATA_NODE; 1958 $this->text_starts_at = $at + 9; 1959 $this->text_length = $closer_at - $this->text_starts_at; 1960 $this->token_length = $closer_at + 3 - $this->token_starts_at; 1961 $this->bytes_already_parsed = $closer_at + 3; 1962 return true; 1963 } 1964 1965 /* 1966 * Anything else here is an incorrectly-opened comment and transitions 1967 * to the bogus comment state - skip to the nearest >. If no closer is 1968 * found then the HTML was truncated inside the markup declaration. 1969 */ 1970 $closer_at = strpos( $html, '>', $at + 1 ); 1971 if ( false === $closer_at ) { 1972 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 1973 1974 return false; 1975 } 1976 1977 $this->parser_state = self::STATE_COMMENT; 1978 $this->comment_type = self::COMMENT_AS_INVALID_HTML; 1979 $this->token_length = $closer_at + 1 - $this->token_starts_at; 1980 $this->text_starts_at = $this->token_starts_at + 2; 1981 $this->text_length = $closer_at - $this->text_starts_at; 1982 $this->bytes_already_parsed = $closer_at + 1; 1983 1984 /* 1985 * Identify nodes that would be CDATA if HTML had CDATA sections. 1986 * 1987 * This section must occur after identifying the bogus comment end 1988 * because in an HTML parser it will span to the nearest `>`, even 1989 * if there's no `]]>` as would be required in an XML document. It 1990 * is therefore not possible to parse a CDATA section containing 1991 * a `>` in the HTML syntax. 1992 * 1993 * Inside foreign elements there is a discrepancy between browsers 1994 * and the specification on this. 1995 * 1996 * @todo Track whether the Tag Processor is inside a foreign element 1997 * and require the proper closing `]]>` in those cases. 1998 */ 1999 if ( 2000 $this->token_length >= 10 && 2001 '[' === $html[ $this->token_starts_at + 2 ] && 2002 'C' === $html[ $this->token_starts_at + 3 ] && 2003 'D' === $html[ $this->token_starts_at + 4 ] && 2004 'A' === $html[ $this->token_starts_at + 5 ] && 2005 'T' === $html[ $this->token_starts_at + 6 ] && 2006 'A' === $html[ $this->token_starts_at + 7 ] && 2007 '[' === $html[ $this->token_starts_at + 8 ] && 2008 ']' === $html[ $closer_at - 1 ] && 2009 ']' === $html[ $closer_at - 2 ] 2010 ) { 2011 $this->parser_state = self::STATE_COMMENT; 2012 $this->comment_type = self::COMMENT_AS_CDATA_LOOKALIKE; 2013 $this->text_starts_at += 7; 2014 $this->text_length -= 9; 2015 } 2016 2017 return true; 2018 } 2019 2020 /* 2021 * </> is a missing end tag name, which is ignored. 2022 * 2023 * This was also known as the "presumptuous empty tag" 2024 * in early discussions as it was proposed to close 2025 * the nearest previous opening tag. 2026 * 2027 * See https://html.spec.whatwg.org/#parse-error-missing-end-tag-name 2028 */ 2029 if ( '>' === $html[ $at + 1 ] ) { 2030 // `<>` is interpreted as plaintext. 2031 if ( ! $this->is_closing_tag ) { 2032 ++$at; 2033 continue; 2034 } 2035 2036 $this->parser_state = self::STATE_PRESUMPTUOUS_TAG; 2037 $this->token_length = $at + 2 - $this->token_starts_at; 2038 $this->bytes_already_parsed = $at + 2; 2039 return true; 2040 } 2041 2042 /** 2043 * `<?` transitions to the processing instruction open state. 2044 * 2045 * A processing instruction whose target starts with an ASCII letter or `_`, 2046 * continues with ASCII alphanumerics, `-`, or `_`, and is not an ASCII 2047 * case-insensitive match for `xml` or `xml-stylesheet` produces a processing 2048 * instruction node. Anything else transitions to the bogus comment state. 2049 * 2050 * Both forms end at the nearest `>`; a processing instruction cannot 2051 * contain one in the HTML syntax. 2052 * 2053 * @link https://html.spec.whatwg.org/multipage/parsing.html#processing-instruction-open-state 2054 */ 2055 if ( ! $this->is_closing_tag && '?' === $html[ $at + 1 ] ) { 2056 $closer_at = strpos( $html, '>', $at + 2 ); 2057 if ( false === $closer_at ) { 2058 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 2059 2060 return false; 2061 } 2062 2063 $target_at = $at + 2; 2064 $target_length = 0; 2065 $first_char = $html[ $target_at ]; 2066 if ( 2067 ( 'a' <= $first_char && 'z' >= $first_char ) || 2068 ( 'A' <= $first_char && 'Z' >= $first_char ) || 2069 '_' === $first_char 2070 ) { 2071 $target_length = 1 + strspn( $html, 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_-', $target_at + 1 ); 2072 } 2073 2074 /* 2075 * In the processing instruction target state, only whitespace, `?`, 2076 * or `>` may terminate the target; any other character converts the 2077 * token into a bogus comment. 2078 * 2079 * The `xml` and `xml-stylesheet` targets are reserved and disallowed; 2080 * they also convert the token into a bogus comment. 2081 */ 2082 $is_valid_pi = ( 2083 0 !== $target_length && 2084 str_contains( " \t\f\r\n?>", $html[ $target_at + $target_length ] ) && 2085 ! ( 3 === $target_length && 0 === substr_compare( $html, 'xml', $target_at, 3, true ) ) && 2086 ! ( 14 === $target_length && 0 === substr_compare( $html, 'xml-stylesheet', $target_at, 14, true ) ) 2087 ); 2088 2089 if ( $is_valid_pi ) { 2090 /* 2091 * The processing instruction data starts after any whitespace 2092 * following the target and ends at the `>`. When the token is 2093 * closed by `?>`, that final `?` is not part of the data. 2094 */ 2095 $data_at = $target_at + $target_length; 2096 $data_at += strspn( $html, " \t\f\r\n", $data_at ); 2097 2098 $data_length = $closer_at - $data_at; 2099 if ( $data_length > 0 && '?' === $html[ $closer_at - 1 ] ) { 2100 --$data_length; 2101 } 2102 2103 $this->parser_state = self::STATE_PROCESSING_INSTRUCTION; 2104 $this->tag_name_starts_at = $target_at; 2105 $this->tag_name_length = $target_length; 2106 $this->token_length = $closer_at + 1 - $this->token_starts_at; 2107 $this->text_starts_at = $data_at; 2108 $this->text_length = $data_length; 2109 $this->bytes_already_parsed = $closer_at + 1; 2110 return true; 2111 } 2112 2113 $this->parser_state = self::STATE_COMMENT; 2114 $this->comment_type = self::COMMENT_AS_INVALID_HTML; 2115 $this->token_length = $closer_at + 1 - $this->token_starts_at; 2116 $this->text_starts_at = $this->token_starts_at + 2; 2117 $this->text_length = $closer_at - $this->text_starts_at; 2118 $this->bytes_already_parsed = $closer_at + 1; 2119 2120 /* 2121 * Identify an XML-like Processing Instruction node. 2122 * 2123 * HTML and XML processing instructions have different parsing rules. 2124 * The HTML API recognizes XML-like processing instructions that are 2125 * _not_ HTML processing instructions. The HTML standard transforms 2126 * them to "bogus comments," represented by the HTML API as comments 2127 * with the `COMMENT_AS_PI_NODE_LOOKALIKE` type. This includes the 2128 * special targets `xml` and `xml-stylesheet` which are reserved 2129 * targets not allowed in HTML processing instructions. 2130 * 2131 * > NameStartChar ::= ":" | [A-Z] | "_" | [a-z] | [#xC0-#xD6] | [#xD8-#xF6] | [#xF8-#x2FF] | 2132 * [#x370-#x37D] | [#x37F-#x1FFF] | [#x200C-#x200D] | [#x2070-#x218F] | 2133 * [#x2C00-#x2FEF] | [#x3001-#xD7FF] | [#xF900-#xFDCF] | [#xFDF0-#xFFFD] | 2134 * [#x10000-#xEFFFF] 2135 * > NameChar ::= NameStartChar | "-" | "." | [0-9] | #xB7 | [#x0300-#x036F] | [#x203F-#x2040] 2136 * 2137 * @see https://www.w3.org/TR/2006/REC-xml11-20060816/#NT-PITarget 2138 */ 2139 if ( $this->token_length >= 5 && '?' === $html[ $closer_at - 1 ] ) { 2140 $comment_text = substr( $html, $this->token_starts_at + 2, $this->token_length - 4 ); 2141 $pi_target_length = strspn( $comment_text, 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ:_' ); 2142 2143 if ( 0 < $pi_target_length ) { 2144 $pi_target_length += strspn( $comment_text, 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789:_-.', $pi_target_length ); 2145 2146 $this->comment_type = self::COMMENT_AS_PI_NODE_LOOKALIKE; 2147 $this->tag_name_starts_at = $this->token_starts_at + 2; 2148 $this->tag_name_length = $pi_target_length; 2149 $this->text_starts_at += $pi_target_length; 2150 $this->text_length -= $pi_target_length + 1; 2151 } 2152 } 2153 2154 return true; 2155 } 2156 2157 /* 2158 * If a non-alpha starts the tag name in a tag closer it's a comment. 2159 * Find the first `>`, which closes the comment. 2160 * 2161 * This parser classifies these particular comments as special "funky comments" 2162 * which are made available for further processing. 2163 * 2164 * See https://html.spec.whatwg.org/#parse-error-invalid-first-character-of-tag-name 2165 */ 2166 if ( $this->is_closing_tag ) { 2167 // No chance of finding a closer. 2168 if ( $at + 3 > $doc_length ) { 2169 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 2170 2171 return false; 2172 } 2173 2174 $closer_at = strpos( $html, '>', $at + 2 ); 2175 if ( false === $closer_at ) { 2176 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 2177 2178 return false; 2179 } 2180 2181 $this->parser_state = self::STATE_FUNKY_COMMENT; 2182 $this->token_length = $closer_at + 1 - $this->token_starts_at; 2183 $this->text_starts_at = $this->token_starts_at + 2; 2184 $this->text_length = $closer_at - $this->text_starts_at; 2185 $this->bytes_already_parsed = $closer_at + 1; 2186 return true; 2187 } 2188 2189 ++$at; 2190 } 2191 2192 /* 2193 * This does not imply an incomplete parse; it indicates that there 2194 * can be nothing left in the document other than a #text node. 2195 */ 2196 $this->parser_state = self::STATE_TEXT_NODE; 2197 $this->token_starts_at = $was_at; 2198 $this->token_length = $doc_length - $was_at; 2199 $this->text_starts_at = $was_at; 2200 $this->text_length = $this->token_length; 2201 $this->bytes_already_parsed = $doc_length; 2202 return true; 2203 } 2204 2205 /** 2206 * Parses the next attribute. 2207 * 2208 * @since 6.2.0 2209 * @ignore 2210 * 2211 * @return bool Whether an attribute was found before the end of the document. 2212 */ 2213 private function parse_next_attribute(): bool { 2214 $doc_length = strlen( $this->html ); 2215 2216 // Skip whitespace and slashes. 2217 $skipped_length = strspn( $this->html, " \t\f\r\n/", $this->bytes_already_parsed ); 2218 $this->bytes_already_parsed += $skipped_length; 2219 if ( $this->bytes_already_parsed >= $doc_length ) { 2220 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 2221 2222 return false; 2223 } 2224 2225 /** 2226 * This block serves two purposes: 2227 * 2228 * - A fast path for common tag-ending `>`. 2229 * - A check for the self-closing flag which must appear as `/>`. 2230 * 2231 * In a tag like `<g attr=/>`, `/` is the attribute value, not a self-closing 2232 * flag. When it appears in this form, the parser has already consumed the 2233 * attribute value, `$skipped_length` is 0, and this checks below correctly 2234 * identify whether there is a self-closing flag. 2235 * 2236 * Note: Both start and end tags may have the self-closing flag. 2237 */ 2238 if ( '>' === $this->html[ $this->bytes_already_parsed ] ) { 2239 if ( $skipped_length > 0 && '/' === $this->html[ $this->bytes_already_parsed - 1 ] ) { 2240 $this->has_self_closing_flag = true; 2241 } 2242 return false; 2243 } 2244 2245 /* 2246 * Treat the equal sign as a part of the attribute 2247 * name if it is the first encountered byte. 2248 * 2249 * @see https://html.spec.whatwg.org/multipage/parsing.html#before-attribute-name-state 2250 */ 2251 $name_length = '=' === $this->html[ $this->bytes_already_parsed ] 2252 ? 1 + strcspn( $this->html, "=/> \t\f\r\n", $this->bytes_already_parsed + 1 ) 2253 : strcspn( $this->html, "=/> \t\f\r\n", $this->bytes_already_parsed ); 2254 2255 // No attribute, just tag closer. 2256 if ( 0 === $name_length || $this->bytes_already_parsed + $name_length >= $doc_length ) { 2257 return false; 2258 } 2259 2260 $attribute_start = $this->bytes_already_parsed; 2261 $attribute_name = substr( $this->html, $attribute_start, $name_length ); 2262 $this->bytes_already_parsed += $name_length; 2263 if ( $this->bytes_already_parsed >= $doc_length ) { 2264 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 2265 2266 return false; 2267 } 2268 2269 $this->skip_whitespace(); 2270 if ( $this->bytes_already_parsed >= $doc_length ) { 2271 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 2272 2273 return false; 2274 } 2275 2276 $has_value = '=' === $this->html[ $this->bytes_already_parsed ]; 2277 if ( $has_value ) { 2278 ++$this->bytes_already_parsed; 2279 $this->skip_whitespace(); 2280 if ( $this->bytes_already_parsed >= $doc_length ) { 2281 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 2282 2283 return false; 2284 } 2285 2286 switch ( $this->html[ $this->bytes_already_parsed ] ) { 2287 case "'": 2288 case '"': 2289 $quote = $this->html[ $this->bytes_already_parsed ]; 2290 $value_start = $this->bytes_already_parsed + 1; 2291 $end_quote_at = strpos( $this->html, $quote, $value_start ); 2292 $end_quote_at = false === $end_quote_at ? $doc_length : $end_quote_at; 2293 $value_length = $end_quote_at - $value_start; 2294 $attribute_end = $end_quote_at + 1; 2295 $this->bytes_already_parsed = $attribute_end; 2296 break; 2297 2298 default: 2299 $value_start = $this->bytes_already_parsed; 2300 $value_length = strcspn( $this->html, "> \t\f\r\n", $value_start ); 2301 $attribute_end = $value_start + $value_length; 2302 $this->bytes_already_parsed = $attribute_end; 2303 } 2304 } else { 2305 $value_start = $this->bytes_already_parsed; 2306 $value_length = 0; 2307 $attribute_end = $attribute_start + $name_length; 2308 } 2309 2310 if ( $attribute_end >= $doc_length ) { 2311 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 2312 2313 return false; 2314 } 2315 2316 if ( $this->is_closing_tag ) { 2317 return true; 2318 } 2319 2320 /* 2321 * > There must never be two or more attributes on 2322 * > the same start tag whose names are an ASCII 2323 * > case-insensitive match for each other. 2324 * - HTML 5 spec 2325 * 2326 * @see https://html.spec.whatwg.org/multipage/syntax.html#attributes-2:ascii-case-insensitive 2327 * 2328 * The tokenizer replaces U+0000 NULL bytes in 2329 * attribute names with U+FFFD. 2330 * 2331 * @see https://html.spec.whatwg.org/#attribute-name-state 2332 */ 2333 $comparable_name = strtolower( str_replace( "\x00", "\u{FFFD}", $attribute_name ) ); 2334 2335 // If an attribute is listed many times, only use the first declaration and ignore the rest. 2336 if ( ! isset( $this->attributes[ $comparable_name ] ) ) { 2337 $this->attributes[ $comparable_name ] = new WP_HTML_Attribute_Token( 2338 $attribute_name, 2339 $value_start, 2340 $value_length, 2341 $attribute_start, 2342 $attribute_end - $attribute_start, 2343 ! $has_value 2344 ); 2345 2346 return true; 2347 } 2348 2349 /* 2350 * Track the duplicate attributes so if we remove it, all disappear together. 