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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 * @since 6.2.0 693 * @var bool 694 */ 695 private $is_closing_tag; 696 697 /** 698 * Lazily-built index of attributes found within an HTML tag, keyed by the attribute name. 699 * 700 * Example: 701 * 702 * // Supposing the parser is working through this content 703 * // and stops after recognizing the `id` attribute. 704 * // <div id="test-4" class=outline title="data:text/plain;base64=asdk3nk1j3fo8"> 705 * // ^ parsing will continue from this point. 706 * $this->attributes = array( 707 * 'id' => new WP_HTML_Attribute_Token( 'id', 9, 6, 5, 11, false ) 708 * ); 709 * 710 * // When picking up parsing again, or when asking to find the 711 * // `class` attribute we will continue and add to this array. 712 * $this->attributes = array( 713 * 'id' => new WP_HTML_Attribute_Token( 'id', 9, 6, 5, 11, false ), 714 * 'class' => new WP_HTML_Attribute_Token( 'class', 23, 7, 17, 13, false ) 715 * ); 716 * 717 * // Note that only the `class` attribute value is stored in the index. 718 * // That's because it is the only value used by this class at the moment. 719 * 720 * @since 6.2.0 721 * @var WP_HTML_Attribute_Token[] 722 * @phpstan-var array<non-empty-string, WP_HTML_Attribute_Token> 723 */ 724 private $attributes = array(); 725 726 /** 727 * Tracks spans of duplicate attributes on a given tag, used for removing 728 * all copies of an attribute when calling `remove_attribute()`. 729 * 730 * @since 6.3.2 731 * 732 * @var (WP_HTML_Span[])[]|null 733 */ 734 private $duplicate_attributes = null; 735 736 /** 737 * Which class names to add or remove from a tag. 738 * 739 * These are tracked separately from attribute updates because they are 740 * semantically distinct, whereas this interface exists for the common 741 * case of adding and removing class names while other attributes are 742 * generally modified as with DOM `setAttribute` calls. 743 * 744 * When modifying an HTML document these will eventually be collapsed 745 * into a single `set_attribute( 'class', $changes )` call. 746 * 747 * Example: 748 * 749 * // Add the `wp-block-group` class, remove the `wp-group` class. 750 * $classname_updates = array( 751 * // Indexed by a comparable class name. 752 * 'wp-block-group' => WP_HTML_Tag_Processor::ADD_CLASS, 753 * 'wp-group' => WP_HTML_Tag_Processor::REMOVE_CLASS 754 * ); 755 * 756 * @since 6.2.0 757 * @var array<non-empty-string, self::ADD_CLASS|self::REMOVE_CLASS> 758 */ 759 private $classname_updates = array(); 760 761 /** 762 * Tracks a semantic location in the original HTML which 763 * shifts with updates as they are applied to the document. 764 * 765 * @since 6.2.0 766 * @var WP_HTML_Span[] 767 */ 768 protected $bookmarks = array(); 769 770 const ADD_CLASS = true; 771 const REMOVE_CLASS = false; 772 const SKIP_CLASS = null; 773 774 /** 775 * Lexical replacements to apply to input HTML document. 776 * 777 * "Lexical" in this class refers to the part of this class which 778 * operates on pure text _as text_ and not as HTML. There's a line 779 * between the public interface, with HTML-semantic methods like 780 * `set_attribute` and `add_class`, and an internal state that tracks 781 * text offsets in the input document. 782 * 783 * When higher-level HTML methods are called, those have to transform their 784 * operations (such as setting an attribute's value) into text diffing 785 * operations (such as replacing the sub-string from indices A to B with 786 * some given new string). These text-diffing operations are the lexical 787 * updates. 788 * 789 * As new higher-level methods are added they need to collapse their 790 * operations into these lower-level lexical updates since that's the 791 * Tag Processor's internal language of change. Any code which creates 792 * these lexical updates must ensure that they do not cross HTML syntax 793 * boundaries, however, so these should never be exposed outside of this 794 * class or any classes which intentionally expand its functionality. 795 * 796 * These are enqueued while editing the document instead of being immediately 797 * applied to avoid processing overhead, string allocations, and string 798 * copies when applying many updates to a single document. 799 * 800 * Example: 801 * 802 * // Replace an attribute stored with a new value, indices 803 * // sourced from the lazily-parsed HTML recognizer. 804 * $start = $attributes['src']->start; 805 * $length = $attributes['src']->length; 806 * $modifications[] = new WP_HTML_Text_Replacement( $start, $length, $new_value ); 807 * 808 * // Correspondingly, something like this will appear in this array. 809 * $lexical_updates = array( 810 * WP_HTML_Text_Replacement( 14, 28, 'https://my-site.my-domain/wp-content/uploads/2014/08/kittens.jpg' ) 811 * ); 812 * 813 * @since 6.2.0 814 * @var array<int|string, WP_HTML_Text_Replacement> 815 */ 816 protected $lexical_updates = array(); 817 818 /** 819 * Tracks and limits `seek()` calls to prevent accidental infinite loops. 820 * 821 * @since 6.2.0 822 * @var int 823 * 824 * @see WP_HTML_Tag_Processor::seek() 825 */ 826 protected $seek_count = 0; 827 828 /** 829 * Whether the parser should skip over an immediately-following linefeed 830 * character, as is the case with LISTING, PRE, and TEXTAREA. 831 * 832 * > If the next token is a U+000A LINE FEED (LF) character token, then 833 * > ignore that token and move on to the next one. (Newlines at the start 834 * > of [these] elements are ignored as an authoring convenience.) 835 * 836 * @since 6.7.0 837 * 838 * @var int|null 839 */ 840 private $skip_newline_at = null; 841 842 /** 843 * Constructor. 844 * 845 * @since 6.2.0 846 * 847 * @param string $html HTML to process. 848 */ 849 public function __construct( $html ) { 850 if ( ! is_string( $html ) ) { 851 _doing_it_wrong( 852 __METHOD__, 853 __( 'The HTML parameter must be a string.' ), 854 '6.9.0' 855 ); 856 $html = ''; 857 } 858 $this->html = $html; 859 } 860 861 /** 862 * Switches parsing mode into a new namespace, such as when 863 * encountering an SVG tag and entering foreign content. 864 * 865 * @since 6.7.0 866 * 867 * @param string $new_namespace One of 'html', 'svg', or 'math' indicating into what 868 * namespace the next tokens will be processed. 869 * @return bool Whether the namespace was valid and changed. 870 */ 871 public function change_parsing_namespace( string $new_namespace ): bool { 872 if ( ! in_array( $new_namespace, array( 'html', 'math', 'svg' ), true ) ) { 873 return false; 874 } 875 876 $this->parsing_namespace = $new_namespace; 877 return true; 878 } 879 880 /** 881 * Finds the next tag matching the $query. 882 * 883 * @since 6.2.0 884 * @since 6.5.0 No longer processes incomplete tokens at end of document; pauses the processor at start of token. 885 * 886 * @param array|string|null $query { 887 * Optional. Which tag name to find, having which class, etc. Default is to find any tag. 888 * 889 * @type string|null $tag_name Which tag to find, or `null` for "any tag." 890 * @type int|null $match_offset Find the Nth tag matching all search criteria. 891 * 1 for "first" tag, 3 for "third," etc. 892 * Defaults to first tag. 893 * @type string|null $class_name Tag must contain this whole class name to match. 894 * @type string|null $tag_closers "visit" or "skip": whether to stop on tag closers, e.g. </div>. 895 * } 896 * @return bool Whether a tag was matched. 897 * 898 * @phpstan-impure 899 */ 900 public function next_tag( $query = null ): bool { 901 $this->parse_query( $query ); 902 $already_found = 0; 903 904 do { 905 if ( false === $this->next_token() ) { 906 return false; 907 } 908 909 if ( self::STATE_MATCHED_TAG !== $this->parser_state ) { 910 continue; 911 } 912 913 if ( $this->matches() ) { 914 ++$already_found; 915 } 916 } while ( $already_found < $this->sought_match_offset ); 917 918 return true; 919 } 920 921 /** 922 * Finds the next token in the HTML document. 923 * 924 * An HTML document can be viewed as a stream of tokens, 925 * where tokens are things like HTML tags, HTML comments, 926 * text nodes, etc. This method finds the next token in 927 * the HTML document and returns whether it found one. 928 * 929 * If it starts parsing a token and reaches the end of the 930 * document then it will seek to the start of the last 931 * token and pause, returning `false` to indicate that it 932 * failed to find a complete token. 933 * 934 * Possible token types, based on the HTML specification: 935 * 936 * - an HTML tag, whether opening, closing, or void. 937 * - a text node - the plaintext inside tags. 938 * - an HTML comment. 939 * - a DOCTYPE declaration. 940 * - an HTML processing instruction, e.g. `<?pi …data?>`. 941 * 942 * @since 6.5.0 943 * @since 6.7.0 Recognizes CDATA sections within foreign content. 944 * @since 7.1.0 Recognizes processing instructions. 945 * 946 * @return bool Whether a token was parsed. 947 */ 948 public function next_token(): bool { 949 return $this->base_class_next_token(); 950 } 951 952 /** 953 * Internal method which finds the next token in the HTML document. 954 * 955 * This method is a protected internal function which implements the logic for 956 * finding the next token in a document. It exists so that the parser can update 957 * its state without affecting the location of the cursor in the document and 958 * without triggering subclass methods for things like `next_token()`, e.g. when 959 * applying patches before searching for the next token. 960 * 961 * @since 6.5.0 962 * @ignore 963 * 964 * @return bool Whether a token was parsed. 965 */ 966 private function base_class_next_token(): bool { 967 $was_at = $this->bytes_already_parsed; 968 $this->after_tag(); 969 970 // Don't proceed if there's nothing more to scan. 971 if ( 972 self::STATE_COMPLETE === $this->parser_state || 973 self::STATE_INCOMPLETE_INPUT === $this->parser_state 974 ) { 975 return false; 976 } 977 978 /* 979 * The next step in the parsing loop determines the parsing state; 980 * clear it so that state doesn't linger from the previous step. 981 */ 982 $this->parser_state = self::STATE_READY; 983 984 if ( $this->bytes_already_parsed >= strlen( $this->html ) ) { 985 $this->parser_state = self::STATE_COMPLETE; 986 return false; 987 } 988 989 // Find the next tag if it exists. 990 if ( false === $this->parse_next_tag() ) { 991 if ( self::STATE_INCOMPLETE_INPUT === $this->parser_state ) { 992 $this->bytes_already_parsed = $was_at; 993 } 994 995 return false; 996 } 997 998 /* 999 * For legacy reasons the rest of this function handles tags and their 1000 * attributes. If the processor has reached the end of the document 1001 * or if it matched any other token then it should return here to avoid 1002 * attempting to process tag-specific syntax. 1003 */ 1004 if ( 1005 self::STATE_INCOMPLETE_INPUT !== $this->parser_state && 1006 self::STATE_COMPLETE !== $this->parser_state && 1007 self::STATE_MATCHED_TAG !== $this->parser_state 1008 ) { 1009 return true; 1010 } 1011 1012 // Parse all of its attributes. 1013 while ( $this->parse_next_attribute() ) { 1014 continue; 1015 } 1016 1017 // Ensure that the tag closes before the end of the document. 1018 if ( 1019 self::STATE_INCOMPLETE_INPUT === $this->parser_state || 1020 $this->bytes_already_parsed >= strlen( $this->html ) 1021 ) { 1022 // Does this appropriately clear state (parsed attributes)? 1023 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 1024 $this->bytes_already_parsed = $was_at; 1025 1026 return false; 1027 } 1028 1029 $tag_ends_at = strpos( $this->html, '>', $this->bytes_already_parsed ); 1030 if ( false === $tag_ends_at ) { 1031 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 1032 $this->bytes_already_parsed = $was_at; 1033 1034 return false; 1035 } 1036 $this->parser_state = self::STATE_MATCHED_TAG; 1037 $this->bytes_already_parsed = $tag_ends_at + 1; 1038 $this->token_length = $this->bytes_already_parsed - $this->token_starts_at; 1039 1040 /* 1041 * Certain tags require additional processing. The first-letter pre-check 1042 * avoids unnecessary string allocation when comparing the tag names. 1043 * 1044 * - IFRAME 1045 * - LISTING (deprecated) 1046 * - NOEMBED (deprecated) 1047 * - NOFRAMES (deprecated) 1048 * - PRE 1049 * - SCRIPT 1050 * - STYLE 1051 * - TEXTAREA 1052 * - TITLE 1053 * - XMP (deprecated) 1054 */ 1055 if ( 1056 $this->is_closing_tag || 1057 'html' !== $this->parsing_namespace || 1058 1 !== strspn( $this->html, 'iIlLnNpPsStTxX', $this->tag_name_starts_at, 1 ) 1059 ) { 1060 return true; 1061 } 1062 1063 $tag_name = $this->get_tag(); 1064 1065 /* 1066 * For LISTING, PRE, and TEXTAREA, the first linefeed of an immediately-following 1067 * text node is ignored as an authoring convenience. 1068 * 1069 * @see static::skip_newline_at 1070 */ 1071 if ( 'LISTING' === $tag_name || 'PRE' === $tag_name ) { 1072 $this->skip_newline_at = $this->bytes_already_parsed; 1073 return true; 1074 } 1075 1076 /* 1077 * There are certain elements whose children are not DATA but are instead 1078 * RCDATA or RAWTEXT. These cannot contain other elements, and the contents 1079 * are parsed as plaintext, with character references decoded in RCDATA but 1080 * not in RAWTEXT. 1081 * 1082 * These elements are described here as "self-contained" or special atomic 1083 * elements whose end tag is consumed with the opening tag, and they will 1084 * contain modifiable text inside of them. 1085 * 1086 * Preserve the opening tag pointers, as these will be overwritten 1087 * when finding the closing tag. They will be reset after finding 1088 * the closing tag to point to the opening of the special atomic 1089 * tag sequence. 1090 */ 1091 $tag_name_starts_at = $this->tag_name_starts_at; 1092 $tag_name_length = $this->tag_name_length; 1093 $tag_ends_at = $this->token_starts_at + $this->token_length; 1094 $has_self_closing_flag = $this->has_self_closing_flag; 1095 $attributes = $this->attributes; 1096 $duplicate_attributes = $this->duplicate_attributes; 1097 1098 // Find the closing tag if necessary. 1099 switch ( $tag_name ) { 1100 case 'SCRIPT': 1101 $found_closer = $this->skip_script_data(); 1102 break; 1103 1104 case 'TEXTAREA': 1105 case 'TITLE': 1106 $found_closer = $this->skip_rcdata( $tag_name ); 1107 break; 1108 1109 /* 1110 * In the browser this list would include the NOSCRIPT element, 1111 * but the Tag Processor is an environment with the scripting 1112 * flag disabled, meaning that it needs to descend into the 1113 * NOSCRIPT element to be able to properly process what will be 1114 * sent to a browser. 1115 * 1116 * Note that this rule makes HTML5 syntax incompatible with XML, 1117 * because the parsing of this token depends on client application. 1118 * The NOSCRIPT element cannot be represented in the XHTML syntax. 1119 */ 1120 case 'IFRAME': 1121 case 'NOEMBED': 1122 case 'NOFRAMES': 1123 case 'STYLE': 1124 case 'XMP': 1125 $found_closer = $this->skip_rawtext( $tag_name ); 1126 break; 1127 1128 // No other tags should be treated in their entirety here. 1129 default: 1130 return true; 1131 } 1132 1133 if ( ! $found_closer ) { 1134 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 1135 $this->bytes_already_parsed = $was_at; 1136 return false; 1137 } 1138 1139 /* 1140 * The values here look like they reference the opening tag but they reference 1141 * the closing tag instead. This is why the opening tag values were stored 1142 * above in a variable. It reads confusingly here, but that's because the 1143 * functions that skip the contents have moved all the internal cursors past 1144 * the inner content of the tag. 1145 */ 1146 $this->token_starts_at = $was_at; 1147 $this->token_length = $this->bytes_already_parsed - $this->token_starts_at; 1148 $this->text_starts_at = $tag_ends_at; 1149 $this->text_length = $this->tag_name_starts_at - $this->text_starts_at; 1150 $this->tag_name_starts_at = $tag_name_starts_at; 1151 $this->tag_name_length = $tag_name_length; 1152 $this->has_self_closing_flag = $has_self_closing_flag; 1153 $this->attributes = $attributes; 1154 $this->duplicate_attributes = $duplicate_attributes; 1155 1156 return true; 1157 } 1158 1159 /** 1160 * Whether the processor paused because the input HTML document ended 1161 * in the middle of a syntax element, such as in the middle of a tag. 1162 * 1163 * Example: 1164 * 1165 * $processor = new WP_HTML_Tag_Processor( '<input type="text" value="Th' ); 1166 * false === $processor->next_tag(); 1167 * true === $processor->paused_at_incomplete_token(); 1168 * 1169 * @since 6.5.0 1170 * 1171 * @return bool Whether the parse paused at the start of an incomplete token. 1172 */ 1173 public function paused_at_incomplete_token(): bool { 1174 return self::STATE_INCOMPLETE_INPUT === $this->parser_state; 1175 } 1176 1177 /** 1178 * Generator for a foreach loop to step through each class name for the matched tag. 1179 * 1180 * This generator function is designed to be used inside a "foreach" loop. 1181 * 1182 * ```php interactive 1183 * $p = new WP_HTML_Tag_Processor( "<div class='free <egg>\tlang-en'>" ); 1184 * $p->next_tag(); 1185 * foreach ( $p->class_list() as $class_name ) { 1186 * echo "{$class_name} "; 1187 * } 1188 * // Outputs: "free <egg> lang-en " 1189 * ``` 1190 * 1191 * @since 6.4.0 1192 * 1193 * @return Generator<int, non-empty-string> 1194 */ 1195 public function class_list() { 1196 if ( self::STATE_MATCHED_TAG !== $this->parser_state ) { 1197 return; 1198 } 1199 1200 /** @var string $class contains the string value of the class attribute, with character references decoded. */ 1201 $class = $this->get_attribute( 'class' ); 1202 1203 if ( ! is_string( $class ) ) { 1204 return; 1205 } 1206 1207 $seen = array(); 1208 1209 $is_quirks = self::QUIRKS_MODE === $this->compat_mode; 1210 1211 $at = 0; 1212 while ( $at < strlen( $class ) ) { 1213 // Skip past any initial boundary characters. 1214 $at += strspn( $class, " \t\f\r\n", $at ); 1215 if ( $at >= strlen( $class ) ) { 1216 return; 1217 } 1218 1219 // Find the byte length until the next boundary. 1220 $length = strcspn( $class, " \t\f\r\n", $at ); 1221 if ( 0 === $length ) { 1222 return; 1223 } 1224 1225 $name = substr( $class, $at, $length ); 1226 if ( $is_quirks ) { 1227 $name = strtolower( $name ); 1228 } 1229 $at += $length; 1230 1231 /* 1232 * It's expected that the number of class names for a given tag is relatively small. 1233 * Given this, it is probably faster overall to scan an array for a value rather 1234 * than to use the class name as a key and check if it's a key of $seen. 1235 */ 1236 if ( in_array( $name, $seen, true ) ) { 1237 continue; 1238 } 1239 1240 $seen[] = $name; 1241 yield $name; 1242 } 1243 } 1244 1245 1246 /** 1247 * Returns if a matched tag contains the given ASCII case-insensitive class name. 1248 * 1249 * @since 6.4.0 1250 * 1251 * @param string $wanted_class Look for this CSS class name, ASCII case-insensitive. 1252 * @return bool|null Whether the matched tag contains the given class name, or null if not matched. 1253 */ 1254 public function has_class( $wanted_class ): ?bool { 1255 if ( self::STATE_MATCHED_TAG !== $this->parser_state ) { 1256 return null; 1257 } 1258 1259 $case_insensitive = self::QUIRKS_MODE === $this->compat_mode; 1260 1261 $wanted_length = strlen( $wanted_class ); 1262 foreach ( $this->class_list() as $class_name ) { 1263 if ( 1264 strlen( $class_name ) === $wanted_length && 1265 0 === substr_compare( $class_name, $wanted_class, 0, strlen( $wanted_class ), $case_insensitive ) 1266 ) { 1267 return true; 1268 } 1269 } 1270 1271 return false; 1272 } 1273 1274 1275 /** 1276 * Sets a bookmark in the HTML document. 1277 * 1278 * Bookmarks represent specific places or tokens in the HTML 1279 * document, such as a tag opener or closer. When applying 1280 * edits to a document, such as setting an attribute, the 1281 * text offsets of that token may shift; the bookmark is 1282 * kept updated with those shifts and remains stable unless 1283 * the entire span of text in which the token sits is removed. 1284 * 1285 * Release bookmarks when they are no longer needed. 1286 * 1287 * Example: 1288 * 1289 * <main><h2>Surprising fact you may not know!</h2></main> 1290 * ^ ^ 1291 * \-|-- this `H2` opener bookmark tracks the token 1292 * 1293 * <main class="clickbait"><h2>Surprising fact you may no… 1294 * ^ ^ 1295 * \-|-- it shifts with edits 1296 * 1297 * Bookmarks provide the ability to seek to a previously-scanned 1298 * place in the HTML document. This avoids the need to re-scan 1299 * the entire document. 1300 * 1301 * Example: 1302 * 1303 * <ul><li>One</li><li>Two</li><li>Three</li></ul> 1304 * ^^^^ 1305 * want to note this last item 1306 * 1307 * $p = new WP_HTML_Tag_Processor( $html ); 1308 * $in_list = false; 1309 * while ( $p->next_tag( array( 'tag_closers' => $in_list ? 'visit' : 'skip' ) ) ) { 1310 * if ( 'UL' === $p->get_tag() ) { 1311 * if ( $p->is_tag_closer() ) { 1312 * $in_list = false; 1313 * $p->set_bookmark( 'resume' ); 1314 * if ( $p->seek( 'last-li' ) ) { 1315 * $p->add_class( 'last-li' ); 1316 * } 1317 * $p->seek( 'resume' ); 1318 * $p->release_bookmark( 'last-li' ); 1319 * $p->release_bookmark( 'resume' ); 1320 * } else { 1321 * $in_list = true; 1322 * } 1323 * } 1324 * 1325 * if ( 'LI' === $p->get_tag() ) { 1326 * $p->set_bookmark( 'last-li' ); 1327 * } 1328 * } 1329 * 1330 * Bookmarks intentionally hide the internal string offsets 1331 * to which they refer. They are maintained internally as 1332 * updates are applied to the HTML document and therefore 1333 * retain their "position" - the location to which they 1334 * originally pointed. The inability to use bookmarks with 1335 * functions like `substr` is therefore intentional to guard 1336 * against accidentally breaking the HTML. 1337 * 1338 * Because bookmarks allocate memory and require processing 1339 * for every applied update, they are limited and require 1340 * a name. They should not be created with programmatically-made 1341 * names, such as "li_{$index}" with some loop. As a general 1342 * rule they should only be created with string-literal names 1343 * like "start-of-section" or "last-paragraph". 1344 * 1345 * Bookmarks are a powerful tool to enable complicated behavior. 1346 * Consider double-checking that you need this tool if you are 1347 * reaching for it, as inappropriate use could lead to broken 1348 * HTML structure or unwanted processing overhead. 1349 * 1350 * @since 6.2.0 1351 * 1352 * @param string $name Identifies this particular bookmark. 1353 * @return bool Whether the bookmark was successfully created. 1354 */ 1355 public function set_bookmark( $name ): bool { 1356 // It only makes sense to set a bookmark if the parser has paused on a concrete token. 1357 if ( 1358 self::STATE_COMPLETE === $this->parser_state || 1359 self::STATE_INCOMPLETE_INPUT === $this->parser_state 1360 ) { 1361 return false; 1362 } 1363 1364 if ( ! array_key_exists( $name, $this->bookmarks ) && count( $this->bookmarks ) >= static::MAX_BOOKMARKS ) { 1365 _doing_it_wrong( 1366 __METHOD__, 1367 __( 'Too many bookmarks: cannot create any more.' ), 1368 '6.2.0' 1369 ); 1370 return false; 1371 } 1372 1373 $this->bookmarks[ $name ] = new WP_HTML_Span( $this->token_starts_at, $this->token_length ); 1374 1375 return true; 1376 } 1377 1378 1379 /** 1380 * Removes a bookmark that is no longer needed. 1381 * 1382 * Releasing a bookmark frees up the small 1383 * performance overhead it requires. 1384 * 1385 * @since 6.2.0 1386 * 1387 * @param string $name Name of the bookmark to remove. 1388 * @return bool Whether the bookmark already existed before removal. 1389 */ 1390 public function release_bookmark( $name ): bool { 1391 if ( ! array_key_exists( $name, $this->bookmarks ) ) { 1392 return false; 1393 } 1394 1395 unset( $this->bookmarks[ $name ] ); 1396 1397 return true; 1398 } 1399 1400 /** 1401 * Skips contents of generic rawtext elements. 1402 * 1403 * @since 6.3.2 1404 * @ignore 1405 * 1406 * @see https://html.spec.whatwg.org/#generic-raw-text-element-parsing-algorithm 1407 * 1408 * @param string $tag_name The uppercase tag name which will close the RAWTEXT region. 1409 * @return bool Whether an end to the RAWTEXT region was found before the end of the document. 1410 */ 1411 private function skip_rawtext( string $tag_name ): bool { 1412 /* 1413 * These two functions distinguish themselves on whether character references are 1414 * decoded, and since functionality to read the inner markup isn't supported, it's 1415 * not necessary to implement these two functions separately. 1416 */ 1417 return $this->skip_rcdata( $tag_name ); 1418 } 1419 1420 /** 1421 * Skips contents of RCDATA elements, namely title and textarea tags. 1422 * 1423 * @since 6.2.0 1424 * @ignore 1425 * 1426 * @see https://html.spec.whatwg.org/multipage/parsing.html#rcdata-state 1427 * 1428 * @param string $tag_name The uppercase tag name which will close the RCDATA region. 1429 * @return bool Whether an end to the RCDATA region was found before the end of the document. 1430 */ 1431 private function skip_rcdata( string $tag_name ): bool { 1432 $html = $this->html; 1433 $doc_length = strlen( $html ); 1434 $tag_length = strlen( $tag_name ); 1435 1436 $at = $this->bytes_already_parsed; 1437 1438 while ( false !== $at && $at < $doc_length ) { 1439 $at = strpos( $this->html, '</', $at ); 1440 $this->tag_name_starts_at = $at; 1441 1442 // Fail if there is no possible tag closer. 1443 if ( false === $at || ( $at + 2 + $tag_length ) >= $doc_length ) { 1444 return false; 1445 } 1446 1447 $at += 2; 1448 1449 /* 1450 * Find a case-insensitive match to the tag name. 1451 * 1452 * Because tag names are limited to US-ASCII there is no 1453 * need to perform any kind of Unicode normalization when 1454 * comparing; any character which could be impacted by such 1455 * normalization could not be part of a tag name. 1456 */ 1457 for ( $i = 0; $i < $tag_length; $i++ ) { 1458 $tag_char = $tag_name[ $i ]; 1459 $html_char = $html[ $at + $i ]; 1460 1461 if ( $html_char !== $tag_char && strtoupper( $html_char ) !== $tag_char ) { 1462 $at += $i; 1463 continue 2; 1464 } 1465 } 1466 1467 $at += $tag_length; 1468 $this->bytes_already_parsed = $at; 1469 1470 if ( $at >= strlen( $html ) ) { 1471 return false; 1472 } 1473 1474 /* 1475 * Ensure that the tag name terminates to avoid matching on 1476 * substrings of a longer tag name. For example, the sequence 1477 * "</textarearug" should not match for "</textarea" even 1478 * though "textarea" is found within the text. 1479 */ 1480 $c = $html[ $at ]; 1481 if ( ' ' !== $c && "\t" !== $c && "\f" !== $c && "\r" !== $c && "\n" !== $c && '/' !== $c && '>' !== $c ) { 1482 continue; 1483 } 1484 1485 while ( $this->parse_next_attribute() ) { 1486 continue; 1487 } 1488 1489 $at = $this->bytes_already_parsed; 1490 if ( $at >= strlen( $this->html ) ) { 1491 return false; 1492 } 1493 1494 if ( '>' === $html[ $at ] ) { 1495 $this->bytes_already_parsed = $at + 1; 1496 return true; 1497 } 1498 1499 if ( $at + 1 >= strlen( $this->html ) ) { 1500 return false; 1501 } 1502 1503 if ( '/' === $html[ $at ] && '>' === $html[ $at + 1 ] ) { 1504 $this->bytes_already_parsed = $at + 2; 1505 return true; 1506 } 1507 } 1508 1509 return false; 1510 } 1511 1512 /** 1513 * Skips contents of script tags. 1514 * 1515 * @since 6.2.0 1516 * @ignore 1517 * 1518 * @return bool Whether the script tag was closed before the end of the document. 