2351 * 2352 * While `$this->duplicated_attributes` could always be stored as an `array()`, 2353 * which would simplify the logic here, storing a `null` and only allocating 2354 * an array when encountering duplicates avoids needless allocations in the 2355 * normative case of parsing tags with no duplicate attributes. 2356 */ 2357 $duplicate_span = new WP_HTML_Span( $attribute_start, $attribute_end - $attribute_start ); 2358 if ( null === $this->duplicate_attributes ) { 2359 $this->duplicate_attributes = array( $comparable_name => array( $duplicate_span ) ); 2360 } elseif ( ! isset( $this->duplicate_attributes[ $comparable_name ] ) ) { 2361 $this->duplicate_attributes[ $comparable_name ] = array( $duplicate_span ); 2362 } else { 2363 $this->duplicate_attributes[ $comparable_name ][] = $duplicate_span; 2364 } 2365 2366 return true; 2367 } 2368 2369 /** 2370 * Move the internal cursor past any immediate successive whitespace. 2371 * 2372 * @since 6.2.0 2373 * @ignore 2374 */ 2375 private function skip_whitespace(): void { 2376 $this->bytes_already_parsed += strspn( $this->html, " \t\f\r\n", $this->bytes_already_parsed ); 2377 } 2378 2379 /** 2380 * Applies attribute updates and cleans up once a tag is fully parsed. 2381 * 2382 * @since 6.2.0 2383 * @ignore 2384 */ 2385 private function after_tag(): void { 2386 /* 2387 * There could be lexical updates enqueued for an attribute that 2388 * also exists on the next tag. In order to avoid conflating the 2389 * attributes across the two tags, lexical updates with names 2390 * need to be flushed to raw lexical updates. 2391 */ 2392 $this->class_name_updates_to_attributes_updates(); 2393 2394 /* 2395 * Purge updates if there are too many. The actual count isn't 2396 * scientific, but a few values from 100 to a few thousand were 2397 * tests to find a practically-useful limit. 2398 * 2399 * If the update queue grows too big, then the Tag Processor 2400 * will spend more time iterating through them and lose the 2401 * efficiency gains of deferring applying them. 2402 */ 2403 if ( 1000 < count( $this->lexical_updates ) ) { 2404 $this->get_updated_html(); 2405 } 2406 2407 foreach ( $this->lexical_updates as $name => $update ) { 2408 /* 2409 * Any updates appearing after the cursor should be applied 2410 * before proceeding, otherwise they may be overlooked. 2411 */ 2412 if ( $update->start >= $this->bytes_already_parsed ) { 2413 $this->get_updated_html(); 2414 break; 2415 } 2416 2417 if ( is_int( $name ) ) { 2418 continue; 2419 } 2420 2421 $this->lexical_updates[] = $update; 2422 unset( $this->lexical_updates[ $name ] ); 2423 } 2424 2425 $this->token_starts_at = null; 2426 $this->token_length = null; 2427 $this->has_self_closing_flag = false; 2428 $this->tag_name_starts_at = null; 2429 $this->tag_name_length = null; 2430 $this->text_starts_at = 0; 2431 $this->text_length = 0; 2432 $this->is_closing_tag = null; 2433 $this->attributes = array(); 2434 $this->comment_type = null; 2435 $this->text_node_classification = self::TEXT_IS_GENERIC; 2436 $this->duplicate_attributes = null; 2437 } 2438 2439 /** 2440 * Converts class name updates into tag attributes updates 2441 * (they are accumulated in different data formats for performance). 2442 * 2443 * @since 6.2.0 2444 * @ignore 2445 * 2446 * @see WP_HTML_Tag_Processor::$lexical_updates 2447 * @see WP_HTML_Tag_Processor::$classname_updates 2448 */ 2449 private function class_name_updates_to_attributes_updates(): void { 2450 if ( count( $this->classname_updates ) === 0 ) { 2451 return; 2452 } 2453 2454 $existing_class = $this->get_enqueued_attribute_value( 'class' ); 2455 if ( null === $existing_class || true === $existing_class ) { 2456 $existing_class = ''; 2457 } 2458 2459 if ( false === $existing_class && isset( $this->attributes['class'] ) ) { 2460 $existing_class = $this->get_decoded_attribute_value( $this->attributes['class'] ); 2461 } 2462 2463 if ( false === $existing_class ) { 2464 $existing_class = ''; 2465 } 2466 2467 /** 2468 * Updated "class" attribute value. 2469 * 2470 * This is incrementally built while scanning through the existing class 2471 * attribute, skipping removed classes on the way, and then appending 2472 * added classes at the end. Only when finished processing will the 2473 * value contain the final new value. 2474 2475 * @var string $class 2476 */ 2477 $class = ''; 2478 2479 /** 2480 * Tracks the cursor position in the existing 2481 * class attribute value while parsing. 2482 * 2483 * @var int $at 2484 */ 2485 $at = 0; 2486 2487 /** 2488 * Indicates if there's any need to modify the existing class attribute. 2489 * 2490 * If a call to `add_class()` and `remove_class()` wouldn't impact 2491 * the `class` attribute value then there's no need to rebuild it. 2492 * For example, when adding a class that's already present or 2493 * removing one that isn't. 2494 * 2495 * This flag enables a performance optimization when none of the enqueued 2496 * class updates would impact the `class` attribute; namely, that the 2497 * processor can continue without modifying the input document, as if 2498 * none of the `add_class()` or `remove_class()` calls had been made. 2499 * 2500 * This flag is set upon the first change that requires a string update. 2501 * 2502 * @var bool $modified 2503 */ 2504 $modified = false; 2505 2506 $seen = array(); 2507 $to_remove = array(); 2508 $is_quirks = self::QUIRKS_MODE === $this->compat_mode; 2509 if ( $is_quirks ) { 2510 foreach ( $this->classname_updates as $updated_name => $action ) { 2511 if ( self::REMOVE_CLASS === $action ) { 2512 $to_remove[] = strtolower( $updated_name ); 2513 } 2514 } 2515 } else { 2516 foreach ( $this->classname_updates as $updated_name => $action ) { 2517 if ( self::REMOVE_CLASS === $action ) { 2518 $to_remove[] = $updated_name; 2519 } 2520 } 2521 } 2522 2523 // Remove unwanted classes by only copying the new ones. 2524 $existing_class_length = strlen( $existing_class ); 2525 while ( $at < $existing_class_length ) { 2526 // Skip to the first non-whitespace character. 2527 $ws_at = $at; 2528 $ws_length = strspn( $existing_class, " \t\f\r\n", $ws_at ); 2529 $at += $ws_length; 2530 2531 // Capture the class name – it's everything until the next whitespace. 2532 $name_length = strcspn( $existing_class, " \t\f\r\n", $at ); 2533 if ( 0 === $name_length ) { 2534 // If no more class names are found then that's the end. 2535 break; 2536 } 2537 2538 $name = substr( $existing_class, $at, $name_length ); 2539 $comparable_class_name = $is_quirks ? strtolower( $name ) : $name; 2540 $at += $name_length; 2541 2542 // If this class is marked for removal, remove it and move on to the next one. 2543 if ( in_array( $comparable_class_name, $to_remove, true ) ) { 2544 $modified = true; 2545 continue; 2546 } 2547 2548 // If a class has already been seen then skip it; it should not be added twice. 2549 if ( in_array( $comparable_class_name, $seen, true ) ) { 2550 continue; 2551 } 2552 2553 $seen[] = $comparable_class_name; 2554 2555 /* 2556 * Otherwise, append it to the new "class" attribute value. 2557 * 2558 * There are options for handling whitespace between tags. 2559 * Preserving the existing whitespace produces fewer changes 2560 * to the HTML content and should clarify the before/after 2561 * content when debugging the modified output. 2562 * 2563 * This approach contrasts normalizing the inter-class 2564 * whitespace to a single space, which might appear cleaner 2565 * in the output HTML but produce a noisier change. 2566 */ 2567 if ( '' !== $class ) { 2568 $class .= substr( $existing_class, $ws_at, $ws_length ); 2569 } 2570 $class .= $name; 2571 } 2572 2573 // Add new classes by appending those which haven't already been seen. 2574 foreach ( $this->classname_updates as $name => $operation ) { 2575 $comparable_name = $is_quirks ? strtolower( $name ) : $name; 2576 if ( self::ADD_CLASS === $operation && ! in_array( $comparable_name, $seen, true ) ) { 2577 $modified = true; 2578 2579 $class .= strlen( $class ) > 0 ? ' ' : ''; 2580 $class .= $name; 2581 } 2582 } 2583 2584 $this->classname_updates = array(); 2585 if ( ! $modified ) { 2586 return; 2587 } 2588 2589 if ( strlen( $class ) > 0 ) { 2590 $this->set_attribute( 'class', $class ); 2591 } else { 2592 $this->remove_attribute( 'class' ); 2593 } 2594 } 2595 2596 /** 2597 * Applies attribute updates to HTML document. 2598 * 2599 * @since 6.2.0 2600 * @since 6.2.1 Accumulates shift for internal cursor and passed pointer. 2601 * @since 6.3.0 Invalidate any bookmarks whose targets are overwritten. 2602 * @ignore 2603 * 2604 * @param int $shift_this_point Accumulate and return shift for this position. 2605 * @return int How many bytes the given pointer moved in response to the updates. 2606 */ 2607 private function apply_attributes_updates( int $shift_this_point ): int { 2608 if ( ! count( $this->lexical_updates ) ) { 2609 return 0; 2610 } 2611 2612 $accumulated_shift_for_given_point = 0; 2613 2614 /* 2615 * Attribute updates can be enqueued in any order but updates 2616 * to the document must occur in lexical order; that is, each 2617 * replacement must be made before all others which follow it 2618 * at later string indices in the input document. 2619 * 2620 * Sorting avoids making out-of-order replacements which 2621 * can lead to mangled output, partially-duplicated 2622 * attributes, and overwritten attributes. 2623 */ 2624 usort( $this->lexical_updates, array( self::class, 'sort_start_ascending' ) ); 2625 2626 $bytes_already_copied = 0; 2627 $output_buffer = ''; 2628 foreach ( $this->lexical_updates as $diff ) { 2629 $shift = strlen( $diff->text ) - $diff->length; 2630 2631 // Adjust the cursor position by however much an update affects it. 2632 if ( $diff->start < $this->bytes_already_parsed ) { 2633 $this->bytes_already_parsed += $shift; 2634 } 2635 2636 // Accumulate shift of the given pointer within this function call. 2637 if ( $diff->start < $shift_this_point ) { 2638 $accumulated_shift_for_given_point += $shift; 2639 } 2640 2641 $output_buffer .= substr( $this->html, $bytes_already_copied, $diff->start - $bytes_already_copied ); 2642 $output_buffer .= $diff->text; 2643 $bytes_already_copied = $diff->start + $diff->length; 2644 } 2645 2646 $this->html = $output_buffer . substr( $this->html, $bytes_already_copied ); 2647 2648 /* 2649 * Adjust bookmark locations to account for how the text 2650 * replacements adjust offsets in the input document. 2651 */ 2652 foreach ( $this->bookmarks as $bookmark_name => $bookmark ) { 2653 $bookmark_end = $bookmark->start + $bookmark->length; 2654 2655 /* 2656 * Each lexical update which appears before the bookmark's endpoints 2657 * might shift the offsets for those endpoints. Loop through each change 2658 * and accumulate the total shift for each bookmark, then apply that 2659 * shift after tallying the full delta. 2660 */ 2661 $head_delta = 0; 2662 $tail_delta = 0; 2663 2664 foreach ( $this->lexical_updates as $diff ) { 2665 $diff_end = $diff->start + $diff->length; 2666 2667 if ( $bookmark->start < $diff->start && $bookmark_end < $diff->start ) { 2668 break; 2669 } 2670 2671 if ( $bookmark->start >= $diff->start && $bookmark_end < $diff_end ) { 2672 $this->release_bookmark( $bookmark_name ); 2673 continue 2; 2674 } 2675 2676 $delta = strlen( $diff->text ) - $diff->length; 2677 2678 if ( $bookmark->start >= $diff->start ) { 2679 $head_delta += $delta; 2680 } 2681 2682 if ( $bookmark_end >= $diff_end ) { 2683 $tail_delta += $delta; 2684 } 2685 } 2686 2687 $bookmark->start += $head_delta; 2688 $bookmark->length += $tail_delta - $head_delta; 2689 } 2690 2691 $this->lexical_updates = array(); 2692 2693 return $accumulated_shift_for_given_point; 2694 } 2695 2696 /** 2697 * Checks whether a bookmark with the given name exists. 2698 * 2699 * @since 6.3.0 2700 * 2701 * @param string $bookmark_name Name to identify a bookmark that potentially exists. 2702 * @return bool Whether that bookmark exists. 2703 */ 2704 public function has_bookmark( $bookmark_name ): bool { 2705 return array_key_exists( $bookmark_name, $this->bookmarks ); 2706 } 2707 2708 /** 2709 * Move the internal cursor in the Tag Processor to a given bookmark's location. 2710 * 2711 * In order to prevent accidental infinite loops, there's a 2712 * maximum limit on the number of times seek() can be called. 2713 * 2714 * @since 6.2.0 2715 * 2716 * @param string $bookmark_name Jump to the place in the document identified by this bookmark name. 2717 * @return bool Whether the internal cursor was successfully moved to the bookmark's location. 2718 */ 2719 public function seek( $bookmark_name ): bool { 2720 if ( ! array_key_exists( $bookmark_name, $this->bookmarks ) ) { 2721 _doing_it_wrong( 2722 __METHOD__, 2723 __( 'Unknown bookmark name.' ), 2724 '6.2.0' 2725 ); 2726 return false; 2727 } 2728 2729 $existing_bookmark = $this->bookmarks[ $bookmark_name ]; 2730 2731 if ( 2732 $this->token_starts_at === $existing_bookmark->start && 2733 $this->token_length === $existing_bookmark->length 2734 ) { 2735 return true; 2736 } 2737 2738 if ( ++$this->seek_count > static::MAX_SEEK_OPS ) { 2739 _doing_it_wrong( 2740 __METHOD__, 2741 __( 'Too many calls to seek() - this can lead to performance issues.' ), 2742 '6.2.0' 2743 ); 2744 return false; 2745 } 2746 2747 // Flush out any pending updates to the document. 2748 $this->get_updated_html(); 2749 2750 // Point this tag processor before the sought tag opener and consume it. 2751 $this->bytes_already_parsed = $this->bookmarks[ $bookmark_name ]->start; 2752 $this->parser_state = self::STATE_READY; 2753 return $this->next_token(); 2754 } 2755 2756 /** 2757 * Compare two WP_HTML_Text_Replacement objects. 2758 * 2759 * @since 6.2.0 2760 * @ignore 2761 * 2762 * @param WP_HTML_Text_Replacement $a First attribute update. 2763 * @param WP_HTML_Text_Replacement $b Second attribute update. 2764 * @return int Comparison value for string order. 2765 */ 2766 private static function sort_start_ascending( WP_HTML_Text_Replacement $a, WP_HTML_Text_Replacement $b ): int { 2767 $by_start = $a->start - $b->start; 2768 if ( 0 !== $by_start ) { 2769 return $by_start; 2770 } 2771 2772 $by_text = isset( $a->text, $b->text ) ? strcmp( $a->text, $b->text ) : 0; 2773 if ( 0 !== $by_text ) { 2774 return $by_text; 2775 } 2776 2777 /* 2778 * This code should be unreachable, because it implies the two replacements 2779 * start at the same location and contain the same text. 2780 */ 2781 return $a->length - $b->length; 2782 } 2783 2784 /** 2785 * Return the enqueued value for a given attribute, if one exists. 2786 * 2787 * Enqueued updates can take different data types: 2788 * - If an update is enqueued and is boolean, the return will be `true` 2789 * - If an update is otherwise enqueued, the return will be the string value of that update. 2790 * - If an attribute is enqueued to be removed, the return will be `null` to indicate that. 2791 * - If no updates are enqueued, the return will be `false` to differentiate from "removed." 2792 * 2793 * @since 6.2.0 2794 * @ignore 2795 * 2796 * @param string $comparable_name The attribute name in its comparable form. 2797 * @return string|boolean|null Value of enqueued update if present, otherwise false. 2798 */ 2799 private function get_enqueued_attribute_value( string $comparable_name ) { 2800 if ( self::STATE_MATCHED_TAG !== $this->parser_state ) { 2801 return false; 2802 } 2803 2804 if ( ! isset( $this->lexical_updates[ $comparable_name ] ) ) { 2805 return false; 2806 } 2807 2808 $enqueued_text = $this->lexical_updates[ $comparable_name ]->text; 2809 2810 // Removed attributes erase the entire span. 2811 if ( '' === $enqueued_text ) { 2812 return null; 2813 } 2814 2815 /* 2816 * Boolean attribute updates are just the attribute name without a corresponding value. 2817 * 2818 * This value might differ from the given comparable name in that there could be leading 2819 * or trailing whitespace, and that the casing follows the name given in `set_attribute`. 2820 * 2821 * Example: 2822 * 2823 * $p->set_attribute( 'data-TEST-id', 'update' ); 2824 * 'update' === $p->get_enqueued_attribute_value( 'data-test-id' ); 2825 * 2826 * Detect this difference based on the absence of the `=`, which _must_ exist in any 2827 * attribute containing a value, e.g. `<input type="text" enabled />`. 2828 * ¹ ² 2829 * 1. Attribute with a string value. 2830 * 2. Boolean attribute whose value is `true`. 2831 */ 2832 $equals_at = strpos( $enqueued_text, '=' ); 2833 if ( false === $equals_at ) { 2834 return true; 2835 } 2836 2837 /* 2838 * Finally, a normal update's value will appear after the `=` and 2839 * be double-quoted, as performed incidentally by `set_attribute`. 2840 * 2841 * e.g. `type="text"` 2842 * ¹² ³ 2843 * 1. Equals is here. 2844 * 2. Double-quoting starts one after the equals sign. 2845 * 3. Double-quoting ends at the last character in the update. 2846 */ 2847 $enqueued_value = substr( $enqueued_text, $equals_at + 2, -1 ); 2848 return WP_HTML_Decoder::decode_attribute( $enqueued_value ); 2849 } 2850 2851 /** 2852 * Returns the value of a requested attribute from a matched tag opener if that attribute exists. 2853 * 2854 * Example: 2855 * 2856 * $p = new WP_HTML_Tag_Processor( '<div enabled class="test" data-test-id="14">Test</div>' ); 2857 * $p->next_tag( array( 'class_name' => 'test' ) ) === true; 2858 * $p->get_attribute( 'data-test-id' ) === '14'; 2859 * $p->get_attribute( 'enabled' ) === true; 2860 * $p->get_attribute( 'aria-label' ) === null; 2861 * 2862 * $p->next_tag() === false; 2863 * $p->get_attribute( 'class' ) === null; 2864 * 2865 * @since 6.2.0 2866 * 2867 * @param string $name Name of attribute whose value is requested. 2868 * @return string|true|null Value of attribute or `null` if not available. Boolean attributes return `true`. 2869 */ 2870 public function get_attribute( $name ) { 2871 if ( self::STATE_MATCHED_TAG !== $this->parser_state ) { 2872 return null; 2873 } 2874 2875 $comparable = strtolower( $name ); 2876 2877 /* 2878 * For every attribute other than `class` it's possible to perform a quick check if 2879 * there's an enqueued lexical update whose value takes priority over what's found in 2880 * the input document. 2881 * 2882 * The `class` attribute is special though because of the exposed helpers `add_class` 2883 * and `remove_class`. These form a builder for the `class` attribute, so an additional 2884 * check for enqueued class changes is required in addition to the check for any enqueued 2885 * attribute values. If any exist, those enqueued class changes must first be flushed out 2886 * into an attribute value update. 2887 */ 2888 if ( 'class' === $comparable ) { 2889 $this->class_name_updates_to_attributes_updates(); 2890 } 2891 2892 // Return any enqueued attribute value updates if they exist. 2893 $enqueued_value = $this->get_enqueued_attribute_value( $comparable ); 2894 if ( false !== $enqueued_value ) { 2895 return $enqueued_value; 2896 } 2897 2898 if ( ! isset( $this->attributes[ $comparable ] ) ) { 2899 return null; 2900 } 2901 2902 $attribute = $this->attributes[ $comparable ]; 2903 2904 /* 2905 * This flag distinguishes an attribute with no value 2906 * from an attribute with an empty string value. For 2907 * unquoted attributes this could look very similar. 2908 * It refers to whether an `=` follows the name. 2909 * 2910 * e.g. <div boolean-attribute empty-attribute=></div> 2911 * ¹ ² 2912 * 1. Attribute `boolean-attribute` is `true`. 2913 * 2. Attribute `empty-attribute` is `""`. 2914 */ 2915 if ( true === $attribute->is_true ) { 2916 return true; 2917 } 2918 2919 return $this->get_decoded_attribute_value( $attribute ); 2920 } 2921 2922 /** 2923 * Decode an attribute value from source. 2924 * 2925 * This method applies the following transformations that the processor defers: 2926 * - Normalize newlines (input stream preprocessing) 2927 * - Replace NULL bytes (tokenization) 2928 * - Decode character references (tokenization) 2929 * 2930 * @since 7.1.0 2931 * @ignore 2932 * 2933 * @param WP_HTML_Attribute_Token $attribute Attribute token from the input document. 2934 * @return string Decoded attribute value. 2935 */ 2936 private function get_decoded_attribute_value( WP_HTML_Attribute_Token $attribute ): string { 2937 $raw_value = substr( $this->html, $attribute->value_starts_at, $attribute->value_length ); 2938 $raw_value = str_replace( "\r\n", "\n", $raw_value ); 2939 $raw_value = str_replace( "\r", "\n", $raw_value ); 2940 $raw_value = str_replace( "\x00", "\u{FFFD}", $raw_value ); 2941 return WP_HTML_Decoder::decode_attribute( $raw_value ); 2942 } 2943 2944 /** 2945 * Gets lowercase names of all attributes matching a given prefix in the current tag. 2946 * 2947 * Note that matching is case-insensitive. This is in accordance with the spec: 2948 * 2949 * > There must never be two or more attributes on 2950 * > the same start tag whose names are an ASCII 2951 * > case-insensitive match for each other. 2952 * - HTML 5 spec 2953 * 2954 * Example: 2955 * 2956 * $p = new WP_HTML_Tag_Processor( '<div data-ENABLED class="test" DATA-test-id="14">Test</div>' ); 2957 * $p->next_tag( array( 'class_name' => 'test' ) ) === true; 2958 * $p->get_attribute_names_with_prefix( 'data-' ) === array( 'data-enabled', 'data-test-id' ); 2959 * 2960 * $p->next_tag() === false; 2961 * $p->get_attribute_names_with_prefix( 'data-' ) === null; 2962 * 2963 * @since 6.2.0 2964 * 2965 * @see https://html.spec.whatwg.org/multipage/syntax.html#attributes-2:ascii-case-insensitive 2966 * 2967 * @param string $prefix Prefix of requested attribute names. 2968 * @return array|null List of attribute names, or `null` when no tag opener is matched. 2969 * @phpstan-return list<non-empty-string>|null 2970 */ 2971 public function get_attribute_names_with_prefix( $prefix ): ?array { 2972 if ( 2973 self::STATE_MATCHED_TAG !== $this->parser_state || 2974 $this->is_closing_tag 2975 ) { 2976 return null; 2977 } 2978 2979 $comparable = strtolower( $prefix ); 2980 2981 /* 2982 * For the `class` attribute, ensure that enqueued class changes from 2983 * `add_class` and `remove_class` are flushed into attribute updates. 2984 */ 2985 $has_class = isset( $this->attributes['class'] ); 2986 if ( '' === $comparable || str_starts_with( 'class', $comparable ) ) { 2987 foreach ( $this->classname_updates as $update ) { 2988 if ( 2989 ( $has_class && self::REMOVE_CLASS === $update ) || 2990 ( ! $has_class && self::ADD_CLASS === $update ) 2991 ) { 2992 $this->class_name_updates_to_attributes_updates(); 2993 break; 2994 } 2995 } 2996 } 2997 2998 $additions = array(); 2999 $removals = array(); 3000 foreach ( $this->lexical_updates as $update_name => $update ) { 3001 if ( is_int( $update_name ) || 'modifiable text' === $update_name ) { 3002 continue; 3003 } 3004 3005 if ( '' === $update->text ) { 3006 $removals[ $update_name ] = true; 3007 } elseif ( ! isset( $this->attributes[ $update_name ] ) && str_starts_with( $update_name, $comparable ) ) { 3008 $additions[] = $update_name; 3009 } 3010 } 3011 3012 $matches = array(); 3013 foreach ( array_keys( $this->attributes ) as $attr_name ) { 3014 if ( str_starts_with( $attr_name, $comparable ) && ! isset( $removals[ $attr_name ] ) ) { 3015 $matches[] = $attr_name; 3016 } 3017 } 3018 3019 return empty( $additions ) ? $matches : array_merge( $additions, $matches ); 3020 } 3021 3022 /** 3023 * Returns the namespace of the matched token. 3024 * 3025 * @since 6.7.0 3026 * 3027 * @return string One of 'html', 'math', or 'svg'. 3028 */ 3029 public function get_namespace(): string { 3030 return $this->parsing_namespace; 3031 } 3032 3033 /** 3034 * Returns the uppercase name of the matched tag. 3035 * 3036 * Example: 3037 * 3038 * $p = new WP_HTML_Tag_Processor( '<div class="test">Test</div>' ); 3039 * $p->next_tag() === true; 3040 * $p->get_tag() === 'DIV'; 3041 * 3042 * $p->next_tag() === false; 3043 * $p->get_tag() === null; 3044 * 3045 * @since 6.2.0 3046 * 3047 * @return string|null Name of currently matched tag in input HTML, or `null` if none found. 3048 */ 3049 public function get_tag(): ?string { 3050 if ( null === $this->tag_name_starts_at ) { 3051 return null; 3052 } 3053 3054 $tag_name = str_replace( "\x00", "\u{FFFD}", substr( $this->html, $this->tag_name_starts_at, $this->tag_name_length ) ); 3055 3056 if ( self::STATE_MATCHED_TAG === $this->parser_state ) { 3057 return strtoupper( $tag_name ); 3058 } 3059 3060 /* 3061 * Processing instruction targets are case-sensitive 3062 * and returned as they appear in the input HTML. 3063 */ 3064 if ( self::STATE_PROCESSING_INSTRUCTION === $this->parser_state ) { 3065 return $tag_name; 3066 } 3067 3068 if ( 3069 self::STATE_COMMENT === $this->parser_state && 3070 self::COMMENT_AS_PI_NODE_LOOKALIKE === $this->get_comment_type() 3071 ) { 3072 return $tag_name; 3073 } 3074 3075 return null; 3076 } 3077 3078 /** 3079 * Returns the adjusted tag name for a given token, taking into 3080 * account the current parsing context, whether HTML, SVG, or MathML. 3081 * 3082 * @since 6.7.0 3083 * 3084 * @return string|null Name of current tag name. 3085 */ 3086 public function get_qualified_tag_name(): ?string { 3087 $tag_name = $this->get_tag(); 3088 if ( null === $tag_name ) { 3089 return null; 3090 } 3091 3092 if ( 'html' === $this->get_namespace() ) { 3093 return $tag_name; 3094 } 3095 3096 $lower_tag_name = strtolower( $tag_name ); 3097 if ( 'math' === $this->get_namespace() ) { 3098 return $lower_tag_name; 3099 } 3100 3101 if ( 'svg' === $this->get_namespace() ) { 3102 switch ( $lower_tag_name ) { 3103 case 'altglyph': 3104 return 'altGlyph'; 3105 3106 case 'altglyphdef': 3107 return 'altGlyphDef'; 3108 3109 case 'altglyphitem': 3110 return 'altGlyphItem'; 3111 3112 case 'animatecolor': 3113 return 'animateColor'; 3114 3115 case 'animatemotion': 3116 return 'animateMotion'; 3117 3118 case 'animatetransform': 3119 return 'animateTransform'; 3120 3121 case 'clippath': 3122 return 'clipPath'; 3123 3124 case 'feblend': 3125 return 'feBlend'; 3126 3127 case 'fecolormatrix': 3128 return 'feColorMatrix'; 3129 3130 case 'fecomponenttransfer': 3131 return 'feComponentTransfer'; 3132 3133 case 'fecomposite': 3134 return 'feComposite'; 3135 3136 case 'feconvolvematrix': 3137 return 'feConvolveMatrix'; 3138 3139 case 'fediffuselighting': 3140 return 'feDiffuseLighting'; 3141 3142 case 'fedisplacementmap': 3143 return 'feDisplacementMap'; 3144 3145 case 'fedistantlight': 3146 return 'feDistantLight'; 3147 3148 case 'fedropshadow': 3149 return 'feDropShadow'; 3150 3151 case 'feflood': 3152 return 'feFlood'; 3153 3154 case 'fefunca': 3155 return 'feFuncA'; 3156 3157 case 'fefuncb': 3158 return 'feFuncB'; 3159 3160 case 'fefuncg': 3161 return 'feFuncG'; 3162 3163 case 'fefuncr': 3164 return 'feFuncR'; 3165 3166 case 'fegaussianblur': 3167 return 'feGaussianBlur'; 3168 3169 case 'feimage': 3170 return 'feImage'; 3171 3172 case 'femerge': 3173 return 'feMerge'; 3174 3175 case 'femergenode': 3176 return 'feMergeNode'; 3177 3178 case 'femorphology': 3179 return 'feMorphology'; 3180 3181 case 'feoffset': 3182 return 'feOffset'; 3183 3184 case 'fepointlight': 3185 return 'fePointLight'; 3186 3187 case 'fespecularlighting': 3188 return 'feSpecularLighting'; 3189 3190 case 'fespotlight': 3191 return 'feSpotLight'; 3192 3193 case 'fetile': 3194 return 'feTile'; 3195 3196 case 'feturbulence': 3197 return 'feTurbulence'; 3198 3199 case 'foreignobject': 3200 return 'foreignObject'; 3201 3202 case 'glyphref': 3203 return 'glyphRef'; 3204 3205 case 'lineargradient': 3206 return 'linearGradient'; 3207 3208 case 'radialgradient': 3209 return 'radialGradient'; 3210 3211 case 'textpath': 3212 return 'textPath'; 3213 3214 default: 3215 return $lower_tag_name; 3216 } 3217 } 3218 3219 // This unnecessary return prevents tools from inaccurately reporting type errors. 3220 return $tag_name; 3221 } 3222 3223 /** 3224 * Returns the adjusted attribute name for a given attribute, taking into 3225 * account the current parsing context, whether HTML, SVG, or MathML. 3226 * 3227 * In SVG and MathML contexts, adjusted foreign attributes with a namespace 3228 * prefix use a space between the prefix and local name. For example, 3229 * `xlink:href` is returned as `xlink href`, while the unprefixed `xmlns` 3230 * attribute is returned as `xmlns`. Non-adjusted attributes with a colon in 3231 * their name, such as `foo:bar`, are returned unchanged. 