1519 */ 1520 private function skip_script_data(): bool { 1521 $state = 'unescaped'; 1522 $html = $this->html; 1523 $doc_length = strlen( $html ); 1524 $at = $this->bytes_already_parsed; 1525 1526 while ( false !== $at && $at < $doc_length ) { 1527 $at += strcspn( $html, '-<', $at ); 1528 1529 /* 1530 * Optimization: Terminating a complete script element requires at least eight 1531 * additional bytes in the document. Some checks below may cause local escaped 1532 * state transitions when processing shorter strings, but those transitions are 1533 * irrelevant if the script tag is incomplete and the function must return false. 1534 * 1535 * This may need updating if those transitions become significant or exported from 1536 * this function in some way, such as when building safe methods to embed JavaScript 1537 * or data inside a SCRIPT element. 1538 * 1539 * $at may be here. 1540 * ↓ 1541 * ...</script> 1542 * ╰──┬───╯ 1543 * $at + 8 additional bytes are required for a non-false return value. 1544 * 1545 * This single check eliminates the need to check lengths for the shorter spans: 1546 * 1547 * $at may be here. 1548 * ↓ 1549 * <script><!-- --></script> 1550 * ├╯ 1551 * $at + 2 additional characters does not require a length check. 1552 * 1553 * The transition from "escaped" to "unescaped" is not relevant if the document ends: 1554 * 1555 * $at may be here. 1556 * ↓ 1557 * <script><!-- -->[[END-OF-DOCUMENT]] 1558 * ╰──┬───╯ 1559 * $at + 8 additional bytes is not satisfied, return false. 1560 */ 1561 if ( $at + 8 >= $doc_length ) { 1562 return false; 1563 } 1564 1565 /* 1566 * For all script states a "-->" transitions 1567 * back into the normal unescaped script mode, 1568 * even if that's the current state. 1569 */ 1570 if ( 1571 '-' === $html[ $at ] && 1572 '-' === $html[ $at + 1 ] && 1573 '>' === $html[ $at + 2 ] 1574 ) { 1575 $at += 3; 1576 $state = 'unescaped'; 1577 continue; 1578 } 1579 1580 /* 1581 * Everything of interest past here starts with "<". 1582 * Check this character and advance position regardless. 1583 */ 1584 if ( '<' !== $html[ $at++ ] ) { 1585 continue; 1586 } 1587 1588 /* 1589 * "<!--" only transitions from _unescaped_ to _escaped_. This byte sequence is only 1590 * significant in the _unescaped_ state and is ignored in any other state. 1591 */ 1592 if ( 1593 'unescaped' === $state && 1594 '!' === $html[ $at ] && 1595 '-' === $html[ $at + 1 ] && 1596 '-' === $html[ $at + 2 ] 1597 ) { 1598 $at += 3; 1599 1600 /* 1601 * The parser is ready to enter the _escaped_ state, but may remain in the 1602 * _unescaped_ state. This occurs when "<!--" is immediately followed by a 1603 * sequence of 0 or more "-" followed by ">". This is similar to abruptly closed 1604 * HTML comments like "<!-->" or "<!--->". 1605 * 1606 * Note that this check may advance the position significantly and requires a 1607 * length check to prevent bad offsets on inputs like `<script><!---------`. 1608 */ 1609 $at += strspn( $html, '-', $at ); 1610 if ( $at < $doc_length && '>' === $html[ $at ] ) { 1611 ++$at; 1612 continue; 1613 } 1614 1615 $state = 'escaped'; 1616 continue; 1617 } 1618 1619 if ( '/' === $html[ $at ] ) { 1620 $closer_potentially_starts_at = $at - 1; 1621 $is_closing = true; 1622 ++$at; 1623 } else { 1624 $is_closing = false; 1625 } 1626 1627 /* 1628 * At this point the only remaining state-changes occur with the 1629 * <script> and </script> tags; unless one of these appears next, 1630 * proceed scanning to the next potential token in the text. 1631 */ 1632 if ( ! ( 1633 ( 's' === $html[ $at ] || 'S' === $html[ $at ] ) && 1634 ( 'c' === $html[ $at + 1 ] || 'C' === $html[ $at + 1 ] ) && 1635 ( 'r' === $html[ $at + 2 ] || 'R' === $html[ $at + 2 ] ) && 1636 ( 'i' === $html[ $at + 3 ] || 'I' === $html[ $at + 3 ] ) && 1637 ( 'p' === $html[ $at + 4 ] || 'P' === $html[ $at + 4 ] ) && 1638 ( 't' === $html[ $at + 5 ] || 'T' === $html[ $at + 5 ] ) 1639 ) ) { 1640 continue; 1641 } 1642 1643 /* 1644 * Ensure that the script tag terminates to avoid matching on 1645 * substrings of a non-match. For example, the sequence 1646 * "<script123" should not end a script region even though 1647 * "<script" is found within the text. 1648 */ 1649 $at += 6; 1650 $c = $html[ $at ]; 1651 if ( 1652 /** 1653 * These characters trigger state transitions of interest: 1654 * 1655 * - @see {https://html.spec.whatwg.org/multipage/parsing.html#script-data-end-tag-name-state} 1656 * - @see {https://html.spec.whatwg.org/multipage/parsing.html#script-data-escaped-end-tag-name-state} 1657 * - @see {https://html.spec.whatwg.org/multipage/parsing.html#script-data-double-escape-start-state} 1658 * - @see {https://html.spec.whatwg.org/multipage/parsing.html#script-data-double-escape-end-state} 1659 * 1660 * The "\r" character is not present in the above references. However, "\r" must be 1661 * treated the same as "\n". This is because the HTML Standard requires newline 1662 * normalization during preprocessing which applies this replacement. 1663 * 1664 * - @see https://html.spec.whatwg.org/multipage/parsing.html#preprocessing-the-input-stream 1665 * - @see https://infra.spec.whatwg.org/#normalize-newlines 1666 */ 1667 '>' !== $c && 1668 ' ' !== $c && 1669 "\n" !== $c && 1670 '/' !== $c && 1671 "\t" !== $c && 1672 "\f" !== $c && 1673 "\r" !== $c 1674 ) { 1675 continue; 1676 } 1677 1678 if ( 'escaped' === $state && ! $is_closing ) { 1679 $state = 'double-escaped'; 1680 continue; 1681 } 1682 1683 if ( 'double-escaped' === $state && $is_closing ) { 1684 $state = 'escaped'; 1685 continue; 1686 } 1687 1688 if ( $is_closing ) { 1689 $this->bytes_already_parsed = $closer_potentially_starts_at; 1690 $this->tag_name_starts_at = $closer_potentially_starts_at; 1691 if ( $this->bytes_already_parsed >= $doc_length ) { 1692 return false; 1693 } 1694 1695 while ( $this->parse_next_attribute() ) { 1696 continue; 1697 } 1698 1699 if ( $this->bytes_already_parsed >= $doc_length ) { 1700 return false; 1701 } 1702 1703 if ( '>' === $html[ $this->bytes_already_parsed ] ) { 1704 ++$this->bytes_already_parsed; 1705 return true; 1706 } 1707 } 1708 1709 ++$at; 1710 } 1711 1712 return false; 1713 } 1714 1715 /** 1716 * Parses the next tag. 1717 * 1718 * This will find and start parsing the next tag, including 1719 * the opening `<`, the potential closer `/`, and the tag 1720 * name. It does not parse the attributes or scan to the 1721 * closing `>`; these are left for other methods. 1722 * 1723 * @since 6.2.0 1724 * @since 6.2.1 Support abruptly-closed comments, invalid-tag-closer-comments, and empty elements. 1725 * @ignore 1726 * 1727 * @return bool Whether a tag was found before the end of the document. 1728 * 1729 * @phpstan-impure 1730 */ 1731 private function parse_next_tag(): bool { 1732 $this->after_tag(); 1733 1734 $html = $this->html; 1735 $doc_length = strlen( $html ); 1736 $was_at = $this->bytes_already_parsed; 1737 $at = $was_at; 1738 1739 while ( $at < $doc_length ) { 1740 $at = strpos( $html, '<', $at ); 1741 if ( false === $at ) { 1742 break; 1743 } 1744 1745 if ( $at > $was_at ) { 1746 /* 1747 * A "<" normally starts a new HTML tag or syntax token, but in cases where the 1748 * following character can't produce a valid token, the "<" is instead treated 1749 * as plaintext and the parser should skip over it. This avoids a problem when 1750 * following earlier practices of typing emoji with text, e.g. "<3". This 1751 * should be a heart, not a tag. It's supposed to be rendered, not hidden. 1752 * 1753 * At this point the parser checks if this is one of those cases and if it is 1754 * will continue searching for the next "<" in search of a token boundary. 1755 * 1756 * @see https://html.spec.whatwg.org/#tag-open-state 1757 */ 1758 if ( 1 !== strspn( $html, '!/?abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ', $at + 1, 1 ) ) { 1759 ++$at; 1760 continue; 1761 } 1762 1763 $this->parser_state = self::STATE_TEXT_NODE; 1764 $this->token_starts_at = $was_at; 1765 $this->token_length = $at - $was_at; 1766 $this->text_starts_at = $was_at; 1767 $this->text_length = $this->token_length; 1768 $this->bytes_already_parsed = $at; 1769 return true; 1770 } 1771 1772 $this->token_starts_at = $at; 1773 1774 if ( $at + 1 < $doc_length && '/' === $this->html[ $at + 1 ] ) { 1775 $this->is_closing_tag = true; 1776 ++$at; 1777 } else { 1778 $this->is_closing_tag = false; 1779 } 1780 1781 /* 1782 * HTML tag names must start with [a-zA-Z] otherwise they are not tags. 1783 * For example, "<3" is rendered as text, not a tag opener. If at least 1784 * one letter follows the "<" then _it is_ a tag, but if the following 1785 * character is anything else it _is not a tag_. 1786 * 1787 * It's not uncommon to find non-tags starting with `<` in an HTML 1788 * document, so it's good for performance to make this pre-check before 1789 * continuing to attempt to parse a tag name. 1790 * 1791 * Reference: 1792 * * https://html.spec.whatwg.org/multipage/parsing.html#data-state 1793 * * https://html.spec.whatwg.org/multipage/parsing.html#tag-open-state 1794 */ 1795 $tag_name_prefix_length = strspn( $html, 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ', $at + 1 ); 1796 if ( $tag_name_prefix_length > 0 ) { 1797 ++$at; 1798 $this->parser_state = self::STATE_MATCHED_TAG; 1799 $this->tag_name_starts_at = $at; 1800 $this->tag_name_length = $tag_name_prefix_length + strcspn( $html, " \t\f\r\n/>", $at + $tag_name_prefix_length ); 1801 $this->bytes_already_parsed = $at + $this->tag_name_length; 1802 return true; 1803 } 1804 1805 /* 1806 * Abort if no tag is found before the end of 1807 * the document. There is nothing left to parse. 1808 */ 1809 if ( $at + 1 >= $doc_length ) { 1810 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 1811 1812 return false; 1813 } 1814 1815 /* 1816 * `<!` transitions to markup declaration open state 1817 * https://html.spec.whatwg.org/multipage/parsing.html#markup-declaration-open-state 1818 */ 1819 if ( ! $this->is_closing_tag && '!' === $html[ $at + 1 ] ) { 1820 /* 1821 * `<!--` transitions to a comment state – apply further comment rules. 1822 * https://html.spec.whatwg.org/multipage/parsing.html#tag-open-state 1823 */ 1824 if ( 0 === substr_compare( $html, '--', $at + 2, 2 ) ) { 1825 $closer_at = $at + 4; 1826 // If it's not possible to close the comment then there is nothing more to scan. 1827 if ( $doc_length <= $closer_at ) { 1828 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 1829 1830 return false; 1831 } 1832 1833 // Abruptly-closed empty comments are a sequence of dashes followed by `>`. 1834 $span_of_dashes = strspn( $html, '-', $closer_at ); 1835 if ( $doc_length <= $span_of_dashes + $closer_at ) { 1836 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 1837 1838 return false; 1839 } 1840 1841 if ( '>' === $html[ $closer_at + $span_of_dashes ] ) { 1842 /* 1843 * @todo When implementing `set_modifiable_text()` ensure that updates to this token 1844 * don't break the syntax for short comments, e.g. `<!--->`. Unlike other comment 1845 * and bogus comment syntax, these leave no clear insertion point for text and 1846 * they need to be modified specially in order to contain text. E.g. to store 1847 * `?` as the modifiable text, the `<!--->` needs to become `<!--?-->`, which 1848 * involves inserting an additional `-` into the token after the modifiable text. 1849 */ 1850 $this->parser_state = self::STATE_COMMENT; 1851 $this->comment_type = self::COMMENT_AS_ABRUPTLY_CLOSED_COMMENT; 1852 $this->token_length = $closer_at + $span_of_dashes + 1 - $this->token_starts_at; 1853 1854 // Only provide modifiable text if the token is long enough to contain it. 1855 if ( $span_of_dashes >= 2 ) { 1856 $this->comment_type = self::COMMENT_AS_HTML_COMMENT; 1857 $this->text_starts_at = $this->token_starts_at + 4; 1858 $this->text_length = $span_of_dashes - 2; 1859 } 1860 1861 $this->bytes_already_parsed = $closer_at + $span_of_dashes + 1; 1862 return true; 1863 } 1864 1865 /* 1866 * Comments may be closed by either a --> or an invalid --!>. 1867 * The first occurrence closes the comment. 1868 * 1869 * See https://html.spec.whatwg.org/#parse-error-incorrectly-closed-comment 1870 */ 1871 --$closer_at; // Pre-increment inside condition below reduces risk of accidental infinite looping. 1872 while ( ++$closer_at < $doc_length ) { 1873 $closer_at = strpos( $html, '--', $closer_at ); 1874 if ( false === $closer_at ) { 1875 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 1876 1877 return false; 1878 } 1879 1880 if ( $closer_at + 2 < $doc_length && '>' === $html[ $closer_at + 2 ] ) { 1881 $this->parser_state = self::STATE_COMMENT; 1882 $this->comment_type = self::COMMENT_AS_HTML_COMMENT; 1883 $this->token_length = $closer_at + 3 - $this->token_starts_at; 1884 $this->text_starts_at = $this->token_starts_at + 4; 1885 $this->text_length = $closer_at - $this->text_starts_at; 1886 $this->bytes_already_parsed = $closer_at + 3; 1887 return true; 1888 } 1889 1890 if ( 1891 $closer_at + 3 < $doc_length && 1892 '!' === $html[ $closer_at + 2 ] && 1893 '>' === $html[ $closer_at + 3 ] 1894 ) { 1895 $this->parser_state = self::STATE_COMMENT; 1896 $this->comment_type = self::COMMENT_AS_HTML_COMMENT; 1897 $this->token_length = $closer_at + 4 - $this->token_starts_at; 1898 $this->text_starts_at = $this->token_starts_at + 4; 1899 $this->text_length = $closer_at - $this->text_starts_at; 1900 $this->bytes_already_parsed = $closer_at + 4; 1901 return true; 1902 } 1903 } 1904 } 1905 1906 /* 1907 * `<!DOCTYPE` transitions to DOCTYPE state – skip to the nearest > 1908 * These are ASCII-case-insensitive. 