3232 * 3233 * @since 6.7.0 3234 * 3235 * @param string $attribute_name Which attribute to adjust. 3236 * @return string|null 3237 */ 3238 public function get_qualified_attribute_name( $attribute_name ): ?string { 3239 if ( self::STATE_MATCHED_TAG !== $this->parser_state ) { 3240 return null; 3241 } 3242 3243 $namespace = $this->get_namespace(); 3244 $lower_name = strtolower( $attribute_name ); 3245 3246 if ( 'math' === $namespace && 'definitionurl' === $lower_name ) { 3247 return 'definitionURL'; 3248 } 3249 3250 if ( 'svg' === $this->get_namespace() ) { 3251 switch ( $lower_name ) { 3252 case 'attributename': 3253 return 'attributeName'; 3254 3255 case 'attributetype': 3256 return 'attributeType'; 3257 3258 case 'basefrequency': 3259 return 'baseFrequency'; 3260 3261 case 'baseprofile': 3262 return 'baseProfile'; 3263 3264 case 'calcmode': 3265 return 'calcMode'; 3266 3267 case 'clippathunits': 3268 return 'clipPathUnits'; 3269 3270 case 'diffuseconstant': 3271 return 'diffuseConstant'; 3272 3273 case 'edgemode': 3274 return 'edgeMode'; 3275 3276 case 'filterunits': 3277 return 'filterUnits'; 3278 3279 case 'glyphref': 3280 return 'glyphRef'; 3281 3282 case 'gradienttransform': 3283 return 'gradientTransform'; 3284 3285 case 'gradientunits': 3286 return 'gradientUnits'; 3287 3288 case 'kernelmatrix': 3289 return 'kernelMatrix'; 3290 3291 case 'kernelunitlength': 3292 return 'kernelUnitLength'; 3293 3294 case 'keypoints': 3295 return 'keyPoints'; 3296 3297 case 'keysplines': 3298 return 'keySplines'; 3299 3300 case 'keytimes': 3301 return 'keyTimes'; 3302 3303 case 'lengthadjust': 3304 return 'lengthAdjust'; 3305 3306 case 'limitingconeangle': 3307 return 'limitingConeAngle'; 3308 3309 case 'markerheight': 3310 return 'markerHeight'; 3311 3312 case 'markerunits': 3313 return 'markerUnits'; 3314 3315 case 'markerwidth': 3316 return 'markerWidth'; 3317 3318 case 'maskcontentunits': 3319 return 'maskContentUnits'; 3320 3321 case 'maskunits': 3322 return 'maskUnits'; 3323 3324 case 'numoctaves': 3325 return 'numOctaves'; 3326 3327 case 'pathlength': 3328 return 'pathLength'; 3329 3330 case 'patterncontentunits': 3331 return 'patternContentUnits'; 3332 3333 case 'patterntransform': 3334 return 'patternTransform'; 3335 3336 case 'patternunits': 3337 return 'patternUnits'; 3338 3339 case 'pointsatx': 3340 return 'pointsAtX'; 3341 3342 case 'pointsaty': 3343 return 'pointsAtY'; 3344 3345 case 'pointsatz': 3346 return 'pointsAtZ'; 3347 3348 case 'preservealpha': 3349 return 'preserveAlpha'; 3350 3351 case 'preserveaspectratio': 3352 return 'preserveAspectRatio'; 3353 3354 case 'primitiveunits': 3355 return 'primitiveUnits'; 3356 3357 case 'refx': 3358 return 'refX'; 3359 3360 case 'refy': 3361 return 'refY'; 3362 3363 case 'repeatcount': 3364 return 'repeatCount'; 3365 3366 case 'repeatdur': 3367 return 'repeatDur'; 3368 3369 case 'requiredextensions': 3370 return 'requiredExtensions'; 3371 3372 case 'requiredfeatures': 3373 return 'requiredFeatures'; 3374 3375 case 'specularconstant': 3376 return 'specularConstant'; 3377 3378 case 'specularexponent': 3379 return 'specularExponent'; 3380 3381 case 'spreadmethod': 3382 return 'spreadMethod'; 3383 3384 case 'startoffset': 3385 return 'startOffset'; 3386 3387 case 'stddeviation': 3388 return 'stdDeviation'; 3389 3390 case 'stitchtiles': 3391 return 'stitchTiles'; 3392 3393 case 'surfacescale': 3394 return 'surfaceScale'; 3395 3396 case 'systemlanguage': 3397 return 'systemLanguage'; 3398 3399 case 'tablevalues': 3400 return 'tableValues'; 3401 3402 case 'targetx': 3403 return 'targetX'; 3404 3405 case 'targety': 3406 return 'targetY'; 3407 3408 case 'textlength': 3409 return 'textLength'; 3410 3411 case 'viewbox': 3412 return 'viewBox'; 3413 3414 case 'viewtarget': 3415 return 'viewTarget'; 3416 3417 case 'xchannelselector': 3418 return 'xChannelSelector'; 3419 3420 case 'ychannelselector': 3421 return 'yChannelSelector'; 3422 3423 case 'zoomandpan': 3424 return 'zoomAndPan'; 3425 } 3426 } 3427 3428 if ( 'html' !== $namespace ) { 3429 switch ( $lower_name ) { 3430 case 'xlink:actuate': 3431 return 'xlink actuate'; 3432 3433 case 'xlink:arcrole': 3434 return 'xlink arcrole'; 3435 3436 case 'xlink:href': 3437 return 'xlink href'; 3438 3439 case 'xlink:role': 3440 return 'xlink role'; 3441 3442 case 'xlink:show': 3443 return 'xlink show'; 3444 3445 case 'xlink:title': 3446 return 'xlink title'; 3447 3448 case 'xlink:type': 3449 return 'xlink type'; 3450 3451 case 'xml:lang': 3452 return 'xml lang'; 3453 3454 case 'xml:space': 3455 return 'xml space'; 3456 3457 case 'xmlns': 3458 return 'xmlns'; 3459 3460 case 'xmlns:xlink': 3461 return 'xmlns xlink'; 3462 } 3463 } 3464 3465 return $attribute_name; 3466 } 3467 3468 /** 3469 * Indicates if the currently matched tag contains the self-closing flag. 3470 * 3471 * No HTML elements ought to have the self-closing flag and for those, the self-closing 3472 * flag will be ignored. For void elements this is benign because they "self close" 3473 * automatically. For non-void HTML elements though problems will appear if someone 3474 * intends to use a self-closing element in place of that element with an empty body. 3475 * For HTML foreign elements and custom elements the self-closing flag determines if 3476 * they self-close or not. 3477 * 3478 * This function does not determine if a tag is self-closing, 3479 * but only if the self-closing flag is present in the syntax. 3480 * 3481 * @since 6.3.0 3482 * 3483 * @return bool Whether the currently matched tag contains the self-closing flag. 3484 */ 3485 public function has_self_closing_flag(): bool { 3486 if ( self::STATE_MATCHED_TAG !== $this->parser_state ) { 3487 return false; 3488 } 3489 3490 return $this->has_self_closing_flag; 3491 } 3492 3493 /** 3494 * Indicates if the current tag token is a tag closer. 3495 * 3496 * Example: 3497 * 3498 * $p = new WP_HTML_Tag_Processor( '<div></div>' ); 3499 * $p->next_tag( array( 'tag_name' => 'div', 'tag_closers' => 'visit' ) ); 3500 * $p->is_tag_closer() === false; 3501 * 3502 * $p->next_tag( array( 'tag_name' => 'div', 'tag_closers' => 'visit' ) ); 3503 * $p->is_tag_closer() === true; 3504 * 3505 * @since 6.2.0 3506 * @since 6.7.0 Reports all BR tags as opening tags. 3507 * 3508 * @return bool Whether the current tag is a tag closer. 3509 */ 3510 public function is_tag_closer(): bool { 3511 return ( 3512 self::STATE_MATCHED_TAG === $this->parser_state && 3513 $this->is_closing_tag && 3514 3515 /* 3516 * The BR tag can only exist as an opening tag. If something like `</br>` 3517 * appears then the HTML parser will treat it as an opening tag with no 3518 * attributes. The BR tag is unique in this way. 3519 * 3520 * @see https://html.spec.whatwg.org/#parsing-main-inbody 3521 */ 3522 'BR' !== $this->get_tag() 3523 ); 3524 } 3525 3526 /** 3527 * Indicates the kind of matched token, if any. 3528 * 3529 * This differs from `get_token_name()` in that it always 3530 * returns a static string indicating the type, whereas 3531 * `get_token_name()` may return values derived from the 3532 * token itself, such as a tag name or processing 3533 * instruction tag. 3534 * 3535 * Possible values: 3536 * - `#tag` when matched on a tag. 3537 * - `#text` when matched on a text node. 3538 * - `#cdata-section` when matched on a CDATA node. 3539 * - `#comment` when matched on a comment. 3540 * - `#doctype` when matched on a DOCTYPE declaration. 3541 * - `#presumptuous-tag` when matched on an empty tag closer. 3542 * - `#funky-comment` when matched on a funky comment. 3543 * - `#processing-instruction` when matched on a processing instruction. 3544 * 3545 * @since 6.5.0 3546 * @since 7.1.0 Recognizes processing instructions. 3547 * 3548 * @return string|null What kind of token is matched, or null. 3549 * @phpstan-return '#tag'|'#text'|'#cdata-section'|'#comment'|'#doctype'|'#presumptuous-tag'|'#funky-comment'|'#processing-instruction'|null 3550 */ 3551 public function get_token_type(): ?string { 3552 switch ( $this->parser_state ) { 3553 case self::STATE_MATCHED_TAG: 3554 return '#tag'; 3555 3556 case self::STATE_DOCTYPE: 3557 return '#doctype'; 3558 3559 default: 3560 return $this->get_token_name(); 3561 } 3562 } 3563 3564 /** 3565 * Returns the node name represented by the token. 3566 * 3567 * This matches the DOM API value `nodeName`. Some values 3568 * are static, such as `#text` for a text node, while others 3569 * are dynamically generated from the token itself. 3570 * 3571 * Dynamic names: 3572 * - Uppercase tag name for tag matches. 3573 * - `html` for DOCTYPE declarations. 3574 * 3575 * Note that if the Tag Processor is not matched on a token 3576 * then this function will return `null`, either because it 3577 * hasn't yet found a token or because it reached the end 3578 * of the document without matching a token. 3579 * 3580 * @since 6.5.0 3581 * 3582 * @return string|null Name of the matched token. 3583 */ 3584 public function get_token_name(): ?string { 3585 switch ( $this->parser_state ) { 3586 case self::STATE_MATCHED_TAG: 3587 return $this->get_tag(); 3588 3589 case self::STATE_TEXT_NODE: 3590 return '#text'; 3591 3592 case self::STATE_CDATA_NODE: 3593 return '#cdata-section'; 3594 3595 case self::STATE_COMMENT: 3596 return '#comment'; 3597 3598 case self::STATE_DOCTYPE: 3599 return 'html'; 3600 3601 case self::STATE_PRESUMPTUOUS_TAG: 3602 return '#presumptuous-tag'; 3603 3604 case self::STATE_FUNKY_COMMENT: 3605 return '#funky-comment'; 3606 3607 case self::STATE_PROCESSING_INSTRUCTION: 3608 return '#processing-instruction'; 3609 } 3610 3611 return null; 3612 } 3613 3614 /** 3615 * Indicates what kind of comment produced the comment node. 3616 * 3617 * Because there are different kinds of HTML syntax which produce 3618 * comments, the Tag Processor tracks and exposes this as a type 3619 * for the comment. Nominally only regular HTML comments exist as 3620 * they are commonly known, but a number of unrelated syntax errors 3621 * also produce comments. 3622 * 3623 * @see self::COMMENT_AS_ABRUPTLY_CLOSED_COMMENT 3624 * @see self::COMMENT_AS_CDATA_LOOKALIKE 3625 * @see self::COMMENT_AS_INVALID_HTML 3626 * @see self::COMMENT_AS_HTML_COMMENT 3627 * @see self::COMMENT_AS_PI_NODE_LOOKALIKE 3628 * 3629 * @since 6.5.0 3630 * 3631 * @return string|null 3632 */ 3633 public function get_comment_type(): ?string { 3634 if ( self::STATE_COMMENT !== $this->parser_state ) { 3635 return null; 3636 } 3637 3638 return $this->comment_type; 3639 } 3640 3641 /** 3642 * Returns the text of a matched comment or null if not on a comment type node. 3643 * 3644 * This method returns the entire text content of a comment node as it 3645 * would appear in the browser. 3646 * 3647 * This differs from {@see ::get_modifiable_text()} in that certain comment 3648 * types in the HTML API cannot allow their entire comment text content to 3649 * be modified. Namely, "bogus comments" of the form `<?xml not allowed in html>` 3650 * will create a comment whose text content starts with `?`. Note that if 3651 * that character were modified, it would be possible to change the node 3652 * type. 3653 * 3654 * @since 6.7.0 3655 * 3656 * @return string|null The comment text as it would appear in the browser or null 3657 * if not on a comment type node. 3658 */ 3659 public function get_full_comment_text(): ?string { 3660 if ( self::STATE_FUNKY_COMMENT === $this->parser_state ) { 3661 return $this->get_modifiable_text(); 3662 } 3663 3664 if ( self::STATE_COMMENT !== $this->parser_state ) { 3665 return null; 3666 } 3667 3668 switch ( $this->get_comment_type() ) { 3669 case self::COMMENT_AS_HTML_COMMENT: 3670 case self::COMMENT_AS_ABRUPTLY_CLOSED_COMMENT: 3671 return $this->get_modifiable_text(); 3672 3673 case self::COMMENT_AS_CDATA_LOOKALIKE: 3674 return "[CDATA[{$this->get_modifiable_text()}]]"; 3675 3676 case self::COMMENT_AS_PI_NODE_LOOKALIKE: 3677 return "?{$this->get_tag()}{$this->get_modifiable_text()}?"; 3678 3679 /* 3680 * This represents "bogus comments state" from HTML tokenization. 3681 * This can be entered by `<?` or `<!`, where `?` is included in 3682 * the comment text but `!` is not. 3683 */ 3684 case self::COMMENT_AS_INVALID_HTML: 3685 $preceding_character = $this->html[ $this->text_starts_at - 1 ]; 3686 $comment_start = '?' === $preceding_character ? '?' : ''; 3687 return "{$comment_start}{$this->get_modifiable_text()}"; 3688 } 3689 3690 return null; 3691 } 3692 3693 /** 3694 * Subdivides a matched text node, splitting NULL byte sequences and decoded whitespace as 3695 * distinct nodes prefixes. 3696 * 3697 * Note that once anything that's neither a NULL byte nor decoded whitespace is 3698 * encountered, then the remainder of the text node is left intact as generic text. 3699 * 3700 * - The HTML Processor uses this to apply distinct rules for different kinds of text. 3701 * - Inter-element whitespace can be detected and skipped with this method. 3702 * 3703 * Text nodes aren't eagerly subdivided because there's no need to split them unless 3704 * decisions are being made on NULL byte sequences or whitespace-only text. 3705 * 3706 * Example: 3707 * 3708 * $processor = new WP_HTML_Tag_Processor( "\x00Apples & Oranges" ); 3709 * true === $processor->next_token(); // Text is "Apples & Oranges". 3710 * true === $processor->subdivide_text_appropriately(); // Text is "". 3711 * true === $processor->next_token(); // Text is "Apples & Oranges". 3712 * false === $processor->subdivide_text_appropriately(); 3713 * 3714 * $processor = new WP_HTML_Tag_Processor( "