1909 * https://html.spec.whatwg.org/multipage/parsing.html#tag-open-state 1910 */ 1911 if ( 1912 $doc_length > $at + 8 && 1913 ( 'D' === $html[ $at + 2 ] || 'd' === $html[ $at + 2 ] ) && 1914 ( 'O' === $html[ $at + 3 ] || 'o' === $html[ $at + 3 ] ) && 1915 ( 'C' === $html[ $at + 4 ] || 'c' === $html[ $at + 4 ] ) && 1916 ( 'T' === $html[ $at + 5 ] || 't' === $html[ $at + 5 ] ) && 1917 ( 'Y' === $html[ $at + 6 ] || 'y' === $html[ $at + 6 ] ) && 1918 ( 'P' === $html[ $at + 7 ] || 'p' === $html[ $at + 7 ] ) && 1919 ( 'E' === $html[ $at + 8 ] || 'e' === $html[ $at + 8 ] ) 1920 ) { 1921 $closer_at = strpos( $html, '>', $at + 9 ); 1922 if ( false === $closer_at ) { 1923 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 1924 1925 return false; 1926 } 1927 1928 $this->parser_state = self::STATE_DOCTYPE; 1929 $this->token_length = $closer_at + 1 - $this->token_starts_at; 1930 $this->text_starts_at = $this->token_starts_at + 9; 1931 $this->text_length = $closer_at - $this->text_starts_at; 1932 $this->bytes_already_parsed = $closer_at + 1; 1933 return true; 1934 } 1935 1936 if ( 1937 'html' !== $this->parsing_namespace && 1938 strlen( $html ) > $at + 8 && 1939 '[' === $html[ $at + 2 ] && 1940 'C' === $html[ $at + 3 ] && 1941 'D' === $html[ $at + 4 ] && 1942 'A' === $html[ $at + 5 ] && 1943 'T' === $html[ $at + 6 ] && 1944 'A' === $html[ $at + 7 ] && 1945 '[' === $html[ $at + 8 ] 1946 ) { 1947 $closer_at = strpos( $html, ']]>', $at + 9 ); 1948 if ( false === $closer_at ) { 1949 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 1950 1951 return false; 1952 } 1953 1954 $this->parser_state = self::STATE_CDATA_NODE; 1955 $this->text_starts_at = $at + 9; 1956 $this->text_length = $closer_at - $this->text_starts_at; 1957 $this->token_length = $closer_at + 3 - $this->token_starts_at; 1958 $this->bytes_already_parsed = $closer_at + 3; 1959 return true; 1960 } 1961 1962 /* 1963 * Anything else here is an incorrectly-opened comment and transitions 1964 * to the bogus comment state - skip to the nearest >. If no closer is 1965 * found then the HTML was truncated inside the markup declaration. 1966 */ 1967 $closer_at = strpos( $html, '>', $at + 1 ); 1968 if ( false === $closer_at ) { 1969 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 1970 1971 return false; 1972 } 1973 1974 $this->parser_state = self::STATE_COMMENT; 1975 $this->comment_type = self::COMMENT_AS_INVALID_HTML; 1976 $this->token_length = $closer_at + 1 - $this->token_starts_at; 1977 $this->text_starts_at = $this->token_starts_at + 2; 1978 $this->text_length = $closer_at - $this->text_starts_at; 1979 $this->bytes_already_parsed = $closer_at + 1; 1980 1981 /* 1982 * Identify nodes that would be CDATA if HTML had CDATA sections. 1983 * 1984 * This section must occur after identifying the bogus comment end 1985 * because in an HTML parser it will span to the nearest `>`, even 1986 * if there's no `]]>` as would be required in an XML document. It 1987 * is therefore not possible to parse a CDATA section containing 1988 * a `>` in the HTML syntax. 1989 * 1990 * Inside foreign elements there is a discrepancy between browsers 1991 * and the specification on this. 1992 * 1993 * @todo Track whether the Tag Processor is inside a foreign element 1994 * and require the proper closing `]]>` in those cases. 1995 */ 1996 if ( 1997 $this->token_length >= 10 && 1998 '[' === $html[ $this->token_starts_at + 2 ] && 1999 'C' === $html[ $this->token_starts_at + 3 ] && 2000 'D' === $html[ $this->token_starts_at + 4 ] && 2001 'A' === $html[ $this->token_starts_at + 5 ] && 2002 'T' === $html[ $this->token_starts_at + 6 ] && 2003 'A' === $html[ $this->token_starts_at + 7 ] && 2004 '[' === $html[ $this->token_starts_at + 8 ] && 2005 ']' === $html[ $closer_at - 1 ] && 2006 ']' === $html[ $closer_at - 2 ] 2007 ) { 2008 $this->parser_state = self::STATE_COMMENT; 2009 $this->comment_type = self::COMMENT_AS_CDATA_LOOKALIKE; 2010 $this->text_starts_at += 7; 2011 $this->text_length -= 9; 2012 } 2013 2014 return true; 2015 } 2016 2017 /* 2018 * </> is a missing end tag name, which is ignored. 2019 * 2020 * This was also known as the "presumptuous empty tag" 2021 * in early discussions as it was proposed to close 2022 * the nearest previous opening tag. 2023 * 2024 * See https://html.spec.whatwg.org/#parse-error-missing-end-tag-name 2025 */ 2026 if ( '>' === $html[ $at + 1 ] ) { 2027 // `<>` is interpreted as plaintext. 2028 if ( ! $this->is_closing_tag ) { 2029 ++$at; 2030 continue; 2031 } 2032 2033 $this->parser_state = self::STATE_PRESUMPTUOUS_TAG; 2034 $this->token_length = $at + 2 - $this->token_starts_at; 2035 $this->bytes_already_parsed = $at + 2; 2036 return true; 2037 } 2038 2039 /** 2040 * `<?` transitions to the processing instruction open state. 2041 * 2042 * A processing instruction whose target starts with an ASCII letter or `_`, 2043 * continues with ASCII alphanumerics, `-`, or `_`, and is not an ASCII 2044 * case-insensitive match for `xml` or `xml-stylesheet` produces a processing 2045 * instruction node. Anything else transitions to the bogus comment state. 2046 * 2047 * Both forms end at the nearest `>`; a processing instruction cannot 2048 * contain one in the HTML syntax. 2049 * 2050 * @link https://html.spec.whatwg.org/multipage/parsing.html#processing-instruction-open-state 2051 */ 2052 if ( ! $this->is_closing_tag && '?' === $html[ $at + 1 ] ) { 2053 $closer_at = strpos( $html, '>', $at + 2 ); 2054 if ( false === $closer_at ) { 2055 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 2056 2057 return false; 2058 } 2059 2060 $target_at = $at + 2; 2061 $target_length = 0; 2062 $first_char = $html[ $target_at ]; 2063 if ( 2064 ( 'a' <= $first_char && 'z' >= $first_char ) || 2065 ( 'A' <= $first_char && 'Z' >= $first_char ) || 2066 '_' === $first_char 2067 ) { 2068 $target_length = 1 + strspn( $html, 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_-', $target_at + 1 ); 2069 } 2070 2071 /* 2072 * In the processing instruction target state, only whitespace, `?`, 2073 * or `>` may terminate the target; any other character converts the 2074 * token into a bogus comment. 2075 * 2076 * The `xml` and `xml-stylesheet` targets are reserved and disallowed; 2077 * they also convert the token into a bogus comment. 2078 */ 2079 $is_valid_pi = ( 2080 0 !== $target_length && 2081 str_contains( " \t\f\r\n?>", $html[ $target_at + $target_length ] ) && 2082 ! ( 3 === $target_length && 0 === substr_compare( $html, 'xml', $target_at, 3, true ) ) && 2083 ! ( 14 === $target_length && 0 === substr_compare( $html, 'xml-stylesheet', $target_at, 14, true ) ) 2084 ); 2085 2086 if ( $is_valid_pi ) { 2087 /* 2088 * The processing instruction data starts after any whitespace 2089 * following the target and ends at the `>`. When the token is 2090 * closed by `?>`, that final `?` is not part of the data. 2091 */ 2092 $data_at = $target_at + $target_length; 2093 $data_at += strspn( $html, " \t\f\r\n", $data_at ); 2094 2095 $data_length = $closer_at - $data_at; 2096 if ( $data_length > 0 && '?' === $html[ $closer_at - 1 ] ) { 2097 --$data_length; 2098 } 2099 2100 $this->parser_state = self::STATE_PROCESSING_INSTRUCTION; 2101 $this->tag_name_starts_at = $target_at; 2102 $this->tag_name_length = $target_length; 2103 $this->token_length = $closer_at + 1 - $this->token_starts_at; 2104 $this->text_starts_at = $data_at; 2105 $this->text_length = $data_length; 2106 $this->bytes_already_parsed = $closer_at + 1; 2107 return true; 2108 } 2109 2110 $this->parser_state = self::STATE_COMMENT; 2111 $this->comment_type = self::COMMENT_AS_INVALID_HTML; 2112 $this->token_length = $closer_at + 1 - $this->token_starts_at; 2113 $this->text_starts_at = $this->token_starts_at + 2; 2114 $this->text_length = $closer_at - $this->text_starts_at; 2115 $this->bytes_already_parsed = $closer_at + 1; 2116 2117 /* 2118 * Identify an XML-like Processing Instruction node. 2119 * 2120 * HTML and XML processing instructions have different parsing rules. 2121 * The HTML API recognizes XML-like processing instructions that are 2122 * _not_ HTML processing instructions. The HTML standard transforms 2123 * them to "bogus comments," represented by the HTML API as comments 2124 * with the `COMMENT_AS_PI_NODE_LOOKALIKE` type. This includes the 2125 * special targets `xml` and `xml-stylesheet` which are reserved 2126 * targets not allowed in HTML processing instructions. 2127 * 2128 * > NameStartChar ::= ":" | [A-Z] | "_" | [a-z] | [#xC0-#xD6] | [#xD8-#xF6] | [#xF8-#x2FF] | 2129 * [#x370-#x37D] | [#x37F-#x1FFF] | [#x200C-#x200D] | [#x2070-#x218F] | 2130 * [#x2C00-#x2FEF] | [#x3001-#xD7FF] | [#xF900-#xFDCF] | [#xFDF0-#xFFFD] | 2131 * [#x10000-#xEFFFF] 2132 * > NameChar ::= NameStartChar | "-" | "." | [0-9] | #xB7 | [#x0300-#x036F] | [#x203F-#x2040] 2133 * 2134 * @see https://www.w3.org/TR/2006/REC-xml11-20060816/#NT-PITarget 2135 */ 2136 if ( $this->token_length >= 5 && '?' === $html[ $closer_at - 1 ] ) { 2137 $comment_text = substr( $html, $this->token_starts_at + 2, $this->token_length - 4 ); 2138 $pi_target_length = strspn( $comment_text, 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ:_' ); 2139 2140 if ( 0 < $pi_target_length ) { 2141 $pi_target_length += strspn( $comment_text, 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789:_-.', $pi_target_length ); 2142 2143 $this->comment_type = self::COMMENT_AS_PI_NODE_LOOKALIKE; 2144 $this->tag_name_starts_at = $this->token_starts_at + 2; 2145 $this->tag_name_length = $pi_target_length; 2146 $this->text_starts_at += $pi_target_length; 2147 $this->text_length -= $pi_target_length + 1; 2148 } 2149 } 2150 2151 return true; 2152 } 2153 2154 /* 2155 * If a non-alpha starts the tag name in a tag closer it's a comment. 2156 * Find the first `>`, which closes the comment. 2157 * 2158 * This parser classifies these particular comments as special "funky comments" 2159 * which are made available for further processing. 2160 * 2161 * See https://html.spec.whatwg.org/#parse-error-invalid-first-character-of-tag-name 2162 */ 2163 if ( $this->is_closing_tag ) { 2164 // No chance of finding a closer. 2165 if ( $at + 3 > $doc_length ) { 2166 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 2167 2168 return false; 2169 } 2170 2171 $closer_at = strpos( $html, '>', $at + 2 ); 2172 if ( false === $closer_at ) { 2173 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 2174 2175 return false; 2176 } 2177 2178 $this->parser_state = self::STATE_FUNKY_COMMENT; 2179 $this->token_length = $closer_at + 1 - $this->token_starts_at; 2180 $this->text_starts_at = $this->token_starts_at + 2; 2181 $this->text_length = $closer_at - $this->text_starts_at; 2182 $this->bytes_already_parsed = $closer_at + 1; 2183 return true; 2184 } 2185 2186 ++$at; 2187 } 2188 2189 /* 2190 * This does not imply an incomplete parse; it indicates that there 2191 * can be nothing left in the document other than a #text node. 2192 */ 2193 $this->parser_state = self::STATE_TEXT_NODE; 2194 $this->token_starts_at = $was_at; 2195 $this->token_length = $doc_length - $was_at; 2196 $this->text_starts_at = $was_at; 2197 $this->text_length = $this->token_length; 2198 $this->bytes_already_parsed = $doc_length; 2199 return true; 2200 } 2201 2202 /** 2203 * Parses the next attribute. 2204 * 2205 * @since 6.2.0 2206 * @ignore 2207 * 2208 * @return bool Whether an attribute was found. Returns `false` upon reaching the end 2209 * of the tag (`>` or `/>`) or the end of the document. 2210 */ 2211 private function parse_next_attribute(): bool { 2212 $doc_length = strlen( $this->html ); 2213 2214 // Skip whitespace and slashes. 2215 $skipped_length = strspn( $this->html, " \t\f\r\n/", $this->bytes_already_parsed ); 2216 $this->bytes_already_parsed += $skipped_length; 2217 if ( $this->bytes_already_parsed >= $doc_length ) { 2218 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 2219 2220 return false; 2221 } 2222 2223 /** 2224 * This block serves two purposes: 2225 * 2226 * - A fast path for common tag-ending `>`. 2227 * - A check for the self-closing flag which must appear as `/>`. 2228 * 2229 * In a tag like `<g attr=/>`, `/` is the attribute value, not a self-closing 2230 * flag. When it appears in this form, the parser has already consumed the 2231 * attribute value, `$skipped_length` is 0, and this checks below correctly 2232 * identify whether there is a self-closing flag. 2233 * 2234 * Note: Both start and end tags may have the self-closing flag. 2235 */ 2236 if ( '>' === $this->html[ $this->bytes_already_parsed ] ) { 2237 if ( $skipped_length > 0 && '/' === $this->html[ $this->bytes_already_parsed - 1 ] ) { 2238 $this->has_self_closing_flag = true; 2239 } 2240 return false; 2241 } 2242 2243 /* 2244 * Treat the equal sign as a part of the attribute 2245 * name if it is the first encountered byte. 2246 * 2247 * @see https://html.spec.whatwg.org/multipage/parsing.html#before-attribute-name-state 2248 */ 2249 $name_length = '=' === $this->html[ $this->bytes_already_parsed ] 2250 ? 1 + strcspn( $this->html, "=/> \t\f\r\n", $this->bytes_already_parsed + 1 ) 2251 : strcspn( $this->html, "=/> \t\f\r\n", $this->bytes_already_parsed ); 2252 2253 // No attribute, just tag closer. 2254 if ( 0 === $name_length || $this->bytes_already_parsed + $name_length >= $doc_length ) { 2255 return false; 2256 } 2257 2258 $attribute_start = $this->bytes_already_parsed; 2259 $attribute_name = substr( $this->html, $attribute_start, $name_length ); 2260 $this->bytes_already_parsed += $name_length; 2261 if ( $this->bytes_already_parsed >= $doc_length ) { 2262 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 2263 2264 return false; 2265 } 2266 2267 $this->skip_whitespace(); 2268 if ( $this->bytes_already_parsed >= $doc_length ) { 2269 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 2270 2271 return false; 2272 } 2273 2274 $has_value = '=' === $this->html[ $this->bytes_already_parsed ]; 2275 if ( $has_value ) { 2276 ++$this->bytes_already_parsed; 2277 $this->skip_whitespace(); 2278 if ( $this->bytes_already_parsed >= $doc_length ) { 2279 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 2280 2281 return false; 2282 } 2283 2284 switch ( $this->html[ $this->bytes_already_parsed ] ) { 2285 case "'": 2286 case '"': 2287 $quote = $this->html[ $this->bytes_already_parsed ]; 2288 $value_start = $this->bytes_already_parsed + 1; 2289 $end_quote_at = strpos( $this->html, $quote, $value_start ); 2290 $end_quote_at = false === $end_quote_at ? $doc_length : $end_quote_at; 2291 $value_length = $end_quote_at - $value_start; 2292 $attribute_end = $end_quote_at + 1; 2293 $this->bytes_already_parsed = $attribute_end; 2294 break; 2295 2296 default: 2297 $value_start = $this->bytes_already_parsed; 2298 $value_length = strcspn( $this->html, "> \t\f\r\n", $value_start ); 2299 $attribute_end = $value_start + $value_length; 2300 $this->bytes_already_parsed = $attribute_end; 2301 } 2302 } else { 2303 $value_start = $this->bytes_already_parsed; 2304 $value_length = 0; 2305 $attribute_end = $attribute_start + $name_length; 2306 } 2307 2308 if ( $attribute_end >= $doc_length ) { 2309 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 2310 2311 return false; 2312 } 2313 2314 if ( $this->is_closing_tag ) { 2315 return true; 2316 } 2317 2318 /* 2319 * > There must never be two or more attributes on 2320 * > the same start tag whose names are an ASCII 2321 * > case-insensitive match for each other. 2322 * - HTML 5 spec 2323 * 2324 * @see https://html.spec.whatwg.org/multipage/syntax.html#attributes-2:ascii-case-insensitive 2325 * 2326 * The tokenizer replaces U+0000 NULL bytes in 2327 * attribute names with U+FFFD. 2328 * 2329 * @see https://html.spec.whatwg.org/#attribute-name-state 2330 */ 2331 $comparable_name = strtolower( str_replace( "\x00", "\u{FFFD}", $attribute_name ) ); 2332 2333 // If an attribute is listed many times, only use the first declaration and ignore the rest. 2334 if ( ! isset( $this->attributes[ $comparable_name ] ) ) { 2335 $this->attributes[ $comparable_name ] = new WP_HTML_Attribute_Token( 2336 $attribute_name, 2337 $value_start, 2338 $value_length, 2339 $attribute_start, 2340 $attribute_end - $attribute_start, 2341 ! $has_value 2342 ); 2343 2344 return true; 2345 } 2346 2347 /* 2348 * Track the duplicate attributes so if we remove it, all disappear together. 2349 * 2350 * While `$this->duplicated_attributes` could always be stored as an `array()`, 2351 * which would simplify the logic here, storing a `null` and only allocating 2352 * an array when encountering duplicates avoids needless allocations in the 2353 * normative case of parsing tags with no duplicate attributes. 2354 */ 2355 $duplicate_span = new WP_HTML_Span( $attribute_start, $attribute_end - $attribute_start ); 2356 if ( null === $this->duplicate_attributes ) { 2357 $this->duplicate_attributes = array( $comparable_name => array( $duplicate_span ) ); 2358 } elseif ( ! isset( $this->duplicate_attributes[ $comparable_name ] ) ) { 2359 $this->duplicate_attributes[ $comparable_name ] = array( $duplicate_span ); 2360 } else { 2361 $this->duplicate_attributes[ $comparable_name ][] = $duplicate_span; 2362 } 2363 2364 return true; 2365 } 2366 2367 /** 2368 * Move the internal cursor past any immediate successive whitespace. 2369 * 2370 * @since 6.2.0 2371 * @ignore 2372 */ 2373 private function skip_whitespace(): void { 2374 $this->bytes_already_parsed += strspn( $this->html, " \t\f\r\n", $this->bytes_already_parsed ); 2375 } 2376 2377 /** 2378 * Applies attribute updates and cleans up once a tag is fully parsed. 2379 * 2380 * @since 6.2.0 2381 * @ignore 2382 */ 2383 private function after_tag(): void { 2384 /* 2385 * There could be lexical updates enqueued for an attribute that 2386 * also exists on the next tag. In order to avoid conflating the 2387 * attributes across the two tags, lexical updates with names 2388 * need to be flushed to raw lexical updates. 2389 */ 2390 $this->class_name_updates_to_attributes_updates(); 2391 2392 /* 2393 * Purge updates if there are too many. The actual count isn't 2394 * scientific, but a few values from 100 to a few thousand were 2395 * tests to find a practically-useful limit. 2396 * 2397 * If the update queue grows too big, then the Tag Processor 2398 * will spend more time iterating through them and lose the 2399 * efficiency gains of deferring applying them. 2400 */ 2401 if ( 1000 < count( $this->lexical_updates ) ) { 2402 $this->get_updated_html(); 2403 } 2404 2405 foreach ( $this->lexical_updates as $name => $update ) { 2406 /* 2407 * Any updates appearing after the cursor should be applied 2408 * before proceeding, otherwise they may be overlooked. 2409 */ 2410 if ( $update->start >= $this->bytes_already_parsed ) { 2411 $this->get_updated_html(); 2412 break; 2413 } 2414 2415 if ( is_int( $name ) ) { 2416 continue; 2417 } 2418 2419 $this->lexical_updates[] = $update; 2420 unset( $this->lexical_updates[ $name ] ); 2421 } 2422 2423 $this->token_starts_at = null; 2424 $this->token_length = null; 2425 $this->has_self_closing_flag = false; 2426 $this->tag_name_starts_at = null; 2427 $this->tag_name_length = null; 2428 $this->text_starts_at = 0; 2429 $this->text_length = 0; 2430 $this->is_closing_tag = null; 2431 $this->attributes = array(); 2432 $this->comment_type = null; 2433 $this->text_node_classification = self::TEXT_IS_GENERIC; 2434 $this->duplicate_attributes = null; 2435 } 2436 2437 /** 2438 * Converts class name updates into tag attributes updates 2439 * (they are accumulated in different data formats for performance). 2440 * 2441 * @since 6.2.0 2442 * @ignore 2443 * 2444 * @see WP_HTML_Tag_Processor::$lexical_updates 2445 * @see WP_HTML_Tag_Processor::$classname_updates 2446 */ 2447 private function class_name_updates_to_attributes_updates(): void { 2448 if ( count( $this->classname_updates ) === 0 ) { 2449 return; 2450 } 2451 2452 $existing_class = $this->get_enqueued_attribute_value( 'class' ); 2453 if ( null === $existing_class || true === $existing_class ) { 2454 $existing_class = ''; 2455 } 2456 2457 if ( false === $existing_class && isset( $this->attributes['class'] ) ) { 2458 $existing_class = $this->get_decoded_attribute_value( $this->attributes['class'] ); 2459 } 2460 2461 if ( false === $existing_class ) { 2462 $existing_class = ''; 2463 } 2464 2465 /** 2466 * Updated "class" attribute value. 2467 * 2468 * This is incrementally built while scanning through the existing class 2469 * attribute, skipping removed classes on the way, and then appending 2470 * added classes at the end. Only when finished processing will the 2471 * value contain the final new value. 2472 2473 * @var string $class 2474 */ 2475 $class = ''; 2476 2477 /** 2478 * Tracks the cursor position in the existing 2479 * class attribute value while parsing. 2480 * 2481 * @var int $at 2482 */ 2483 $at = 0; 2484 2485 /** 2486 * Indicates if there's any need to modify the existing class attribute. 2487 * 2488 * If a call to `add_class()` and `remove_class()` wouldn't impact 2489 * the `class` attribute value then there's no need to rebuild it. 2490 * For example, when adding a class that's already present or 2491 * removing one that isn't. 2492 * 2493 * This flag enables a performance optimization when none of the enqueued 2494 * class updates would impact the `class` attribute; namely, that the 2495 * processor can continue without modifying the input document, as if 2496 * none of the `add_class()` or `remove_class()` calls had been made. 2497 * 2498 * This flag is set upon the first change that requires a string update. 2499 * 2500 * @var bool $modified 2501 */ 2502 $modified = false; 2503 2504 $seen = array(); 2505 $to_remove = array(); 2506 $is_quirks = self::QUIRKS_MODE === $this->compat_mode; 2507 if ( $is_quirks ) { 2508 foreach ( $this->classname_updates as $updated_name => $action ) { 2509 if ( self::REMOVE_CLASS === $action ) { 2510 $to_remove[] = strtolower( $updated_name ); 2511 } 2512 } 2513 } else { 2514 foreach ( $this->classname_updates as $updated_name => $action ) { 2515 if ( self::REMOVE_CLASS === $action ) { 2516 $to_remove[] = $updated_name; 2517 } 2518 } 2519 } 2520 2521 // Remove unwanted classes by only copying the new ones. 2522 $existing_class_length = strlen( $existing_class ); 2523 while ( $at < $existing_class_length ) { 2524 // Skip to the first non-whitespace character. 2525 $ws_at = $at; 2526 $ws_length = strspn( $existing_class, " \t\f\r\n", $ws_at ); 2527 $at += $ws_length; 2528 2529 // Capture the class name – it's everything until the next whitespace. 2530 $name_length = strcspn( $existing_class, " \t\f\r\n", $at ); 2531 if ( 0 === $name_length ) { 2532 // If no more class names are found then that's the end. 2533 break; 2534 } 2535 2536 $name = substr( $existing_class, $at, $name_length ); 2537 $comparable_class_name = $is_quirks ? strtolower( $name ) : $name; 2538 $at += $name_length; 2539 2540 // If this class is marked for removal, remove it and move on to the next one. 2541 if ( in_array( $comparable_class_name, $to_remove, true ) ) { 2542 $modified = true; 2543 continue; 2544 } 2545 2546 // If a class has already been seen then skip it; it should not be added twice. 2547 if ( in_array( $comparable_class_name, $seen, true ) ) { 2548 continue; 2549 } 2550 2551 $seen[] = $comparable_class_name; 2552 2553 /* 2554 * Otherwise, append it to the new "class" attribute value. 2555 * 2556 * There are options for handling whitespace between tags. 2557 * Preserving the existing whitespace produces fewer changes 2558 * to the HTML content and should clarify the before/after 2559 * content when debugging the modified output. 2560 * 2561 * This approach contrasts normalizing the inter-class 2562 * whitespace to a single space, which might appear cleaner 2563 * in the output HTML but produce a noisier change. 2564 */ 2565 if ( '' !== $class ) { 2566 $class .= substr( $existing_class, $ws_at, $ws_length ); 2567 } 2568 $class .= $name; 2569 } 2570 2571 // Add new classes by appending those which haven't already been seen. 2572 foreach ( $this->classname_updates as $name => $operation ) { 2573 $comparable_name = $is_quirks ? strtolower( $name ) : $name; 2574 if ( self::ADD_CLASS === $operation && ! in_array( $comparable_name, $seen, true ) ) { 2575 $modified = true; 2576 2577 $class .= strlen( $class ) > 0 ? ' ' : ''; 2578 $class .= $name; 2579 } 2580 } 2581 2582 $this->classname_updates = array(); 2583 if ( ! $modified ) { 2584 return; 2585 } 2586 2587 if ( strlen( $class ) > 0 ) { 2588 $this->set_attribute( 'class', $class ); 2589 } else { 2590 $this->remove_attribute( 'class' ); 2591 } 2592 } 2593 2594 /** 2595 * Applies attribute updates to HTML document. 2596 * 2597 * @since 6.2.0 2598 * @since 6.2.1 Accumulates shift for internal cursor and passed pointer. 2599 * @since 6.3.0 Invalidate any bookmarks whose targets are overwritten. 2600 * @ignore 2601 * 2602 * @param int $shift_this_point Accumulate and return shift for this position. 2603 * @return int How many bytes the given pointer moved in response to the updates. 2604 */ 2605 private function apply_attributes_updates( int $shift_this_point ): int { 2606 if ( ! count( $this->lexical_updates ) ) { 2607 return 0; 2608 } 2609 2610 $accumulated_shift_for_given_point = 0; 2611 2612 /* 2613 * Attribute updates can be enqueued in any order but updates 2614 * to the document must occur in lexical order; that is, each 2615 * replacement must be made before all others which follow it 2616 * at later string indices in the input document. 2617 * 2618 * Sorting avoids making out-of-order replacements which 2619 * can lead to mangled output, partially-duplicated 2620 * attributes, and overwritten attributes. 2621 */ 2622 usort( $this->lexical_updates, array( self::class, 'sort_start_ascending' ) ); 2623 2624 $bytes_already_copied = 0; 2625 $output_buffer = ''; 2626 foreach ( $this->lexical_updates as $diff ) { 2627 $shift = strlen( $diff->text ) - $diff->length; 2628 2629 // Adjust the cursor position by however much an update affects it. 2630 if ( $diff->start < $this->bytes_already_parsed ) { 2631 $this->bytes_already_parsed += $shift; 2632 } 2633 2634 // Accumulate shift of the given pointer within this function call. 2635 if ( $diff->start < $shift_this_point ) { 2636 $accumulated_shift_for_given_point += $shift; 2637 } 2638 2639 $output_buffer .= substr( $this->html, $bytes_already_copied, $diff->start - $bytes_already_copied ); 2640 $output_buffer .= $diff->text; 2641 $bytes_already_copied = $diff->start + $diff->length; 2642 } 2643 2644 $this->html = $output_buffer . substr( $this->html, $bytes_already_copied ); 2645 2646 /* 2647 * Adjust bookmark locations to account for how the text 2648 * replacements adjust offsets in the input document. 2649 */ 2650 foreach ( $this->bookmarks as $bookmark_name => $bookmark ) { 2651 $bookmark_end = $bookmark->start + $bookmark->length; 2652 2653 /* 2654 * Each lexical update which appears before the bookmark's endpoints 2655 * might shift the offsets for those endpoints. Loop through each change 2656 * and accumulate the total shift for each bookmark, then apply that 2657 * shift after tallying the full delta. 