 \r\n\tMore" ); 3715 * true === $processor->next_token(); // Text is "␍ ␊␉More". 3716 * true === $processor->subdivide_text_appropriately(); // Text is "␍ ␊␉". 3717 * true === $processor->next_token(); // Text is "More". 3718 * false === $processor->subdivide_text_appropriately(); 3719 * 3720 * @since 6.7.0 3721 * 3722 * @return bool Whether the text node was subdivided. 3723 */ 3724 public function subdivide_text_appropriately(): bool { 3725 if ( self::STATE_TEXT_NODE !== $this->parser_state ) { 3726 return false; 3727 } 3728 3729 $this->text_node_classification = self::TEXT_IS_GENERIC; 3730 3731 /* 3732 * NULL bytes are treated categorically different than numeric character 3733 * references whose number is zero. `�` is not the same as `"\x00"`. 3734 */ 3735 $leading_nulls = strspn( $this->html, "\x00", $this->text_starts_at, $this->text_length ); 3736 if ( $leading_nulls > 0 ) { 3737 $this->token_length = $leading_nulls; 3738 $this->text_length = $leading_nulls; 3739 $this->bytes_already_parsed = $this->token_starts_at + $leading_nulls; 3740 $this->text_node_classification = self::TEXT_IS_NULL_SEQUENCE; 3741 return true; 3742 } 3743 3744 /* 3745 * Start a decoding loop to determine the point at which the 3746 * text subdivides. This entails raw whitespace bytes and any 3747 * character reference that decodes to the same. 3748 */ 3749 $at = $this->text_starts_at; 3750 $end = $this->text_starts_at + $this->text_length; 3751 while ( $at < $end ) { 3752 $skipped = strspn( $this->html, " \t\f\r\n", $at, $end - $at ); 3753 $at += $skipped; 3754 3755 if ( $at < $end && '&' === $this->html[ $at ] ) { 3756 $matched_byte_length = null; 3757 $replacement = WP_HTML_Decoder::read_character_reference( 'data', $this->html, $at, $matched_byte_length ); 3758 if ( isset( $replacement ) && 1 === strspn( $replacement, " \t\f\r\n" ) ) { 3759 $at += $matched_byte_length; 3760 continue; 3761 } 3762 } 3763 3764 break; 3765 } 3766 3767 if ( $at > $this->text_starts_at ) { 3768 $new_length = $at - $this->text_starts_at; 3769 $this->text_length = $new_length; 3770 $this->token_length = $new_length; 3771 $this->bytes_already_parsed = $at; 3772 $this->text_node_classification = self::TEXT_IS_WHITESPACE; 3773 return true; 3774 } 3775 3776 return false; 3777 } 3778 3779 /** 3780 * Returns the modifiable text for a matched token, or an empty string. 3781 * 3782 * Modifiable text is text content that may be read and changed without 3783 * changing the HTML structure of the document around it. This includes 3784 * the contents of `#text` nodes in the HTML as well as the inner 3785 * contents of HTML comments, Processing Instructions, and others, even 3786 * though these nodes aren't part of a parsed DOM tree. They also contain 3787 * the contents of SCRIPT and STYLE tags, of TEXTAREA tags, and of any 3788 * other section in an HTML document which cannot contain HTML markup (DATA). 3789 * 3790 * If a token has no modifiable text then an empty string is returned to 3791 * avoid needless crashing or type errors. An empty string does not mean 3792 * that a token has modifiable text, and a token with modifiable text may 3793 * have an empty string (e.g. a comment with no contents). 3794 * 3795 * Limitations: 3796 * 3797 * - This function will not strip the leading newline appropriately 3798 * after seeking into a LISTING or PRE element. To ensure that the 3799 * newline is treated properly, seek to the LISTING or PRE opening 3800 * tag instead of to the first text node inside the element. 3801 * 3802 * @since 6.5.0 3803 * @since 6.7.0 Replaces NULL bytes (U+0000) and newlines appropriately. 3804 * 3805 * @return string 3806 */ 3807 public function get_modifiable_text(): string { 3808 $has_enqueued_update = isset( $this->lexical_updates['modifiable text'] ); 3809 3810 if ( ! $has_enqueued_update && ( null === $this->text_starts_at || 0 === $this->text_length ) ) { 3811 return ''; 3812 } 3813 3814 $text = $has_enqueued_update 3815 ? $this->lexical_updates['modifiable text']->text 3816 : substr( $this->html, $this->text_starts_at, $this->text_length ); 3817 3818 /* 3819 * An enqueued processing instruction update holds normalized raw 3820 * syntax spanning from the end of the target through the end of 3821 * the token: a separating space, the data, and the `?>` closer. 3822 * The data is found by skipping the leading whitespace and 3823 * dropping the two bytes of the closer. 3824 * 3825 * @see WP_HTML_Tag_Processor::set_modifiable_text() 3826 */ 3827 if ( $has_enqueued_update && self::STATE_PROCESSING_INSTRUCTION === $this->parser_state ) { 3828 $text = substr( $text, strspn( $text, " \t\f\r\n" ), -2 ); 3829 } 3830 3831 /* 3832 * Pre-processing the input stream would normally happen before 3833 * any parsing is done, but deferring it means it's possible to 3834 * skip in most cases. When getting the modifiable text, however 3835 * it's important to apply the pre-processing steps, which is 3836 * normalizing newlines. 3837 * 3838 * @see https://html.spec.whatwg.org/#preprocessing-the-input-stream 3839 * @see https://infra.spec.whatwg.org/#normalize-newlines 3840 */ 3841 $text = str_replace( "\r\n", "\n", $text ); 3842 $text = str_replace( "\r", "\n", $text ); 3843 3844 // Comment and processing instruction data is not decoded. 3845 if ( 3846 self::STATE_CDATA_NODE === $this->parser_state || 3847 self::STATE_COMMENT === $this->parser_state || 3848 self::STATE_DOCTYPE === $this->parser_state || 3849 self::STATE_FUNKY_COMMENT === $this->parser_state || 3850 self::STATE_PROCESSING_INSTRUCTION === $this->parser_state 3851 ) { 3852 return str_replace( "\x00", "\u{FFFD}", $text ); 3853 } 3854 3855 $tag_name = $this->get_token_name(); 3856 if ( 3857 // Script data is not decoded. 3858 'SCRIPT' === $tag_name || 3859 3860 // RAWTEXT data is not decoded. 3861 'IFRAME' === $tag_name || 3862 'NOEMBED' === $tag_name || 3863 'NOFRAMES' === $tag_name || 3864 'STYLE' === $tag_name || 3865 'XMP' === $tag_name 3866 ) { 3867 return str_replace( "\x00", "\u{FFFD}", $text ); 3868 } 3869 3870 $decoded = WP_HTML_Decoder::decode_text_node( $text ); 3871 3872 /* 3873 * Skip the first line feed after LISTING, PRE, and TEXTAREA opening tags. 3874 * 3875 * Note that this first newline may come in the form of a character 3876 * reference, such as `
`, and so it's important to perform 3877 * this transformation only after decoding the raw text content. 3878 */ 3879 if ( 3880 ( "\n" === ( $decoded[0] ?? '' ) ) && 3881 ( ( $this->skip_newline_at === $this->token_starts_at && '#text' === $tag_name ) || 'TEXTAREA' === $tag_name ) 3882 ) { 3883 $decoded = substr( $decoded, 1 ); 3884 } 3885 3886 /* 3887 * Only in normative text nodes does the NULL byte (U+0000) get removed. 3888 * In all other contexts it's replaced by the replacement character (U+FFFD) 3889 * for security reasons (to avoid joining together strings that were safe 3890 * when separated, but not when joined). 3891 * 3892 * @todo Inside HTML integration points and MathML integration points, the 3893 * text is processed according to the insertion mode, not according 3894 * to the foreign content rules. This should strip the NULL bytes. 3895 */ 3896 return ( '#text' === $tag_name && 'html' === $this->get_namespace() ) 3897 ? str_replace( "\x00", '', $decoded ) 3898 : str_replace( "\x00", "\u{FFFD}", $decoded ); 3899 } 3900 3901 /** 3902 * Sets the modifiable text for the matched token, if matched. 3903 * 3904 * Modifiable text is text content that may be read and changed without 3905 * changing the HTML structure of the document around it. This includes 3906 * the contents of `#text` nodes in the HTML as well as the inner 3907 * contents of HTML comments, Processing Instructions, and others, even 3908 * though these nodes aren't part of a parsed DOM tree. They also contain 3909 * the contents of SCRIPT and STYLE tags, of TEXTAREA tags, and of any 3910 * other section in an HTML document which cannot contain HTML markup (DATA). 3911 * 3912 * Not all modifiable text may be set by this method, and not all content 3913 * may be set as modifiable text. In the case that this fails it will return 3914 * `false` indicating as much. For instance, if the contents of a SCRIPT 3915 * element are neither JavaScript nor JSON, it’s not possible to guarantee 3916 * that escaping strings like `</script>` won’t break the script; in these 3917 * cases, updates will be rejected and it’s up to calling code to perform 3918 * language-specific escaping or workarounds. Similarly, it will not allow 3919 * setting content into a comment which would prematurely terminate the comment, 3920 * or processing instruction data which cannot be represented: data containing 3921 * a `>`, which would prematurely terminate the processing instruction, or data 3922 * with leading whitespace, which is indistinguishable from the whitespace 3923 * separating the data from its target. 3924 * 3925 * Example: 3926 * 3927 * // Add a preface to all STYLE contents. 3928 * while ( $processor->next_tag( 'STYLE' ) ) { 3929 * $style = $processor->get_modifiable_text(); 3930 * $processor->set_modifiable_text( "// Made with love on the World Wide Web\n{$style}" ); 3931 * } 3932 * 3933 * // Replace smiley text with Emoji smilies. 3934 * while ( $processor->next_token() ) { 3935 * if ( '#text' !== $processor->get_token_name() ) { 3936 * continue; 3937 * } 3938 * 3939 * $chunk = $processor->get_modifiable_text(); 3940 * if ( ! str_contains( $chunk, ':)' ) ) { 3941 * continue; 3942 * } 3943 * 3944 * $processor->set_modifiable_text( str_replace( ':)', '🙂', $chunk ) ); 3945 * } 3946 * 3947 * This function handles all necessary HTML encoding. Provide normal, unescaped string values. 3948 * The HTML API will encode the strings appropriately so that the browser will interpret them 3949 * as the intended value. 3950 * 3951 * Example: 3952 * 3953 * // Renders as “Eggs & Milk” in a browser, encoded as `<p>Eggs & Milk</p>`. 3954 * $processor->set_modifiable_text( 'Eggs & Milk' ); 3955 * 3956 * // Renders as “Eggs & Milk” in a browser, encoded as `<p>Eggs &amp; Milk</p>`. 3957 * $processor->set_modifiable_text( 'Eggs & Milk' ); 3958 * 3959 * @since 6.7.0 3960 * @since 6.9.0 Escapes all character references instead of trying to avoid double-escaping. 3961 * @since 7.1.0 Supports setting processing instruction data. 3962 * 3963 * @param string $plaintext_content New text content to represent in the matched token. 3964 * @return bool Whether the text was able to update. 3965 */ 3966 public function set_modifiable_text( string $plaintext_content ): bool { 3967 if ( self::STATE_TEXT_NODE === $this->parser_state ) { 3968 $this->lexical_updates['modifiable text'] = new WP_HTML_Text_Replacement( 3969 $this->text_starts_at, 3970 $this->text_length, 3971 strtr( 3972 $plaintext_content, 3973 array( 3974 '<' => '<', 3975 '>' => '>', 3976 '&' => '&', 3977 '"' => '"', 3978 "'" => ''', 3979 ) 3980 ) 3981 ); 3982 3983 return true; 3984 } 3985 3986 // Comment data is not encoded. 3987 if ( 3988 self::STATE_COMMENT === $this->parser_state && 3989 self::COMMENT_AS_HTML_COMMENT === $this->comment_type 3990 ) { 3991 // Check if the text could close the comment. 3992 if ( 1 === preg_match( '/--!?>/', $plaintext_content ) ) { 3993 _doing_it_wrong( 3994 __METHOD__, 3995 __( 'Comment text cannot contain a comment closer.' ), 3996 '7.1.0' 3997 ); 3998 return false; 3999 } 4000 4001 $this->lexical_updates['modifiable text'] = new WP_HTML_Text_Replacement( 4002 $this->text_starts_at, 4003 $this->text_length, 4004 $plaintext_content 4005 ); 4006 4007 return true; 4008 } 4009 4010 // Processing instruction data is not encoded. 4011 if ( self::STATE_PROCESSING_INSTRUCTION === $this->parser_state ) { 4012 /* 4013 * A processing instruction ends at the first `>` in its 4014 * raw syntax: data containing one cannot be represented. 4015 */ 4016 if ( str_contains( $plaintext_content, '>' ) ) { 4017 _doing_it_wrong( 4018 __METHOD__, 4019 __( 'Processing instruction data cannot contain ">".' ), 4020 '7.1.0' 4021 ); 4022 return false; 4023 } 4024 4025 /* 4026 * All whitespace between the target and the data is skipped when 4027 * parsing: data with leading whitespace cannot be represented. 4028 */ 4029 if ( 0 !== strspn( $plaintext_content, " \t\f\r\n" ) ) { 4030 _doing_it_wrong( 4031 __METHOD__, 4032 __( 'Processing instruction data cannot start with whitespace. Try ltrim( $plaintext_content, " \t\f\r\n" ).' ), 4033 '7.1.0' 4034 ); 4035 return false; 4036 } 4037 4038 /** 4039 * A single replacement spans from the end of the target through 4040 * the end of the token, normalizing the raw syntax for that 4041 * region into a fixed form: a separating space, the data, and 4042 * the `?>` closer. 4043 * 4044 * {@see self::get_modifiable_text()} performs necessary parsing to 4045 * return the correct processing instruction data based 4046 * on the modifiable text lexical update. 4047 */ 4048 $data_at = $this->tag_name_starts_at + $this->tag_name_length; 4049 4050 $this->lexical_updates['modifiable text'] = new WP_HTML_Text_Replacement( 4051 $data_at, 4052 $this->token_starts_at + $this->token_length - $data_at, 4053 " {$plaintext_content}?>" 4054 ); 4055 4056 return true; 4057 } 4058 4059 /* 4060 * The rest of this function handles modifiable text for special "atomic" HTML elements. 4061 * Only tags in the HTML namespace should be processed. 4062 */ 4063 if ( 4064 self::STATE_MATCHED_TAG !== $this->parser_state || 4065 'html' !== $this->get_namespace() 4066 ) { 4067 _doing_it_wrong( 4068 __METHOD__, 4069 __( 'This token does not support setting modifiable text.' ), 4070 '7.1.0' 4071 ); 4072 return false; 4073 } 4074 4075 switch ( $this->get_tag() ) { 4076 case 'SCRIPT': 4077 $script_content_type = $this->get_script_content_type(); 4078 4079 switch ( $script_content_type ) { 4080 case 'javascript': 4081 case 'json': 4082 $this->lexical_updates['modifiable text'] = new WP_HTML_Text_Replacement( 4083 $this->text_starts_at, 4084 $this->text_length, 4085 self::escape_javascript_script_contents( $plaintext_content ) 4086 ); 4087 return true; 4088 } 4089 4090 /* 4091 * If the script’s content type isn’t recognized and understandable then it’s 4092 * impossible to guarantee that escaping the content won’t cause runtime breakage. 4093 * For instance, if the script content type were PHP code then escaping with 4094 * `\u0073` would not be met by unescaping; rather, it could result in corrupted 4095 * data or even syntax errors. 4096 * 4097 * Because of this, content which could potentially modify the SCRIPT tag’s 4098 * HTML structure is rejected here. It’s the responsibility of calling code to 4099 * perform whatever semantic escaping is necessary to avoid problematic strings. 4100 */ 4101 if ( 4102 false !== stripos( $plaintext_content, '<script' ) || 4103 false !== stripos( $plaintext_content, '</script' ) 4104 ) { 4105 _doing_it_wrong( 4106 __METHOD__, 4107 __( 'SCRIPT text with an unrecognized content type cannot contain a SCRIPT tag. Apply the escaping appropriate for the content type.' ), 4108 '7.1.0' 4109 ); 4110 return false; 4111 } 4112 $this->lexical_updates['modifiable text'] = new WP_HTML_Text_Replacement( 4113 $this->text_starts_at, 4114 $this->text_length, 4115 $plaintext_content 4116 ); 4117 return true; 4118 4119 case 'IFRAME': 4120 case 'NOEMBED': 4121 case 'NOFRAMES': 4122 case 'XMP': 4123 $tag_name = $this->get_tag(); 4124 if ( false !