2658 */ 2659 $head_delta = 0; 2660 $tail_delta = 0; 2661 2662 foreach ( $this->lexical_updates as $diff ) { 2663 $diff_end = $diff->start + $diff->length; 2664 2665 if ( $bookmark->start < $diff->start && $bookmark_end < $diff->start ) { 2666 break; 2667 } 2668 2669 if ( $bookmark->start >= $diff->start && $bookmark_end < $diff_end ) { 2670 $this->release_bookmark( $bookmark_name ); 2671 continue 2; 2672 } 2673 2674 $delta = strlen( $diff->text ) - $diff->length; 2675 2676 if ( $bookmark->start >= $diff->start ) { 2677 $head_delta += $delta; 2678 } 2679 2680 if ( $bookmark_end >= $diff_end ) { 2681 $tail_delta += $delta; 2682 } 2683 } 2684 2685 $bookmark->start += $head_delta; 2686 $bookmark->length += $tail_delta - $head_delta; 2687 } 2688 2689 $this->lexical_updates = array(); 2690 2691 return $accumulated_shift_for_given_point; 2692 } 2693 2694 /** 2695 * Checks whether a bookmark with the given name exists. 2696 * 2697 * @since 6.3.0 2698 * 2699 * @param string $bookmark_name Name to identify a bookmark that potentially exists. 2700 * @return bool Whether that bookmark exists. 2701 */ 2702 public function has_bookmark( $bookmark_name ): bool { 2703 return array_key_exists( $bookmark_name, $this->bookmarks ); 2704 } 2705 2706 /** 2707 * Move the internal cursor in the Tag Processor to a given bookmark's location. 2708 * 2709 * In order to prevent accidental infinite loops, there's a 2710 * maximum limit on the number of times seek() can be called. 2711 * 2712 * @since 6.2.0 2713 * 2714 * @param string $bookmark_name Jump to the place in the document identified by this bookmark name. 2715 * @return bool Whether the internal cursor was successfully moved to the bookmark's location. 2716 */ 2717 public function seek( $bookmark_name ): bool { 2718 if ( ! array_key_exists( $bookmark_name, $this->bookmarks ) ) { 2719 _doing_it_wrong( 2720 __METHOD__, 2721 __( 'Unknown bookmark name.' ), 2722 '6.2.0' 2723 ); 2724 return false; 2725 } 2726 2727 $existing_bookmark = $this->bookmarks[ $bookmark_name ]; 2728 2729 if ( 2730 $this->token_starts_at === $existing_bookmark->start && 2731 $this->token_length === $existing_bookmark->length 2732 ) { 2733 return true; 2734 } 2735 2736 if ( ++$this->seek_count > static::MAX_SEEK_OPS ) { 2737 _doing_it_wrong( 2738 __METHOD__, 2739 __( 'Too many calls to seek() - this can lead to performance issues.' ), 2740 '6.2.0' 2741 ); 2742 return false; 2743 } 2744 2745 // Flush out any pending updates to the document. 2746 $this->get_updated_html(); 2747 2748 // Point this tag processor before the sought tag opener and consume it. 2749 $this->bytes_already_parsed = $this->bookmarks[ $bookmark_name ]->start; 2750 $this->parser_state = self::STATE_READY; 2751 return $this->next_token(); 2752 } 2753 2754 /** 2755 * Compare two WP_HTML_Text_Replacement objects. 2756 * 2757 * @since 6.2.0 2758 * @ignore 2759 * 2760 * @param WP_HTML_Text_Replacement $a First attribute update. 2761 * @param WP_HTML_Text_Replacement $b Second attribute update. 2762 * @return int Comparison value for string order. 2763 */ 2764 private static function sort_start_ascending( WP_HTML_Text_Replacement $a, WP_HTML_Text_Replacement $b ): int { 2765 $by_start = $a->start - $b->start; 2766 if ( 0 !== $by_start ) { 2767 return $by_start; 2768 } 2769 2770 $by_text = isset( $a->text, $b->text ) ? strcmp( $a->text, $b->text ) : 0; 2771 if ( 0 !== $by_text ) { 2772 return $by_text; 2773 } 2774 2775 /* 2776 * This code should be unreachable, because it implies the two replacements 2777 * start at the same location and contain the same text. 2778 */ 2779 return $a->length - $b->length; 2780 } 2781 2782 /** 2783 * Return the enqueued value for a given attribute, if one exists. 2784 * 2785 * Enqueued updates can take different data types: 2786 * - If an update is enqueued and is boolean, the return will be `true` 2787 * - If an update is otherwise enqueued, the return will be the string value of that update. 2788 * - If an attribute is enqueued to be removed, the return will be `null` to indicate that. 2789 * - If no updates are enqueued, the return will be `false` to differentiate from "removed." 2790 * 2791 * @since 6.2.0 2792 * @ignore 2793 * 2794 * @param string $comparable_name The attribute name in its comparable form. 2795 * @return string|bool|null Value of enqueued update if present, otherwise false. 2796 */ 2797 private function get_enqueued_attribute_value( string $comparable_name ) { 2798 if ( self::STATE_MATCHED_TAG !== $this->parser_state ) { 2799 return false; 2800 } 2801 2802 if ( ! isset( $this->lexical_updates[ $comparable_name ] ) ) { 2803 return false; 2804 } 2805 2806 $enqueued_text = $this->lexical_updates[ $comparable_name ]->text; 2807 2808 // Removed attributes erase the entire span. 2809 if ( '' === $enqueued_text ) { 2810 return null; 2811 } 2812 2813 /* 2814 * Boolean attribute updates are just the attribute name without a corresponding value. 2815 * 2816 * This value might differ from the given comparable name in that there could be leading 2817 * or trailing whitespace, and that the casing follows the name given in `set_attribute`. 2818 * 2819 * Example: 2820 * 2821 * $p->set_attribute( 'data-TEST-id', 'update' ); 2822 * 'update' === $p->get_enqueued_attribute_value( 'data-test-id' ); 2823 * 2824 * Detect this difference based on the absence of the `=`, which _must_ exist in any 2825 * attribute containing a value, e.g. `<input type="text" enabled />`. 2826 * ¹ ² 2827 * 1. Attribute with a string value. 2828 * 2. Boolean attribute whose value is `true`. 2829 */ 2830 $equals_at = strpos( $enqueued_text, '=' ); 2831 if ( false === $equals_at ) { 2832 return true; 2833 } 2834 2835 /* 2836 * Finally, a normal update's value will appear after the `=` and 2837 * be double-quoted, as performed incidentally by `set_attribute`. 2838 * 2839 * e.g. `type="text"` 2840 * ¹² ³ 2841 * 1. Equals is here. 2842 * 2. Double-quoting starts one after the equals sign. 2843 * 3. Double-quoting ends at the last character in the update. 2844 */ 2845 $enqueued_value = substr( $enqueued_text, $equals_at + 2, -1 ); 2846 return WP_HTML_Decoder::decode_attribute( $enqueued_value ); 2847 } 2848 2849 /** 2850 * Returns the value of a requested attribute from a matched tag opener if that attribute exists. 2851 * 2852 * Example: 2853 * 2854 * $p = new WP_HTML_Tag_Processor( '<div enabled class="test" data-test-id="14">Test</div>' ); 2855 * $p->next_tag( array( 'class_name' => 'test' ) ) === true; 2856 * $p->get_attribute( 'data-test-id' ) === '14'; 2857 * $p->get_attribute( 'enabled' ) === true; 2858 * $p->get_attribute( 'aria-label' ) === null; 2859 * 2860 * $p->next_tag() === false; 2861 * $p->get_attribute( 'class' ) === null; 2862 * 2863 * @since 6.2.0 2864 * 2865 * @param string $name Name of attribute whose value is requested. 2866 * @return string|true|null Value of attribute or `null` if not available. Boolean attributes return `true`. 2867 */ 2868 public function get_attribute( $name ) { 2869 if ( self::STATE_MATCHED_TAG !== $this->parser_state ) { 2870 return null; 2871 } 2872 2873 $comparable = strtolower( $name ); 2874 2875 /* 2876 * For every attribute other than `class` it's possible to perform a quick check if 2877 * there's an enqueued lexical update whose value takes priority over what's found in 2878 * the input document. 2879 * 2880 * The `class` attribute is special though because of the exposed helpers `add_class` 2881 * and `remove_class`. These form a builder for the `class` attribute, so an additional 2882 * check for enqueued class changes is required in addition to the check for any enqueued 2883 * attribute values. If any exist, those enqueued class changes must first be flushed out 2884 * into an attribute value update. 2885 */ 2886 if ( 'class' === $comparable ) { 2887 $this->class_name_updates_to_attributes_updates(); 2888 } 2889 2890 // Return any enqueued attribute value updates if they exist. 2891 $enqueued_value = $this->get_enqueued_attribute_value( $comparable ); 2892 if ( false !== $enqueued_value ) { 2893 return $enqueued_value; 2894 } 2895 2896 if ( ! isset( $this->attributes[ $comparable ] ) ) { 2897 return null; 2898 } 2899 2900 $attribute = $this->attributes[ $comparable ]; 2901 2902 /* 2903 * This flag distinguishes an attribute with no value 2904 * from an attribute with an empty string value. For 2905 * unquoted attributes this could look very similar. 2906 * It refers to whether an `=` follows the name. 2907 * 2908 * e.g. <div boolean-attribute empty-attribute=></div> 2909 * ¹ ² 2910 * 1. Attribute `boolean-attribute` is `true`. 2911 * 2. Attribute `empty-attribute` is `""`. 2912 */ 2913 if ( true === $attribute->is_true ) { 2914 return true; 2915 } 2916 2917 return $this->get_decoded_attribute_value( $attribute ); 2918 } 2919 2920 /** 2921 * Decode an attribute value from source. 2922 * 2923 * This method applies the following transformations that the processor defers: 2924 * - Normalize newlines (input stream preprocessing) 2925 * - Replace NULL bytes (tokenization) 2926 * - Decode character references (tokenization) 2927 * 2928 * @since 7.1.0 2929 * @ignore 2930 * 2931 * @param WP_HTML_Attribute_Token $attribute Attribute token from the input document. 2932 * @return string Decoded attribute value. 2933 */ 2934 private function get_decoded_attribute_value( WP_HTML_Attribute_Token $attribute ): string { 2935 $raw_value = substr( $this->html, $attribute->value_starts_at, $attribute->value_length ); 2936 $raw_value = str_replace( "\r\n", "\n", $raw_value ); 2937 $raw_value = str_replace( "\r", "\n", $raw_value ); 2938 $raw_value = str_replace( "\x00", "\u{FFFD}", $raw_value ); 2939 return WP_HTML_Decoder::decode_attribute( $raw_value ); 2940 } 2941 2942 /** 2943 * Gets lowercase names of all attributes matching a given prefix in the current tag. 2944 * 2945 * Note that matching is case-insensitive. This is in accordance with the spec: 2946 * 2947 * > There must never be two or more attributes on 2948 * > the same start tag whose names are an ASCII 2949 * > case-insensitive match for each other. 2950 * - HTML 5 spec 2951 * 2952 * Example: 2953 * 2954 * $p = new WP_HTML_Tag_Processor( '<div data-ENABLED class="test" DATA-test-id="14">Test</div>' ); 2955 * $p->next_tag( array( 'class_name' => 'test' ) ) === true; 2956 * $p->get_attribute_names_with_prefix( 'data-' ) === array( 'data-enabled', 'data-test-id' ); 2957 * 2958 * $p->next_tag() === false; 2959 * $p->get_attribute_names_with_prefix( 'data-' ) === null; 2960 * 2961 * @since 6.2.0 2962 * 2963 * @see https://html.spec.whatwg.org/multipage/syntax.html#attributes-2:ascii-case-insensitive 2964 * 2965 * @param string $prefix Prefix of requested attribute names. 2966 * @return array|null List of attribute names, or `null` when no tag opener is matched. 2967 * @phpstan-return list<non-empty-string>|null 2968 */ 2969 public function get_attribute_names_with_prefix( $prefix ): ?array { 2970 if ( 2971 self::STATE_MATCHED_TAG !== $this->parser_state || 2972 $this->is_closing_tag 2973 ) { 2974 return null; 2975 } 2976 2977 $comparable = strtolower( $prefix ); 2978 2979 /* 2980 * For the `class` attribute, ensure that enqueued class changes from 2981 * `add_class` and `remove_class` are flushed into attribute updates. 2982 */ 2983 $has_class = isset( $this->attributes['class'] ); 2984 if ( '' === $comparable || str_starts_with( 'class', $comparable ) ) { 2985 foreach ( $this->classname_updates as $update ) { 2986 if ( 2987 ( $has_class && self::REMOVE_CLASS === $update ) || 2988 ( ! $has_class && self::ADD_CLASS === $update ) 2989 ) { 2990 $this->class_name_updates_to_attributes_updates(); 2991 break; 2992 } 2993 } 2994 } 2995 2996 $additions = array(); 2997 $removals = array(); 2998 foreach ( $this->lexical_updates as $update_name => $update ) { 2999 if ( is_int( $update_name ) || 'modifiable text' === $update_name ) { 3000 continue; 3001 } 3002 3003 if ( '' === $update->text ) { 3004 $removals[ $update_name ] = true; 3005 } elseif ( ! isset( $this->attributes[ $update_name ] ) && str_starts_with( $update_name, $comparable ) ) { 3006 $additions[] = $update_name; 3007 } 3008 } 3009 3010 $matches = array(); 3011 foreach ( array_keys( $this->attributes ) as $attr_name ) { 3012 if ( str_starts_with( $attr_name, $comparable ) && ! isset( $removals[ $attr_name ] ) ) { 3013 $matches[] = $attr_name; 3014 } 3015 } 3016 3017 return empty( $additions ) ? $matches : array_merge( $additions, $matches ); 3018 } 3019 3020 /** 3021 * Returns the namespace of the matched token. 3022 * 3023 * @since 6.7.0 3024 * 3025 * @return string One of 'html', 'math', or 'svg'. 3026 */ 3027 public function get_namespace(): string { 3028 return $this->parsing_namespace; 3029 } 3030 3031 /** 3032 * Returns the uppercase name of the matched tag. 3033 * 3034 * Example: 3035 * 3036 * $p = new WP_HTML_Tag_Processor( '<div class="test">Test</div>' ); 3037 * $p->next_tag() === true; 3038 * $p->get_tag() === 'DIV'; 3039 * 3040 * $p->next_tag() === false; 3041 * $p->get_tag() === null; 3042 * 3043 * @since 6.2.0 3044 * 3045 * @return string|null Name of currently matched tag in input HTML, or `null` if none found. 3046 */ 3047 public function get_tag(): ?string { 3048 if ( null === $this->tag_name_starts_at ) { 3049 return null; 3050 } 3051 3052 $tag_name = str_replace( "\x00", "\u{FFFD}", substr( $this->html, $this->tag_name_starts_at, $this->tag_name_length ) ); 3053 3054 if ( self::STATE_MATCHED_TAG === $this->parser_state ) { 3055 return strtoupper( $tag_name ); 3056 } 3057 3058 /* 3059 * Processing instruction targets are case-sensitive 3060 * and returned as they appear in the input HTML. 3061 */ 3062 if ( self::STATE_PROCESSING_INSTRUCTION === $this->parser_state ) { 3063 return $tag_name; 3064 } 3065 3066 if ( 3067 self::STATE_COMMENT === $this->parser_state && 3068 self::COMMENT_AS_PI_NODE_LOOKALIKE === $this->get_comment_type() 3069 ) { 3070 return $tag_name; 3071 } 3072 3073 return null; 3074 } 3075 3076 /** 3077 * Returns the adjusted tag name for a given token, taking into 3078 * account the current parsing context, whether HTML, SVG, or MathML. 