== stripos( $plaintext_content, "</{$tag_name}" ) ) { 4125 _doing_it_wrong( 4126 __METHOD__, 4127 sprintf( 4128 /* translators: %s: HTML tag name. */ 4129 __( '%s text cannot contain its own closing tag.' ), 4130 $tag_name 4131 ), 4132 '7.1.0' 4133 ); 4134 return false; 4135 } 4136 4137 $this->lexical_updates['modifiable text'] = new WP_HTML_Text_Replacement( 4138 $this->text_starts_at, 4139 $this->text_length, 4140 $plaintext_content 4141 ); 4142 4143 return true; 4144 4145 case 'STYLE': 4146 $plaintext_content = preg_replace_callback( 4147 '~</(?P<TAG_NAME>style)~i', 4148 static function ( $tag_match ) { 4149 return "\\3c\\2f{$tag_match['TAG_NAME']}"; 4150 }, 4151 $plaintext_content 4152 ); 4153 4154 $this->lexical_updates['modifiable text'] = new WP_HTML_Text_Replacement( 4155 $this->text_starts_at, 4156 $this->text_length, 4157 $plaintext_content 4158 ); 4159 4160 return true; 4161 4162 case 'TEXTAREA': 4163 case 'TITLE': 4164 $plaintext_content = preg_replace_callback( 4165 "~</(?P<TAG_NAME>{$this->get_tag()})~i", 4166 static function ( $tag_match ) { 4167 return "</{$tag_match['TAG_NAME']}"; 4168 }, 4169 $plaintext_content 4170 ); 4171 4172 /* 4173 * HTML ignores a single leading newline in this context. If a leading newline 4174 * is intended, preserve it by adding an extra newline. 4175 */ 4176 if ( 4177 'TEXTAREA' === $this->get_tag() && 4178 1 === strspn( $plaintext_content, "\n\r", 0, 1 ) 4179 ) { 4180 $plaintext_content = "\n{$plaintext_content}"; 4181 } 4182 4183 /* 4184 * These don't _need_ to be escaped, but since they are decoded it's 4185 * safe to leave them escaped and this can prevent other code from 4186 * naively detecting tags within the contents. 4187 * 4188 * @todo It would be useful to prefix a multiline replacement text 4189 * with a newline, but not necessary. This is for aesthetics. 4190 */ 4191 $this->lexical_updates['modifiable text'] = new WP_HTML_Text_Replacement( 4192 $this->text_starts_at, 4193 $this->text_length, 4194 $plaintext_content 4195 ); 4196 4197 return true; 4198 } 4199 4200 _doing_it_wrong( 4201 __METHOD__, 4202 __( 'Only the IFRAME, NOEMBED, NOFRAMES, SCRIPT, STYLE, TEXTAREA, TITLE, and XMP tags support setting modifiable text.' ), 4203 '7.1.0' 4204 ); 4205 return false; 4206 } 4207 4208 /** 4209 * Returns the content type of the currently-matched HTML SCRIPT tag, if matched and 4210 * recognized, otherwise returns `null` to indicate an unrecognized content type. 4211 * 4212 * An HTML SCRIPT tag is a normal SCRIPT tag, but there can be SCRIPT elements inside 4213 * SVG and MathML elements as well, and these have different parsing rules than those 4214 * in general HTML. For this reason, no content-type inference is performed on those. 4215 * 4216 * Note! This concept is related but distinct from the MIME type of the script. 4217 * Parsing MUST match the specific algorithm in the HTML specification, which 4218 * relies on exact string comparison in some cases. MIME type decoding may be 4219 * performed on SVG or MathML SCRIPT tags. 4220 * 4221 * Only 'javascript' and 'json' content types are currently recognized. 4222 * 4223 * @see https://html.spec.whatwg.org/multipage/scripting.html#prepare-the-script-element 4224 * 4225 * @since 7.0.0 4226 * @ignore 4227 * 4228 * @return 'javascript'|'json'|null Type of script element content if matched and recognized. 4229 */ 4230 private function get_script_content_type(): ?string { 4231 // SVG and MathML SCRIPT elements are not recognized. 4232 if ( 'SCRIPT' !== $this->get_tag() || $this->get_namespace() !== 'html' ) { 4233 return null; 4234 } 4235 4236 /* 4237 * > If any of the following are true: 4238 * > - el has a type attribute whose value is the empty string; 4239 * > - el has no type attribute but it has a language attribute and that attribute's 4240 * > value is the empty string; or 4241 * > - el has neither a type attribute nor a language attribute, 4242 * > then let the script block's type string for this script element be "text/javascript". 4243 */ 4244 $type = $this->get_attribute( 'type' ); 4245 $lang = $this->get_attribute( 'language' ); 4246 4247 if ( true === $type || '' === $type ) { 4248 return 'javascript'; 4249 } 4250 4251 if ( null === $type && ( null === $lang || true === $lang || '' === $lang ) ) { 4252 return 'javascript'; 4253 } 4254 4255 /* 4256 * > Otherwise, if el has a type attribute, then let the script block's type string be 4257 * > the value of that attribute with leading and trailing ASCII whitespace stripped. 4258 * > Otherwise, el has a non-empty language attribute; let the script block's type string 4259 * > be the concatenation of "text/" and the value of el's language attribute. 4260 */ 4261 $type_string = is_string( $type ) ? trim( $type, " \t\f\r\n" ) : "text/{$lang}"; 4262 4263 // All matches are ASCII case-insensitive; eagerly lower-case for comparison. 4264 $type_string = strtolower( $type_string ); 4265 4266 /* 4267 * > If the script block's type string is a JavaScript MIME type essence match, then 4268 * > set el's type to "classic". 4269 * 4270 * > A string is a JavaScript MIME type essence match if it is an ASCII case-insensitive 4271 * > match for one of the JavaScript MIME type essence strings. 4272 * 4273 * > A JavaScript MIME type is any MIME type whose essence is one of the following: 4274 * > 4275 * > - application/ecmascript 4276 * > - application/javascript 4277 * > - application/x-ecmascript 4278 * > - application/x-javascript 4279 * > - text/ecmascript 4280 * > - text/javascript 4281 * > - text/javascript1.0 4282 * > - text/javascript1.1 4283 * > - text/javascript1.2 4284 * > - text/javascript1.3 4285 * > - text/javascript1.4 4286 * > - text/javascript1.5 4287 * > - text/jscript 4288 * > - text/livescript 4289 * > - text/x-ecmascript 4290 * > - text/x-javascript 4291 * 4292 * @see https://mimesniff.spec.whatwg.org/#javascript-mime-type-essence-match 4293 * @see https://mimesniff.spec.whatwg.org/#javascript-mime-type 4294 */ 4295 switch ( $type_string ) { 4296 case 'application/ecmascript': 4297 case 'application/javascript': 4298 case 'application/x-ecmascript': 4299 case 'application/x-javascript': 4300 case 'text/ecmascript': 4301 case 'text/javascript': 4302 case 'text/javascript1.0': 4303 case 'text/javascript1.1': 4304 case 'text/javascript1.2': 4305 case 'text/javascript1.3': 4306 case 'text/javascript1.4': 4307 case 'text/javascript1.5': 4308 case 'text/jscript': 4309 case 'text/livescript': 4310 case 'text/x-ecmascript': 4311 case 'text/x-javascript': 4312 return 'javascript'; 4313 4314 /* 4315 * > Otherwise, if the script block's type string is an ASCII case-insensitive match for 4316 * > the string "module", then set el's type to "module". 4317 * 4318 * A module is evaluated as JavaScript. 4319 */ 4320 case 'module': 4321 return 'javascript'; 4322 4323 /* 4324 * > Otherwise, if the script block's type string is an ASCII case-insensitive match for the string "importmap", then set el's type to "importmap". 4325 * > Otherwise, if the script block's type string is an ASCII case-insensitive match for the string "speculationrules", then set el's type to "speculationrules". 4326 * 4327 * These conditions indicate JSON content. 4328 */ 4329 case 'importmap': 4330 case 'speculationrules': 4331 return 'json'; 4332 4333 /** @todo Rely on a full MIME parser for determining JSON content. */ 4334 case 'application/json': 4335 case 'text/json': 4336 return 'json'; 4337 } 4338 4339 /* 4340 * > Otherwise, return. (No script is executed, and el's type is left as null.) 4341 */ 4342 return null; 4343 } 4344 4345 /** 4346 * Escape JavaScript and JSON script tag contents. 4347 * 4348 * Ensure that the script contents cannot modify the HTML structure or break out 4349 * of its containing SCRIPT element. JavaScript and JSON may both be escaped with 4350 * the same rules, even though there are additional escaping measures available 4351 * to JavaScript source code which aren’t applicable to serialized JSON data. 4352 * 4353 * A simple method safely escapes all content except for a few extremely rare and 4354 * unlikely exceptions: prevent the appearance of `<script` and `</script` within 4355 * the contents by replacing the first letter of the tag name with a Unicode escape. 4356 * 4357 * Example: 4358 * 4359 * $plaintext = '<script>document.write( "A </script> closes a script." );</script>'; 4360 * $escaped = '<script>document.write( "A </\u0073cript> closes a script." );</script>'; 4361 * 4362 * This works because of how parsing changes after encountering an opening SCRIPT 4363 * tag. The actual parsing comprises a complicated state machine, the result of 4364 * legacy behaviors and diverse browser support. However, without these two strings 4365 * in the script contents, two key things are ensured: `</script>` cannot appear to 4366 * prematurely close the tag, and the problematic double-escaped state becomes 4367 * unreachable. A JavaScript engine or JSON decoder will then decode the Unicode 4368 * escape (`\u0073`) back into its original plaintext value, but only after having 4369 * been safely extracted from the HTML. 4370 * 4371 * While it may seem tempting to replace the `<` character instead, doing so would 4372 * break JavaScript syntax. The `<` character is used in comparison operators and 4373 * other JavaScript syntax; replacing it would break valid JavaScript. Replacing 4374 * only the `s` in `<script` and `</script` avoids modifying JavaScript syntax. 4375 * 4376 * ### Exceptions 4377 * 4378 * This _should_ work everywhere, but there are some extreme exceptions. 4379 * 4380 * - Comments. 4381 * - Tagged templates, such as `String.raw()`, which provide access to “raw” strings. 4382 * - The `source` property of a RegExp object. 4383 * 4384 * Each of these exceptions appear at the source code level, not at the semantic or 4385 * evaluation level. Normal JavaScript will remain semantically equivalent after escaping, 4386 * but any JavaScript which analyzes the raw source code will see potentially-different 4387 * values. 4388 * 4389 * #### Comments 4390 * 4391 * Comments are never unescaped because they aren’t parsed by the JavaScript engine. 4392 * When viewing the source in a browser’s developer tools, the comments will retain 4393 * their escaped text. 4394 * 4395 * Example: 4396 * 4397 * // A comment: "</script>" 4398 * …becomes… 4399 * // A comment: "</\u0073cript>" 4400 * 4401 * #### Tagged templates. 4402 * 4403 * Tagged templates “enable the embedding of arbitrary string content, where escape 4404 * sequences may follow a different syntax.” For example, they can aid representing 4405 * a RegExp pattern or LaTex snippet within a JavaScript string, where the string 4406 * escape characters might get noisy and distracting. 4407 * 4408 * Example: 4409 * 4410 * console.log( 'A \notin B' ); // Prints a newline because of the "\n". 4411 * console.log( 'A \\notin B' ); // Prints "A \notin B". 4412 * console.log( String.raw`A \notin B` ); // Prints "A \notin B". 4413 * 4414 * This means that if `<script` transforms into `<\u0073cript` _inside_ a raw string 4415 * or tagged template literal which relies on its `.raw` property, the output of the 4416 * code will be different after escaping. 4417 * 4418 * Example: 4419 * 4420 * console.log( String.raw`</script>` ); // Prematurely closes the SCRIPT element. 4421 * console.log( String.raw`</\u0073cript>` ); // Prints "</\u0073cript". 4422 * 4423 * #### RegExp sources. 4424 * 4425 * The RegExp object exposes its raw source in a similar way to how tagged templates and raw 4426 * strings do. Thankfully, because escape sequences are decoded when compiling the pattern, 4427 * escaped RegExp patterns will match the same way as the plaintext sequences would. 4428 * 4429 * Example: 4430 * 4431 * true === /<script>/.test( '<script>' ); 4432 * true === /<\u0073cript>/.test( '<script>' ); 4433 * 4434 * However, as with raw strings, any code which reads the source will see the escaped value 4435 * instead of the decoded one. 4436 * 4437 * Example: 4438 * 4439 * console.log( /<script>/.source ); // Prints "<script>". 4440 * console.log( /<\u0073cript>/.source ); // Prints "<\u0073cript>". 4441 * 4442 * #### Unsupported escaping. 4443 * 4444 * It is not possible to properly represent every possible JavaScript source file 4445 * inside a SCRIPT element. As with CSS stylesheets, SVG images, and MathML, the 4446 * only 100% reliable way to represent all possible inputs is to link to external 4447 * files of the given content-type. 4448 * 4449 * In some cases it’s possible to manually prevent escaping issues. These are not 4450 * automatically handled by this function because doing so would require a full 4451 * JavaScript tokenizer. Consider the following example listing various ways to 4452 * manually escape a closing script tag. 4453 * 4454 * Example: 4455 * 4456 * console.log( String.raw`</script>` ); // !!UNSAFE!! Will be escaped. 4457 * console.log( String.raw`</\u0073cript>` ); // "</\u0073cript>" 4458 * console.log( String.raw`</scr` + String.raw`ipt>` ); // "</script>" 4459 * console.log( String.raw`</${"script"}>` ); // "</script>" 4460 * console.log( '</scr' + 'ipt>' ); // "</script>" 4461 * console.log( "\x3C/script>" ); // "</script>" 4462 * console.log( "<\/script>" ); // "</script>" 4463 * 4464 * The following graph is a simplified interpretation of how HTML interprets the contents 4465 * of a SCRIPT tag and identifies the closing tag. It is useful to understand what text 4466 * is dangerous inside of a SCRIPT tag and why different approaches to escaping work. 4467 * 4468 * Open script 4469 * │ 4470 * ▼ 4471 * ╔═════════════════════════════════════════╗ <!--(…)> 4472 * ║ ║ (all dashes) 4473 * ║ script ╟────────────────╮ 4474 * ║ data ║ │ 4475 * ╭───────────╢ ║ ◀──────────────╯ 4476 * │ ╚═╤═══════════════════════════════════════╝ 4477 * │ │ ▲ ▲ 4478 * │ │ <!