3079 * 3080 * @since 6.7.0 3081 * 3082 * @return string|null Name of current tag name. 3083 */ 3084 public function get_qualified_tag_name(): ?string { 3085 $tag_name = $this->get_tag(); 3086 if ( null === $tag_name ) { 3087 return null; 3088 } 3089 3090 if ( 'html' === $this->get_namespace() ) { 3091 return $tag_name; 3092 } 3093 3094 $lower_tag_name = strtolower( $tag_name ); 3095 if ( 'math' === $this->get_namespace() ) { 3096 return $lower_tag_name; 3097 } 3098 3099 if ( 'svg' === $this->get_namespace() ) { 3100 switch ( $lower_tag_name ) { 3101 case 'altglyph': 3102 return 'altGlyph'; 3103 3104 case 'altglyphdef': 3105 return 'altGlyphDef'; 3106 3107 case 'altglyphitem': 3108 return 'altGlyphItem'; 3109 3110 case 'animatecolor': 3111 return 'animateColor'; 3112 3113 case 'animatemotion': 3114 return 'animateMotion'; 3115 3116 case 'animatetransform': 3117 return 'animateTransform'; 3118 3119 case 'clippath': 3120 return 'clipPath'; 3121 3122 case 'feblend': 3123 return 'feBlend'; 3124 3125 case 'fecolormatrix': 3126 return 'feColorMatrix'; 3127 3128 case 'fecomponenttransfer': 3129 return 'feComponentTransfer'; 3130 3131 case 'fecomposite': 3132 return 'feComposite'; 3133 3134 case 'feconvolvematrix': 3135 return 'feConvolveMatrix'; 3136 3137 case 'fediffuselighting': 3138 return 'feDiffuseLighting'; 3139 3140 case 'fedisplacementmap': 3141 return 'feDisplacementMap'; 3142 3143 case 'fedistantlight': 3144 return 'feDistantLight'; 3145 3146 case 'fedropshadow': 3147 return 'feDropShadow'; 3148 3149 case 'feflood': 3150 return 'feFlood'; 3151 3152 case 'fefunca': 3153 return 'feFuncA'; 3154 3155 case 'fefuncb': 3156 return 'feFuncB'; 3157 3158 case 'fefuncg': 3159 return 'feFuncG'; 3160 3161 case 'fefuncr': 3162 return 'feFuncR'; 3163 3164 case 'fegaussianblur': 3165 return 'feGaussianBlur'; 3166 3167 case 'feimage': 3168 return 'feImage'; 3169 3170 case 'femerge': 3171 return 'feMerge'; 3172 3173 case 'femergenode': 3174 return 'feMergeNode'; 3175 3176 case 'femorphology': 3177 return 'feMorphology'; 3178 3179 case 'feoffset': 3180 return 'feOffset'; 3181 3182 case 'fepointlight': 3183 return 'fePointLight'; 3184 3185 case 'fespecularlighting': 3186 return 'feSpecularLighting'; 3187 3188 case 'fespotlight': 3189 return 'feSpotLight'; 3190 3191 case 'fetile': 3192 return 'feTile'; 3193 3194 case 'feturbulence': 3195 return 'feTurbulence'; 3196 3197 case 'foreignobject': 3198 return 'foreignObject'; 3199 3200 case 'glyphref': 3201 return 'glyphRef'; 3202 3203 case 'lineargradient': 3204 return 'linearGradient'; 3205 3206 case 'radialgradient': 3207 return 'radialGradient'; 3208 3209 case 'textpath': 3210 return 'textPath'; 3211 3212 default: 3213 return $lower_tag_name; 3214 } 3215 } 3216 3217 // This unnecessary return prevents tools from inaccurately reporting type errors. 3218 return $tag_name; 3219 } 3220 3221 /** 3222 * Returns the adjusted attribute name for a given attribute, taking into 3223 * account the current parsing context, whether HTML, SVG, or MathML. 3224 * 3225 * In SVG and MathML contexts, adjusted foreign attributes with a namespace 3226 * prefix use a space between the prefix and local name. For example, 3227 * `xlink:href` is returned as `xlink href`, while the unprefixed `xmlns` 3228 * attribute is returned as `xmlns`. Non-adjusted attributes with a colon in 3229 * their name, such as `foo:bar`, are returned unchanged. 3230 * 3231 * @since 6.7.0 3232 * 3233 * @param string $attribute_name Which attribute to adjust. 3234 * @return string|null 3235 */ 3236 public function get_qualified_attribute_name( $attribute_name ): ?string { 3237 if ( self::STATE_MATCHED_TAG !== $this->parser_state ) { 3238 return null; 3239 } 3240 3241 $namespace = $this->get_namespace(); 3242 $lower_name = strtolower( $attribute_name ); 3243 3244 if ( 'math' === $namespace && 'definitionurl' === $lower_name ) { 3245 return 'definitionURL'; 3246 } 3247 3248 if ( 'svg' === $this->get_namespace() ) { 3249 switch ( $lower_name ) { 3250 case 'attributename': 3251 return 'attributeName'; 3252 3253 case 'attributetype': 3254 return 'attributeType'; 3255 3256 case 'basefrequency': 3257 return 'baseFrequency'; 3258 3259 case 'baseprofile': 3260 return 'baseProfile'; 3261 3262 case 'calcmode': 3263 return 'calcMode'; 3264 3265 case 'clippathunits': 3266 return 'clipPathUnits'; 3267 3268 case 'diffuseconstant': 3269 return 'diffuseConstant'; 3270 3271 case 'edgemode': 3272 return 'edgeMode'; 3273 3274 case 'filterunits': 3275 return 'filterUnits'; 3276 3277 case 'glyphref': 3278 return 'glyphRef'; 3279 3280 case 'gradienttransform': 3281 return 'gradientTransform'; 3282 3283 case 'gradientunits': 3284 return 'gradientUnits'; 3285 3286 case 'kernelmatrix': 3287 return 'kernelMatrix'; 3288 3289 case 'kernelunitlength': 3290 return 'kernelUnitLength'; 3291 3292 case 'keypoints': 3293 return 'keyPoints'; 3294 3295 case 'keysplines': 3296 return 'keySplines'; 3297 3298 case 'keytimes': 3299 return 'keyTimes'; 3300 3301 case 'lengthadjust': 3302 return 'lengthAdjust'; 3303 3304 case 'limitingconeangle': 3305 return 'limitingConeAngle'; 3306 3307 case 'markerheight': 3308 return 'markerHeight'; 3309 3310 case 'markerunits': 3311 return 'markerUnits'; 3312 3313 case 'markerwidth': 3314 return 'markerWidth'; 3315 3316 case 'maskcontentunits': 3317 return 'maskContentUnits'; 3318 3319 case 'maskunits': 3320 return 'maskUnits'; 3321 3322 case 'numoctaves': 3323 return 'numOctaves'; 3324 3325 case 'pathlength': 3326 return 'pathLength'; 3327 3328 case 'patterncontentunits': 3329 return 'patternContentUnits'; 3330 3331 case 'patterntransform': 3332 return 'patternTransform'; 3333 3334 case 'patternunits': 3335 return 'patternUnits'; 3336 3337 case 'pointsatx': 3338 return 'pointsAtX'; 3339 3340 case 'pointsaty': 3341 return 'pointsAtY'; 3342 3343 case 'pointsatz': 3344 return 'pointsAtZ'; 3345 3346 case 'preservealpha': 3347 return 'preserveAlpha'; 3348 3349 case 'preserveaspectratio': 3350 return 'preserveAspectRatio'; 3351 3352 case 'primitiveunits': 3353 return 'primitiveUnits'; 3354 3355 case 'refx': 3356 return 'refX'; 3357 3358 case 'refy': 3359 return 'refY'; 3360 3361 case 'repeatcount': 3362 return 'repeatCount'; 3363 3364 case 'repeatdur': 3365 return 'repeatDur'; 3366 3367 case 'requiredextensions': 3368 return 'requiredExtensions'; 3369 3370 case 'requiredfeatures': 3371 return 'requiredFeatures'; 3372 3373 case 'specularconstant': 3374 return 'specularConstant'; 3375 3376 case 'specularexponent': 3377 return 'specularExponent'; 3378 3379 case 'spreadmethod': 3380 return 'spreadMethod'; 3381 3382 case 'startoffset': 3383 return 'startOffset'; 3384 3385 case 'stddeviation': 3386 return 'stdDeviation'; 3387 3388 case 'stitchtiles': 3389 return 'stitchTiles'; 3390 3391 case 'surfacescale': 3392 return 'surfaceScale'; 3393 3394 case 'systemlanguage': 3395 return 'systemLanguage'; 3396 3397 case 'tablevalues': 3398 return 'tableValues'; 3399 3400 case 'targetx': 3401 return 'targetX'; 3402 3403 case 'targety': 3404 return 'targetY'; 3405 3406 case 'textlength': 3407 return 'textLength'; 3408 3409 case 'viewbox': 3410 return 'viewBox'; 3411 3412 case 'viewtarget': 3413 return 'viewTarget'; 3414 3415 case 'xchannelselector': 3416 return 'xChannelSelector'; 3417 3418 case 'ychannelselector': 3419 return 'yChannelSelector'; 3420 3421 case 'zoomandpan': 3422 return 'zoomAndPan'; 3423 } 3424 } 3425 3426 if ( 'html' !== $namespace ) { 3427 switch ( $lower_name ) { 3428 case 'xlink:actuate': 3429 return 'xlink actuate'; 3430 3431 case 'xlink:arcrole': 3432 return 'xlink arcrole'; 3433 3434 case 'xlink:href': 3435 return 'xlink href'; 3436 3437 case 'xlink:role': 3438 return 'xlink role'; 3439 3440 case 'xlink:show': 3441 return 'xlink show'; 3442 3443 case 'xlink:title': 3444 return 'xlink title'; 3445 3446 case 'xlink:type': 3447 return 'xlink type'; 3448 3449 case 'xml:lang': 3450 return 'xml lang'; 3451 3452 case 'xml:space': 3453 return 'xml space'; 3454 3455 case 'xmlns': 3456 return 'xmlns'; 3457 3458 case 'xmlns:xlink': 3459 return 'xmlns xlink'; 3460 } 3461 } 3462 3463 return $attribute_name; 3464 } 3465 3466 /** 3467 * Indicates if the currently matched tag contains the self-closing flag. 3468 * 3469 * No HTML elements ought to have the self-closing flag and for those, the self-closing 3470 * flag will be ignored. For void elements this is benign because they "self close" 3471 * automatically. For non-void HTML elements though problems will appear if someone 3472 * intends to use a self-closing element in place of that element with an empty body. 3473 * For HTML foreign elements and custom elements the self-closing flag determines if 3474 * they self-close or not. 3475 * 3476 * This function does not determine if a tag is self-closing, 3477 * but only if the self-closing flag is present in the syntax. 3478 * 3479 * @since 6.3.0 3480 * 3481 * @return bool Whether the currently matched tag contains the self-closing flag. 3482 */ 3483 public function has_self_closing_flag(): bool { 3484 if ( self::STATE_MATCHED_TAG !== $this->parser_state ) { 3485 return false; 3486 } 3487 3488 return $this->has_self_closing_flag; 3489 } 3490 3491 /** 3492 * Indicates if the current tag token is a tag closer. 3493 * 3494 * Example: 3495 * 3496 * $p = new WP_HTML_Tag_Processor( '<div></div>' ); 3497 * $p->next_tag( array( 'tag_name' => 'div', 'tag_closers' => 'visit' ) ); 3498 * $p->is_tag_closer() === false; 3499 * 3500 * $p->next_tag( array( 'tag_name' => 'div', 'tag_closers' => 'visit' ) ); 3501 * $p->is_tag_closer() === true; 3502 * 3503 * @since 6.2.0 3504 * @since 6.7.0 Reports all BR tags as opening tags. 3505 * 3506 * @return bool Whether the current tag is a tag closer. 3507 */ 3508 public function is_tag_closer(): bool { 3509 return ( 3510 self::STATE_MATCHED_TAG === $this->parser_state && 3511 $this->is_closing_tag && 3512 3513 /* 3514 * The BR tag can only exist as an opening tag. If something like `</br>` 3515 * appears then the HTML parser will treat it as an opening tag with no 3516 * attributes. The BR tag is unique in this way. 3517 * 3518 * @see https://html.spec.whatwg.org/#parsing-main-inbody 3519 */ 3520 'BR' !== $this->get_tag() 3521 ); 3522 } 3523 3524 /** 3525 * Indicates the kind of matched token, if any. 3526 * 3527 * This differs from `get_token_name()` in that it always 3528 * returns a static string indicating the type, whereas 3529 * `get_token_name()` may return values derived from the 3530 * token itself, such as a tag name or processing 3531 * instruction tag. 3532 * 3533 * Possible values: 3534 * - `#tag` when matched on a tag. 3535 * - `#text` when matched on a text node. 3536 * - `#cdata-section` when matched on a CDATA node. 3537 * - `#comment` when matched on a comment. 3538 * - `#doctype` when matched on a DOCTYPE declaration. 3539 * - `#presumptuous-tag` when matched on an empty tag closer. 3540 * - `#funky-comment` when matched on a funky comment. 3541 * - `#processing-instruction` when matched on a processing instruction. 3542 * 3543 * @since 6.5.0 3544 * @since 7.1.0 Recognizes processing instructions. 3545 * 3546 * @return string|null What kind of token is matched, or null. 3547 * @phpstan-return '#tag'|'#text'|'#cdata-section'|'#comment'|'#doctype'|'#presumptuous-tag'|'#funky-comment'|'#processing-instruction'|null 3548 */ 3549 public function get_token_type(): ?string { 3550 switch ( $this->parser_state ) { 3551 case self::STATE_MATCHED_TAG: 3552 return '#tag'; 3553 3554 case self::STATE_DOCTYPE: 3555 return '#doctype'; 3556 3557 default: 3558 return $this->get_token_name(); 3559 } 3560 } 3561 3562 /** 3563 * Returns the node name represented by the token. 3564 * 3565 * This matches the DOM API value `nodeName`. Some values 3566 * are static, such as `#text` for a text node, while others 3567 * are dynamically generated from the token itself. 3568 * 3569 * Dynamic names: 3570 * - Uppercase tag name for tag matches. 3571 * - `html` for DOCTYPE declarations. 3572 * 3573 * Note that if the Tag Processor is not matched on a token 3574 * then this function will return `null`, either because it 3575 * hasn't yet found a token or because it reached the end 3576 * of the document without matching a token. 3577 * 3578 * @since 6.5.0 3579 * 3580 * @return string|null Name of the matched token. 3581 */ 3582 public function get_token_name(): ?string { 3583 switch ( $this->parser_state ) { 3584 case self::STATE_MATCHED_TAG: 3585 return $this->get_tag(); 3586 3587 case self::STATE_TEXT_NODE: 3588 return '#text'; 3589 3590 case self::STATE_CDATA_NODE: 3591 return '#cdata-section'; 3592 3593 case self::STATE_COMMENT: 3594 return '#comment'; 3595 3596 case self::STATE_DOCTYPE: 3597 return 'html'; 3598 3599 case self::STATE_PRESUMPTUOUS_TAG: 3600 return '#presumptuous-tag'; 3601 3602 case self::STATE_FUNKY_COMMENT: 3603 return '#funky-comment'; 3604 3605 case self::STATE_PROCESSING_INSTRUCTION: 3606 return '#processing-instruction'; 3607 } 3608 3609 return null; 3610 } 3611 3612 /** 3613 * Indicates what kind of comment produced the comment node. 3614 * 3615 * Because there are different kinds of HTML syntax which produce 3616 * comments, the Tag Processor tracks and exposes this as a type 3617 * for the comment. Nominally only regular HTML comments exist as 3618 * they are commonly known, but a number of unrelated syntax errors 3619 * also produce comments. 