-- │ --> ╰─────╮ 4479 * │ ▼ │ │ 4480 * │ ┌─────────────────┴───────────────────────┐ │ 4481 * │ </script¹ │ escaped │ │ 4482 * │ └─┬─────────────────────────────┬─────────┘ │ 4483 * │ │ ▲ │ │ --> 4484 * │ │ </script¹ │ </script¹ │ <script¹ │ 4485 * │ ▼ │ ▼ │ 4486 * │ ╔══════════════╗ │ ┌───────────┐ │ 4487 * │ ║ Close script ║ │ │ double │ │ 4488 * ╰──────────▶║ ║ ╰───────────┤ escaped ├──╯ 4489 * ╚══════════════╝ └───────────┘ 4490 * 4491 * ¹ = Case insensitive 'script' followed by one of ' \t\f\r\n/>', known 4492 * as “tag-name-terminating characters.” This sequence forms the start 4493 * of what could be a SCRIPT opening or closing tag. 4494 * 4495 * @see https://html.spec.whatwg.org/#restrictions-for-contents-of-script-elements 4496 * @see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Template_literals#specifications 4497 * @see wp_html_api_script_element_escaping_diagram_source() 4498 * 4499 * @since 7.0.0 4500 * @ignore 4501 * 4502 * @param string $sourcecode Raw contents intended to be serialized into an HTML SCRIPT element. 4503 * @return string Escaped form of input contents which will not lead to premature closing of the containing SCRIPT element. 4504 */ 4505 private static function escape_javascript_script_contents( string $sourcecode ): string { 4506 $at = 0; 4507 $was_at = 0; 4508 $end = strlen( $sourcecode ); 4509 $escaped = ''; 4510 4511 /* 4512 * Replace all instances of the ASCII case-insensitive match of "<script" 4513 * and "</script", when followed by whitespace or "/" or ">", by using a 4514 * character replacement for the "s" (or the "S"). 4515 */ 4516 while ( $at < $end ) { 4517 $tag_at = strpos( $sourcecode, '<', $at ); 4518 if ( false === $tag_at ) { 4519 break; 4520 } 4521 4522 $tag_name_at = $tag_at + 1; 4523 $has_closing_slash = $tag_name_at < $end && '/' === $sourcecode[ $tag_name_at ]; 4524 $tag_name_at += $has_closing_slash ? 1 : 0; 4525 4526 if ( 0 !== substr_compare( $sourcecode, 'script', $tag_name_at, 6, true ) ) { 4527 $at = $tag_at + 1; 4528 continue; 4529 } 4530 4531 if ( 1 !== strspn( $sourcecode, " \t\f\r\n/>", $tag_name_at + 6, 1 ) ) { 4532 $at = $tag_name_at + 6; 4533 continue; 4534 } 4535 4536 $escaped .= substr( $sourcecode, $was_at, $tag_name_at - $was_at ); 4537 $escaped .= 's' === $sourcecode[ $tag_name_at ] ? '\u0073' : '\u0053'; 4538 $was_at = $tag_name_at + 1; 4539 $at = $tag_name_at + 7; 4540 } 4541 4542 if ( '' === $escaped ) { 4543 return $sourcecode; 4544 } 4545 4546 if ( $was_at < $end ) { 4547 $escaped .= substr( $sourcecode, $was_at ); 4548 } 4549 4550 return $escaped; 4551 } 4552 4553 /** 4554 * Updates or creates a new attribute on the currently matched tag with the passed value. 4555 * 4556 * This function handles all necessary HTML encoding. Provide normal, unescaped string values. 4557 * The HTML API will encode the strings appropriately so that the browser will interpret them 4558 * as the intended value. 4559 * 4560 * Example: 4561 * 4562 * // Renders “Eggs & Milk” in a browser, encoded as `<abbr title="Eggs & Milk">`. 4563 * $processor->set_attribute( 'title', 'Eggs & Milk' ); 4564 * 4565 * // Renders “Eggs & Milk” in a browser, encoded as `<abbr title="Eggs &amp; Milk">`. 4566 * $processor->set_attribute( 'title', 'Eggs & Milk' ); 4567 * 4568 * // Renders `true` as `<abbr title>`. 4569 * $processor->set_attribute( 'title', true ); 4570 * 4571 * // Renders without the attribute for `false` as `<abbr>`. 4572 * $processor->set_attribute( 'title', false ); 4573 * 4574 * Special handling is provided for boolean attribute values: 4575 * - When `true` is passed as the value, then only the attribute name is added to the tag. 4576 * - When `false` is passed, the attribute gets removed if it existed before. 4577 * 4578 * @since 6.2.0 4579 * @since 6.2.1 Fix: Only create a single update for multiple calls with case-variant attribute names. 4580 * @since 6.9.0 Escapes all character references instead of trying to avoid double-escaping. 4581 * 4582 * @param string $name The attribute name to target. 4583 * @param string|bool $value The new attribute value. 4584 * @return bool Whether an attribute value was set. 4585 */ 4586 public function set_attribute( $name, $value ): bool { 4587 if ( 4588 self::STATE_MATCHED_TAG !== $this->parser_state || 4589 $this->is_closing_tag 4590 ) { 4591 return false; 4592 } 4593 4594 $name_length = strlen( $name ); 4595 4596 /** 4597 * WordPress rejects more characters than are strictly forbidden 4598 * in HTML5. This is to prevent additional security risks deeper 4599 * in the WordPress and plugin stack. Specifically the following 4600 * are not allowed to be set as part of an HTML attribute name: 4601 * 4602 * - greater-than “>” 4603 * - ampersand “&” 4604 * 4605 * @see https://html.spec.whatwg.org/#attributes-2 4606 */ 4607 if ( 4608 0 === $name_length || 4609 // Syntax-like characters. 4610 strcspn( $name, '"\'>&</ =' ) !== $name_length || 4611 // Control characters. 4612 strcspn( 4613 $name, 4614 "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0A\x0B\x0C\x0D\x0E\x0F" . 4615 "\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1A\x1B\x1C\x1D\x1E\x1F" 4616 ) !== $name_length || 4617 // Unicode noncharacters. 4618 wp_has_noncharacters( $name ) 4619 ) { 4620 _doing_it_wrong( 4621 __METHOD__, 4622 __( 'Invalid attribute name.' ), 4623 '6.2.0' 4624 ); 4625 4626 return false; 4627 } 4628 4629 /* 4630 * > The values "true" and "false" are not allowed on boolean attributes. 4631 * > To represent a false value, the attribute has to be omitted altogether. 4632 * - HTML5 spec, https://html.spec.whatwg.org/#boolean-attributes 4633 */ 4634 if ( false === $value ) { 4635 return $this->remove_attribute( $name ); 4636 } 4637 4638 if ( true === $value ) { 4639 $updated_attribute = $name; 4640 } else { 4641 $comparable_name = strtolower( $name ); 4642 4643 /** 4644 * Escape attribute values appropriately. 4645 * 4646 * @see https://html.spec.whatwg.org/#attributes-3 4647 */ 4648 $escaped_new_value = in_array( $comparable_name, wp_kses_uri_attributes(), true ) 4649 ? esc_url( $value ) 4650 : strtr( 4651 $value, 4652 array( 4653 '<' => '<', 4654 '>' => '>', 4655 '&' => '&', 4656 '"' => '"', 4657 "'" => ''', 4658 ) 4659 ); 4660 4661 // If the escaping functions wiped out the update, reject it and indicate it was rejected. 4662 if ( '' === $escaped_new_value && '' !== $value ) { 4663 return false; 4664 } 4665 4666 $updated_attribute = "{$name}=\"{$escaped_new_value}\""; 4667 } 4668 4669 /* 4670 * > There must never be two or more attributes on 4671 * > the same start tag whose names are an ASCII 4672 * > case-insensitive match for each other. 4673 * - HTML 5 spec 4674 * 4675 * @see https://html.spec.whatwg.org/multipage/syntax.html#attributes-2:ascii-case-insensitive 4676 */ 4677 $comparable_name = strtolower( $name ); 4678 4679 if ( isset( $this->attributes[ $comparable_name ] ) ) { 4680 /* 4681 * Update an existing attribute. 4682 * 4683 * Example – set attribute id to "new" in <div id="initial_id" />: 4684 * 4685 * <div id="initial_id"/> 4686 * ^-------------^ 4687 * start end 4688 * replacement: `id="new"` 4689 * 4690 * Result: <div id="new"/> 4691 */ 4692 $existing_attribute = $this->attributes[ $comparable_name ]; 4693 $this->lexical_updates[ $comparable_name ] = new WP_HTML_Text_Replacement( 4694 $existing_attribute->start, 4695 $existing_attribute->length, 4696 $updated_attribute 4697 ); 4698 } else { 4699 /* 4700 * Create a new attribute at the tag's name end. 4701 * 4702 * Example – add attribute id="new" to <div />: 4703 * 4704 * <div/> 4705 * ^ 4706 * start and end 4707 * replacement: ` id="new"` 4708 * 4709 * Result: <div id="new"/> 4710 */ 4711 $this->lexical_updates[ $comparable_name ] = new WP_HTML_Text_Replacement( 4712 $this->tag_name_starts_at + $this->tag_name_length, 4713 0, 4714 ' ' . $updated_attribute 4715 ); 4716 } 4717 4718 /* 4719 * Any calls to update the `class` attribute directly should wipe out any 4720 * enqueued class changes from `add_class` and `remove_class`. 4721 */ 4722 if ( 'class' === $comparable_name && ! empty( $this->classname_updates ) ) { 4723 $this->classname_updates = array(); 4724 } 4725 4726 return true; 4727 } 4728 4729 /** 4730 * Remove an attribute from the currently-matched tag. 4731 * 4732 * @since 6.2.0 4733 * 4734 * @param string $name The attribute name to remove. 4735 * @return bool Whether an attribute was removed. 4736 */ 4737 public function remove_attribute( $name ): bool { 4738 if ( 4739 self::STATE_MATCHED_TAG !== $this->parser_state || 4740 $this->is_closing_tag 4741 ) { 4742 return false; 4743 } 4744 4745 /* 4746 * > There must never be two or more attributes on 4747 * > the same start tag whose names are an ASCII 4748 * > case-insensitive match for each other. 4749 * - HTML 5 spec 4750 * 4751 * @see https://html.spec.whatwg.org/multipage/syntax.html#attributes-2:ascii-case-insensitive 4752 */ 4753 $name = strtolower( $name ); 4754 4755 /* 4756 * Any calls to update the `class` attribute directly should wipe out any 4757 * enqueued class changes from `add_class` and `remove_class`. 4758 */ 4759 if ( 'class' === $name && count( $this->classname_updates ) !== 0 ) { 4760 $this->classname_updates = array(); 4761 } 4762 4763 /* 4764 * If updating an attribute that didn't exist in the input 4765 * document, then remove the enqueued update and move on. 4766 * 4767 * For example, this might occur when calling `remove_attribute()` 4768 * after calling `set_attribute()` for the same attribute 4769 * and when that attribute wasn't originally present. 4770 */ 4771 if ( ! isset( $this->attributes[ $name ] ) ) { 4772 if ( isset( $this->lexical_updates[ $name ] ) ) { 4773 unset( $this->lexical_updates[ $name ] ); 4774 } 4775 return false; 4776 } 4777 4778 /* 4779 * Removes an existing tag attribute. 4780 * 4781 * Example – remove the attribute id from <div id="main"/>: 4782 * <div id="initial_id"/> 4783 * ^-------------^ 4784 * start end 4785 * replacement: `` 4786 * 4787 * Result: <div /> 4788 */ 4789 $this->lexical_updates[ $name ] = new WP_HTML_Text_Replacement( 4790 $this->attributes[ $name ]->start, 4791 $this->attributes[ $name ]->length, 4792 '' 4793 ); 4794 4795 // Removes any duplicated attributes if they were also present. 4796 foreach ( $this->duplicate_attributes[ $name ] ?? array() as $attribute_token ) { 4797 $this->lexical_updates[] = new WP_HTML_Text_Replacement( 4798 $attribute_token->start, 4799 $attribute_token->length, 4800 '' 4801 ); 4802 } 4803 4804 return true; 4805 } 4806 4807 /** 4808 * Adds a new class name to the currently matched tag. 4809 * 4810 * @since 6.2.0 4811 * 4812 * @param string $class_name The class name to add. 4813 * @return bool Whether the class was set to be added. 4814 */ 4815 public function add_class( $class_name ): bool { 4816 if ( 4817 self::STATE_MATCHED_TAG !== $this->parser_state || 4818 $this->is_closing_tag 4819 ) { 4820 return false; 4821 } 4822 4823 if ( self::QUIRKS_MODE !== $this->compat_mode ) { 4824 $this->classname_updates[ $class_name ] = self::ADD_CLASS; 4825 return true; 4826 } 4827 4828 /* 4829 * Because class names are matched ASCII-case-insensitively in quirks mode, 4830 * this needs to see if a case variant of the given class name is already 4831 * enqueued and update that existing entry, if so. This picks the casing of 4832 * the first-provided class name for all lexical variations. 4833 */ 4834 $class_name_length = strlen( $class_name ); 4835 foreach ( $this->classname_updates as $updated_name => $action ) { 4836 if ( 4837 strlen( $updated_name ) === $class_name_length && 4838 0 === substr_compare( $updated_name, $class_name, 0, $class_name_length, true ) 4839 ) { 4840 $this->classname_updates[ $updated_name ] = self::ADD_CLASS; 4841 return true; 4842 } 4843 } 4844 4845 $this->classname_updates[ $class_name ] = self::ADD_CLASS; 4846 return true; 4847 } 4848 4849 /** 4850 * Removes a class name from the currently matched tag. 4851 * 4852 * @since 6.2.0 4853 * 4854 * @param string $class_name The class name to remove. 4855 * @return bool Whether the class was set to be removed. 4856 */ 4857 public function remove_class( $class_name ): bool { 4858 if ( 4859 self::STATE_MATCHED_TAG !== $this->parser_state || 4860 $this->is_closing_tag 4861 ) { 4862 return false; 4863 } 4864 4865 if ( self::QUIRKS_MODE !== $this->compat_mode ) { 4866 $this->classname_updates[ $class_name ] = self::REMOVE_CLASS; 4867 return true; 4868 } 4869 4870 /* 4871 * Because class names are matched ASCII-case-insensitively in quirks mode, 4872 * this needs to see if a case variant of the given class name is already 4873 * enqueued and update that existing entry, if so. This picks the casing of 4874 * the first-provided class name for all lexical variations. 4875 */ 4876 $class_name_length = strlen( $class_name ); 4877 foreach ( $this->classname_updates as $updated_name => $action ) { 4878 if ( 4879 strlen( $updated_name ) === $class_name_length && 4880 0 === substr_compare( $updated_name, $class_name, 0, $class_name_length, true ) 4881 ) { 4882 $this->classname_updates[ $updated_name ] = self::REMOVE_CLASS; 4883 return true; 4884 } 4885 } 4886 4887 $this->classname_updates[ $class_name ] = self::REMOVE_CLASS; 4888 return true; 4889 } 4890 4891 /** 4892 * Returns the string representation of the HTML Tag Processor. 4893 * 4894 * @since 6.2.0 4895 * 4896 * @see WP_HTML_Tag_Processor::get_updated_html() 4897 * 4898 * @return string The processed HTML. 4899 */ 4900 public function __toString(): string { 4901 return $this->get_updated_html(); 4902 } 4903 4904 /** 4905 * Returns the string representation of the HTML Tag Processor. 4906 * 4907 * @since 6.2.0 4908 * @since 6.2.1 Shifts the internal cursor corresponding to the applied updates. 4909 * @since 6.4.0 No longer calls subclass method `next_tag()` after updating HTML. 4910 * 4911 * @return string The processed HTML. 4912 */ 4913 public function get_updated_html(): string { 4914 $requires_no_updating = 0 === count( $this->classname_updates ) && 0 === count( $this->lexical_updates ); 4915 4916 /* 4917 * When there is nothing more to update and nothing has already been 4918 * updated, return the original document and avoid a string copy. 4919 */ 4920 if ( $requires_no_updating ) { 4921 return $this->html; 4922 } 4923 4924 /* 4925 * Keep track of the position right before the current tag. This will 4926 * be necessary for reparsing the current tag after updating the HTML. 4927 */ 4928 $before_current_tag = $this->token_starts_at ?? 0; 4929 4930 /* 4931 * 1. Apply the enqueued edits and update all the pointers to reflect those changes. 4932 */ 4933 $this->class_name_updates_to_attributes_updates(); 4934 $before_current_tag += $this->apply_attributes_updates( $before_current_tag ); 4935 4936 /* 4937 * 2. Rewind to before the current tag and reparse to get updated attributes. 4938 * 4939 * At this point the internal cursor points to the end of the tag name. 4940 * Rewind before the tag name starts so that it's as if the cursor didn't 4941 * move; a call to `next_tag()` will reparse the recently-updated attributes 4942 * and additional calls to modify the attributes will apply at this same 4943 * location, but in order to avoid issues with subclasses that might add 4944 * behaviors to `next_tag()`, the internal methods should be called here 4945 * instead. 4946 * 4947 * It's important to note that in this specific place there will be no change 4948 * because the processor was already at a tag when this was called and it's 4949 * rewinding only to the beginning of this very tag before reprocessing it 4950 * and its attributes. 4951 * 4952 * <p>Previous HTML<em>More HTML</em></p> 4953 * ↑ │ back up by the length of the tag name plus the opening < 4954 * └←─┘ back up by strlen("em") + 1 ==> 3 4955 */ 4956 $this->bytes_already_parsed = $before_current_tag; 4957 $this->base_class_next_token(); 4958 4959 return $this->html; 4960 } 4961 4962 /** 4963 * Parses tag query input into internal search criteria. 4964 * 4965 * @since 6.2.0 4966 * @ignore 4967 * 4968 * @param array|string|null $query { 4969 * Optional. Which tag name to find, having which class, etc. Default is to find any tag. 4970 * 4971 * @type string|null $tag_name Which tag to find, or `null` for "any tag." 4972 * @type int|null $match_offset Find the Nth tag matching all search criteria. 4973 * 1 for "first" tag, 3 for "third," etc. 4974 * Defaults to first tag. 4975 * @type string|null $class_name Tag must contain this class name to match. 4976 * @type string $tag_closers "visit" or "skip": whether to stop on tag closers, e.g. </div>. 4977 * } 4978 */ 4979 private function parse_query( $query ) { 4980 if ( null !== $query && $query === $this->last_query ) { 4981 return; 4982 } 4983 4984 $this->last_query = $query; 4985 $this->sought_tag_name = null; 4986 $this->sought_class_name = null; 4987 $this->sought_match_offset = 1; 4988 $this->stop_on_tag_closers = false; 4989 4990 // A single string value means "find the tag of this name". 4991 if ( is_string( $query ) ) { 4992 $this->sought_tag_name = $query; 4993 return; 4994 } 4995 4996 // An empty query parameter applies no restrictions on the search. 4997 if ( null === $query ) { 4998 return; 4999 } 5000 5001 // If not using the string interface, an associative array is required. 5002 if ( ! is_array( $query ) ) { 5003 _doing_it_wrong( 5004 __METHOD__, 5005 __( 'The query argument must be an array or a tag name.' ), 5006 '6.2.0' 5007 ); 5008 return; 5009 } 5010 5011 if ( isset( $query['tag_name'] ) && is_string( $query['tag_name'] ) ) { 5012 $this->sought_tag_name = $query['tag_name']; 5013 } 5014 5015 if ( isset( $query['class_name'] ) && is_string( $query['class_name'] ) ) { 5016 $this->sought_class_name = $query['class_name']; 5017 } 5018 5019 if ( isset( $query['match_offset'] ) && is_int( $query['match_offset'] ) && 0 < $query['match_offset'] ) { 5020 $this->sought_match_offset = $query['match_offset']; 5021 } 5022 5023 if ( isset( $query['tag_closers'] ) ) { 5024 $this->stop_on_tag_closers = 'visit' === $query['tag_closers']; 5025 } 5026 } 5027 5028 5029 /** 5030 * Checks whether a given tag and its attributes match the search criteria. 5031 * 5032 * @since 6.2.0 5033 * @ignore 5034 * 5035 * @return bool Whether the given tag and its attribute match the search criteria. 5036 */ 5037 private function matches(): bool { 5038 if ( $this->is_closing_tag && ! $this->stop_on_tag_closers ) { 5039 return false; 5040 } 5041 5042 // Does the tag name match the requested tag name in a case-insensitive manner? 5043 if ( isset( $this->sought_tag_name ) ) { 5044 $tag_name = $this->get_tag(); 5045 if ( 5046 strlen( $this->sought_tag_name ) !== strlen( $tag_name ) || 5047 0 !== substr_compare( $tag_name, $this->sought_tag_name, 0, null, true ) 5048 ) { 5049 return false; 5050 } 5051 } 5052 5053 if ( null !== $this->sought_class_name && ! $this->has_class( $this->sought_class_name ) ) { 5054 return false; 5055 } 5056 5057 return true; 5058 } 5059 5060 /** 5061 * Gets DOCTYPE declaration info from a DOCTYPE token. 5062 * 5063 * DOCTYPE tokens may appear in many places in an HTML document. In most places, they are 5064 * simply ignored. The main parsing functions find the basic shape of DOCTYPE tokens but 5065 * do not perform detailed parsing. 5066 * 5067 * This method can be called to perform a full parse of the DOCTYPE token and retrieve 5068 * its information. 5069 * 5070 * @return WP_HTML_Doctype_Info|null The DOCTYPE declaration information or `null` if not 5071 * currently at a DOCTYPE node. 5072 */ 5073 public function get_doctype_info(): ?WP_HTML_Doctype_Info { 5074 if ( self::STATE_DOCTYPE !== $this->parser_state ) { 5075 return null; 5076 } 5077 5078 return WP_HTML_Doctype_Info::from_doctype_token( substr( $this->html, $this->token_starts_at, $this->token_length ) ); 5079 } 5080 5081 /** 5082 * Parser Ready State. 5083 * 5084 * Indicates that the parser is ready to run and waiting for a state transition. 5085 * It may not have started yet, or it may have just finished parsing a token and 5086 * is ready to find the next one. 5087 * 5088 * @since 6.5.0 5089 * 5090 * @access private 5091 */ 5092 const STATE_READY = 'STATE_READY'; 5093 5094 /** 5095 * Parser Complete State. 5096 * 5097 * Indicates that the parser has reached the end of the document and there is 5098 * nothing left to scan. It finished parsing the last token completely. 5099 * 5100 * @since 6.5.0 5101 * 5102 * @access private 5103 */ 5104 const STATE_COMPLETE = 'STATE_COMPLETE'; 5105 5106 /** 5107 * Parser Incomplete Input State. 5108 * 5109 * Indicates that the parser has reached the end of the document before finishing 5110 * a token. It started parsing a token but there is a possibility that the input 5111 * HTML document was truncated in the middle of a token. 5112 * 5113 * The parser is reset at the start of the incomplete token and has paused. There 5114 * is nothing more than can be scanned unless provided a more complete document. 5115 * 5116 * @since 6.5.0 5117 * 5118 * @access private 5119 */ 5120 const STATE_INCOMPLETE_INPUT = 'STATE_INCOMPLETE_INPUT'; 5121 5122 /** 5123 * Parser Matched Tag State. 5124 * 5125 * Indicates that the parser has found an HTML tag and it's possible to get 5126 * the tag name and read or modify its attributes (if it's not a closing tag). 5127 * 5128 * @since 6.5.0 5129 * 5130 * @access private 5131 */ 5132 const STATE_MATCHED_TAG = 'STATE_MATCHED_TAG'; 5133 5134 /** 5135 * Parser Text Node State. 5136 * 5137 * Indicates that the parser has found a text node and it's possible 5138 * to read and modify that text. 5139 * 5140 * @since 6.5.0 5141 * 5142 * @access private 5143 */ 5144 const STATE_TEXT_NODE = 'STATE_TEXT_NODE'; 5145 5146 /** 5147 * Parser CDATA Node State. 5148 * 5149 * Indicates that the parser has found a CDATA node and it's possible 5150 * to read and modify its modifiable text. Note that in HTML there are 5151 * no CDATA nodes outside of foreign content (SVG and MathML). Outside 5152 * of foreign content, they are treated as HTML comments. 5153 * 5154 * @since 6.5.0 5155 * 5156 * @access private 5157 */ 5158 const STATE_CDATA_NODE = 'STATE_CDATA_NODE'; 5159 5160 /** 5161 * Indicates that the parser has found an HTML comment and it's 5162 * possible to read and modify its modifiable text. 5163 * 5164 * @since 6.5.0 5165 * 5166 * @access private 5167 */ 5168 const STATE_COMMENT = 'STATE_COMMENT'; 5169 5170 /** 5171 * Indicates that the parser has found a DOCTYPE node and it's 5172 * possible to read its DOCTYPE information via `get_doctype_info()`. 5173 * 5174 * @since 6.5.0 5175 * 5176 * @access private 5177 */ 5178 const STATE_DOCTYPE = 'STATE_DOCTYPE'; 5179 5180 /** 5181 * Indicates that the parser has found an empty tag closer `</>`. 5182 * 5183 * Note that in HTML there are no empty tag closers, and they 5184 * are ignored. Nonetheless, the Tag Processor still 5185 * recognizes them as they appear in the HTML stream. 5186 * 5187 * These were historically discussed as a "presumptuous tag 5188 * closer," which would close the nearest open tag, but were 5189 * dismissed in favor of explicitly-closing tags. 5190 * 5191 * @since 6.5.0 5192 * 5193 * @access private 5194 */ 5195 const STATE_PRESUMPTUOUS_TAG = 'STATE_PRESUMPTUOUS_TAG'; 5196 5197 /** 5198 * Indicates that the parser has found a "funky comment" 5199 * and it's possible to read and modify its modifiable text. 5200 * 5201 * Example: 5202 * 5203 * </%url> 5204 * </{"wp-bit":"query/post-author"}> 5205 * </2> 5206 * 5207 * Funky comments are tag closers with invalid tag names. Note 5208 * that in HTML these are turned into bogus comments. Nonetheless, 5209 * the Tag Processor recognizes them in a stream of HTML and 5210 * exposes them for inspection and modification. 5211 * 5212 * @since 6.5.0 5213 * 5214 * @access private 5215 */ 5216 const STATE_FUNKY_COMMENT = 'STATE_WP_FUNKY'; 5217 5218 /** 5219 * Indicates that the parser has found a processing instruction 5220 * and it's possible to read its target and data. 5221 * 5222 * Example: 5223 * 5224 * <?wp-bit {"just": "kidding"}> 5225 * 5226 * Processing instructions with an allowable target are parsed 5227 * into processing instruction nodes. The reserved `xml` and 5228 * `xml-stylesheet` targets, and targets with characters outside 5229 * an ASCII-representable subset, are turned into bogus comments. 5230 * 5231 * @link https://html.spec.whatwg.org/multipage/parsing.html#processing-instruction-open-state 5232 * 5233 * @since 7.1.0 5234 * 5235 * @access private 5236 */ 5237 const STATE_PROCESSING_INSTRUCTION = 'STATE_PROCESSING_INSTRUCTION'; 5238 5239 /** 5240 * Indicates that a comment was created when encountering abruptly-closed HTML comment. 5241 * 5242 * Example: 5243 * 5244 * <!--> 5245 * <!---> 5246 * 5247 * @since 6.5.0 5248 */ 5249 const COMMENT_AS_ABRUPTLY_CLOSED_COMMENT = 'COMMENT_AS_ABRUPTLY_CLOSED_COMMENT'; 5250 5251 /** 5252 * Indicates that a comment would be parsed as a CDATA node, 5253 * were HTML to allow CDATA nodes outside of foreign content. 5254 * 5255 * Example: 5256 * 5257 * <![CDATA[This is a CDATA node.]]> 5258 * 5259 * This is an HTML comment, but it looks like a CDATA node. 5260 * 5261 * @since 6.5.0 5262 */ 5263 const COMMENT_AS_CDATA_LOOKALIKE = 'COMMENT_AS_CDATA_LOOKALIKE'; 5264 5265 /** 5266 * Indicates that a comment was created when encountering 5267 * normative HTML comment syntax. 5268 * 5269 * Example: 5270 * 5271 * <!-- this is a comment --> 5272 * 5273 * @since 6.5.0 5274 */ 5275 const COMMENT_AS_HTML_COMMENT = 'COMMENT_AS_HTML_COMMENT'; 5276 5277 /** 5278 * Indicates that a comment would be parsed as a Processing 5279 * Instruction node, were its target allowed within HTML. 5280 * 5281 * Example: 5282 * 5283 * <?xml version="1.0" ?> 5284 * <?wp.like count=5 ?> 5285 * 5286 * These are HTML comments, but they look like processing 5287 * instructions. HTML parses processing instructions with 5288 * an allowable target into processing instruction nodes, 5289 * but the reserved `xml` and `xml-stylesheet` targets and 5290 * XML-valid targets with characters outside of the allowed 5291 * set become bogus comments instead. 5292 * 5293 * @since 6.5.0 5294 * @since 7.1.0 Only applies to reserved and XML-specific target names; 5295 * other processing instructions produce their own token. 5296 */ 5297 const COMMENT_AS_PI_NODE_LOOKALIKE = 'COMMENT_AS_PI_NODE_LOOKALIKE'; 5298 5299 /** 5300 * Indicates that a comment was created when encountering invalid 5301 * HTML input, a so-called "bogus comment." 5302 * 5303 * Example: 5304 * 5305 * <?= nothing special ?> 5306 * <!{nothing special}> 5307 * 5308 * @since 6.5.0 5309 */ 5310 const COMMENT_AS_INVALID_HTML = 'COMMENT_AS_INVALID_HTML'; 5311 5312 /** 5313 * No-quirks mode document compatibility mode. 5314 * 5315 * > In no-quirks mode, the behavior is (hopefully) the desired behavior 5316 * > described by the modern HTML and CSS specifications. 5317 * 5318 * @see self::$compat_mode 5319 * @see https://developer.mozilla.org/en-US/docs/Web/HTML/Quirks_Mode_and_Standards_Mode 5320 * 5321 * @since 6.7.0 5322 * 5323 * @var string 5324 */ 5325 const NO_QUIRKS_MODE = 'no-quirks-mode'; 5326 5327 /** 5328 * Quirks mode document compatibility mode. 5329 * 5330 * > In quirks mode, layout emulates behavior in Navigator 4 and Internet 5331 * > Explorer 5. This is essential in order to support websites that were 5332 * > built before the widespread adoption of web standards. 5333 * 5334 * @see self::$compat_mode 5335 * @see https://developer.mozilla.org/en-US/docs/Web/HTML/Quirks_Mode_and_Standards_Mode 5336 * 5337 * @since 6.7.0 5338 * 5339 * @var string 5340 */ 5341 const QUIRKS_MODE = 'quirks-mode'; 5342 5343 /** 5344 * Indicates that a span of text may contain any combination of significant 5345 * kinds of characters: NULL bytes, whitespace, and others. 5346 * 5347 * @see self::$text_node_classification 5348 * @see self::subdivide_text_appropriately 5349 * 5350 * @since 6.7.0 5351 */ 5352 const TEXT_IS_GENERIC = 'TEXT_IS_GENERIC'; 5353 5354 /** 5355 * Indicates that a span of text comprises a sequence only of NULL bytes. 5356 * 5357 * @see self::$text_node_classification 5358 * @see self::subdivide_text_appropriately 5359 * 5360 * @since 6.7.0 5361 */ 5362 const TEXT_IS_NULL_SEQUENCE = 'TEXT_IS_NULL_SEQUENCE'; 5363 5364 /** 5365 * Indicates that a span of decoded text comprises only whitespace. 5366 * 5367 * @see self::$text_node_classification 5368 * @see self::subdivide_text_appropriately 5369 * 5370 * @since 6.7.0 5371 */ 5372 const TEXT_IS_WHITESPACE = 'TEXT_IS_WHITESPACE'; 5373 5374 /** 5375 * Wakeup magic method. 5376 * 5377 * @since 6.9.2 5378 */ 5379 public function __wakeup() { 5380 throw new \LogicException( __CLASS__ . ' should never be unserialized' ); 5381 } 5382 }
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