3620 * 3621 * @see self::COMMENT_AS_ABRUPTLY_CLOSED_COMMENT 3622 * @see self::COMMENT_AS_CDATA_LOOKALIKE 3623 * @see self::COMMENT_AS_INVALID_HTML 3624 * @see self::COMMENT_AS_HTML_COMMENT 3625 * @see self::COMMENT_AS_PI_NODE_LOOKALIKE 3626 * 3627 * @since 6.5.0 3628 * 3629 * @return string|null 3630 */ 3631 public function get_comment_type(): ?string { 3632 if ( self::STATE_COMMENT !== $this->parser_state ) { 3633 return null; 3634 } 3635 3636 return $this->comment_type; 3637 } 3638 3639 /** 3640 * Returns the text of a matched comment or null if not on a comment type node. 3641 * 3642 * This method returns the entire text content of a comment node as it 3643 * would appear in the browser. 3644 * 3645 * This differs from {@see ::get_modifiable_text()} in that certain comment 3646 * types in the HTML API cannot allow their entire comment text content to 3647 * be modified. Namely, "bogus comments" of the form `<?xml not allowed in html>` 3648 * will create a comment whose text content starts with `?`. Note that if 3649 * that character were modified, it would be possible to change the node 3650 * type. 3651 * 3652 * @since 6.7.0 3653 * 3654 * @return string|null The comment text as it would appear in the browser or null 3655 * if not on a comment type node. 3656 */ 3657 public function get_full_comment_text(): ?string { 3658 if ( self::STATE_FUNKY_COMMENT === $this->parser_state ) { 3659 return $this->get_modifiable_text(); 3660 } 3661 3662 if ( self::STATE_COMMENT !== $this->parser_state ) { 3663 return null; 3664 } 3665 3666 switch ( $this->get_comment_type() ) { 3667 case self::COMMENT_AS_HTML_COMMENT: 3668 case self::COMMENT_AS_ABRUPTLY_CLOSED_COMMENT: 3669 return $this->get_modifiable_text(); 3670 3671 case self::COMMENT_AS_CDATA_LOOKALIKE: 3672 return "[CDATA[{$this->get_modifiable_text()}]]"; 3673 3674 case self::COMMENT_AS_PI_NODE_LOOKALIKE: 3675 return "?{$this->get_tag()}{$this->get_modifiable_text()}?"; 3676 3677 /* 3678 * This represents "bogus comments state" from HTML tokenization. 3679 * This can be entered by `<?` or `<!`, where `?` is included in 3680 * the comment text but `!` is not. 3681 */ 3682 case self::COMMENT_AS_INVALID_HTML: 3683 $preceding_character = $this->html[ $this->text_starts_at - 1 ]; 3684 $comment_start = '?' === $preceding_character ? '?' : ''; 3685 return "{$comment_start}{$this->get_modifiable_text()}"; 3686 } 3687 3688 return null; 3689 } 3690 3691 /** 3692 * Subdivides a matched text node, splitting NULL byte sequences and decoded whitespace as 3693 * distinct nodes prefixes. 3694 * 3695 * Note that once anything that's neither a NULL byte nor decoded whitespace is 3696 * encountered, then the remainder of the text node is left intact as generic text. 3697 * 3698 * - The HTML Processor uses this to apply distinct rules for different kinds of text. 3699 * - Inter-element whitespace can be detected and skipped with this method. 3700 * 3701 * Text nodes aren't eagerly subdivided because there's no need to split them unless 3702 * decisions are being made on NULL byte sequences or whitespace-only text. 3703 * 3704 * Example: 3705 * 3706 * $processor = new WP_HTML_Tag_Processor( "\x00Apples & Oranges" ); 3707 * true === $processor->next_token(); // Text is "Apples & Oranges". 3708 * true === $processor->subdivide_text_appropriately(); // Text is "". 3709 * true === $processor->next_token(); // Text is "Apples & Oranges". 3710 * false === $processor->subdivide_text_appropriately(); 3711 * 3712 * $processor = new WP_HTML_Tag_Processor( "
 \r\n\tMore" ); 3713 * true === $processor->next_token(); // Text is "␍ ␊␉More". 3714 * true === $processor->subdivide_text_appropriately(); // Text is "␍ ␊␉". 3715 * true === $processor->next_token(); // Text is "More". 3716 * false === $processor->subdivide_text_appropriately(); 3717 * 3718 * @since 6.7.0 3719 * 3720 * @return bool Whether the text node was subdivided. 3721 */ 3722 public function subdivide_text_appropriately(): bool { 3723 if ( self::STATE_TEXT_NODE !== $this->parser_state ) { 3724 return false; 3725 } 3726 3727 $this->text_node_classification = self::TEXT_IS_GENERIC; 3728 3729 /* 3730 * NULL bytes are treated categorically different than numeric character 3731 * references whose number is zero. `�` is not the same as `"\x00"`. 3732 */ 3733 $leading_nulls = strspn( $this->html, "\x00", $this->text_starts_at, $this->text_length ); 3734 if ( $leading_nulls > 0 ) { 3735 $this->token_length = $leading_nulls; 3736 $this->text_length = $leading_nulls; 3737 $this->bytes_already_parsed = $this->token_starts_at + $leading_nulls; 3738 $this->text_node_classification = self::TEXT_IS_NULL_SEQUENCE; 3739 return true; 3740 } 3741 3742 /* 3743 * Start a decoding loop to determine the point at which the 3744 * text subdivides. This entails raw whitespace bytes and any 3745 * character reference that decodes to the same. 3746 */ 3747 $at = $this->text_starts_at; 3748 $end = $this->text_starts_at + $this->text_length; 3749 while ( $at < $end ) { 3750 $skipped = strspn( $this->html, " \t\f\r\n", $at, $end - $at ); 3751 $at += $skipped; 3752 3753 if ( $at < $end && '&' === $this->html[ $at ] ) { 3754 $matched_byte_length = null; 3755 $replacement = WP_HTML_Decoder::read_character_reference( 'data', $this->html, $at, $matched_byte_length ); 3756 if ( isset( $replacement ) && 1 === strspn( $replacement, " \t\f\r\n" ) ) { 3757 $at += $matched_byte_length; 3758 continue; 3759 } 3760 } 3761 3762 break; 3763 } 3764 3765 if ( $at > $this->text_starts_at ) { 3766 $new_length = $at - $this->text_starts_at; 3767 $this->text_length = $new_length; 3768 $this->token_length = $new_length; 3769 $this->bytes_already_parsed = $at; 3770 $this->text_node_classification = self::TEXT_IS_WHITESPACE; 3771 return true; 3772 } 3773 3774 return false; 3775 } 3776 3777 /** 3778 * Returns the modifiable text for a matched token, or an empty string. 3779 * 3780 * Modifiable text is text content that may be read and changed without 3781 * changing the HTML structure of the document around it. This includes 3782 * the contents of `#text` nodes in the HTML as well as the inner 3783 * contents of HTML comments, Processing Instructions, and others, even 3784 * though these nodes aren't part of a parsed DOM tree. They also contain 3785 * the contents of SCRIPT and STYLE tags, of TEXTAREA tags, and of any 3786 * other section in an HTML document which cannot contain HTML markup (DATA). 3787 * 3788 * If a token has no modifiable text then an empty string is returned to 3789 * avoid needless crashing or type errors. An empty string does not mean 3790 * that a token has modifiable text, and a token with modifiable text may 3791 * have an empty string (e.g. a comment with no contents). 3792 * 3793 * Limitations: 3794 * 3795 * - This function will not strip the leading newline appropriately 3796 * after seeking into a LISTING or PRE element. To ensure that the 3797 * newline is treated properly, seek to the LISTING or PRE opening 3798 * tag instead of to the first text node inside the element. 3799 * 3800 * @since 6.5.0 3801 * @since 6.7.0 Replaces NULL bytes (U+0000) and newlines appropriately. 3802 * 3803 * @return string 3804 */ 3805 public function get_modifiable_text(): string { 3806 $has_enqueued_update = isset( $this->lexical_updates['modifiable text'] ); 3807 3808 if ( ! $has_enqueued_update && ( null === $this->text_starts_at || 0 === $this->text_length ) ) { 3809 return ''; 3810 } 3811 3812 $text = $has_enqueued_update 3813 ? $this->lexical_updates['modifiable text']->text 3814 : substr( $this->html, $this->text_starts_at, $this->text_length ); 3815 3816 /** 3817 * An enqueued processing instruction update holds normalized raw 3818 * syntax spanning from the end of the target through the end of 3819 * the token: a separating space, the data, and the `?>` closer. 3820 * The data is found by skipping the leading whitespace and 3821 * dropping the two bytes of the closer. 3822 * 3823 * @see WP_HTML_Tag_Processor::set_modifiable_text() 3824 */ 3825 if ( $has_enqueued_update && self::STATE_PROCESSING_INSTRUCTION === $this->parser_state ) { 3826 $text = substr( $text, strspn( $text, " \t\f\r\n" ), -2 ); 3827 } 3828 3829 /* 3830 * Pre-processing the input stream would normally happen before 3831 * any parsing is done, but deferring it means it's possible to 3832 * skip in most cases. When getting the modifiable text, however 3833 * it's important to apply the pre-processing steps, which is 3834 * normalizing newlines. 3835 * 3836 * @see https://html.spec.whatwg.org/#preprocessing-the-input-stream 3837 * @see https://infra.spec.whatwg.org/#normalize-newlines 3838 */ 3839 $text = str_replace( "\r\n", "\n", $text ); 3840 $text = str_replace( "\r", "\n", $text ); 3841 3842 // Comment and processing instruction data is not decoded. 3843 if ( 3844 self::STATE_CDATA_NODE === $this->parser_state || 3845 self::STATE_COMMENT === $this->parser_state || 3846 self::STATE_DOCTYPE === $this->parser_state || 3847 self::STATE_FUNKY_COMMENT === $this->parser_state || 3848 self::STATE_PROCESSING_INSTRUCTION === $this->parser_state 3849 ) { 3850 return str_replace( "\x00", "\u{FFFD}", $text ); 3851 } 3852 3853 $tag_name = $this->get_token_name(); 3854 if ( 3855 // Script data is not decoded. 3856 'SCRIPT' === $tag_name || 3857 3858 // RAWTEXT data is not decoded. 3859 'IFRAME' === $tag_name || 3860 'NOEMBED' === $tag_name || 3861 'NOFRAMES' === $tag_name || 3862 'STYLE' === $tag_name || 3863 'XMP' === $tag_name 3864 ) { 3865 return str_replace( "\x00", "\u{FFFD}", $text ); 3866 } 3867 3868 $decoded = WP_HTML_Decoder::decode_text_node( $text ); 3869 3870 /* 3871 * Skip the first line feed after LISTING, PRE, and TEXTAREA opening tags. 3872 * 3873 * Note that this first newline may come in the form of a character 3874 * reference, such as `
`, and so it's important to perform 3875 * this transformation only after decoding the raw text content. 3876 */ 3877 if ( 3878 ( "\n" === ( $decoded[0] ?? '' ) ) && 3879 ( ( $this->skip_newline_at === $this->token_starts_at && '#text' === $tag_name ) || 'TEXTAREA' === $tag_name ) 3880 ) { 3881 $decoded = substr( $decoded, 1 ); 3882 } 3883 3884 /* 3885 * Only in normative text nodes does the NULL byte (U+0000) get removed. 3886 * In all other contexts it's replaced by the replacement character (U+FFFD) 3887 * for security reasons (to avoid joining together strings that were safe 3888 * when separated, but not when joined). 3889 * 3890 * @todo Inside HTML integration points and MathML integration points, the 3891 * text is processed according to the insertion mode, not according 3892 * to the foreign content rules. This should strip the NULL bytes. 3893 */ 3894 return ( '#text' === $tag_name && 'html' === $this->get_namespace() ) 3895 ? str_replace( "\x00", '', $decoded ) 3896 : str_replace( "\x00", "\u{FFFD}", $decoded ); 3897 } 3898 3899 /** 3900 * Sets the modifiable text for the matched token, if matched. 3901 * 3902 * Modifiable text is text content that may be read and changed without 3903 * changing the HTML structure of the document around it. This includes 3904 * the contents of `#text` nodes in the HTML as well as the inner 3905 * contents of HTML comments, Processing Instructions, and others, even 3906 * though these nodes aren't part of a parsed DOM tree. They also contain 3907 * the contents of SCRIPT and STYLE tags, of TEXTAREA tags, and of any 3908 * other section in an HTML document which cannot contain HTML markup (DATA). 3909 * 3910 * Not all modifiable text may be set by this method, and not all content 3911 * may be set as modifiable text. In the case that this fails it will return 3912 * `false` indicating as much. For instance, if the contents of a SCRIPT 3913 * element are neither JavaScript nor JSON, it’s not possible to guarantee 3914 * that escaping strings like `</script>` won’t break the script; in these 3915 * cases, updates will be rejected and it’s up to calling code to perform 3916 * language-specific escaping or workarounds. Similarly, it will not allow 3917 * setting content into a comment which would prematurely terminate the comment, 3918 * or processing instruction data which cannot be represented: data containing 3919 * a `>`, which would prematurely terminate the processing instruction, or data 3920 * with leading whitespace, which is indistinguishable from the whitespace 3921 * separating the data from its target. 3922 * 3923 * Example: 3924 * 3925 * // Add a preface to all STYLE contents. 3926 * while ( $processor->next_tag( 'STYLE' ) ) { 3927 * $style = $processor->get_modifiable_text(); 3928 * $processor->set_modifiable_text( "// Made with love on the World Wide Web\n{$style}" ); 3929 * } 3930 * 3931 * // Replace smiley text with Emoji smilies. 3932 * while ( $processor->next_token() ) { 3933 * if ( '#text' !== $processor->get_token_name() ) { 3934 * continue; 3935 * } 3936 * 3937 * $chunk = $processor->get_modifiable_text(); 3938 * if ( ! str_contains( $chunk, ':)' ) ) { 3939 * continue; 3940 * } 3941 * 3942 * $processor->set_modifiable_text( str_replace( ':)', '🙂', $chunk ) ); 3943 * } 3944 * 3945 * This function handles all necessary HTML encoding. Provide normal, unescaped string values. 3946 * The HTML API will encode the strings appropriately so that the browser will interpret them 3947 * as the intended value. 3948 * 3949 * Example: 3950 * 3951 * // Renders as “Eggs & Milk” in a browser, encoded as `<p>Eggs & Milk</p>`. 3952 * $processor->set_modifiable_text( 'Eggs & Milk' ); 3953 * 3954 * // Renders as “Eggs & Milk” in a browser, encoded as `<p>Eggs &amp; Milk</p>`. 3955 * $processor->set_modifiable_text( 'Eggs & Milk' ); 3956 * 3957 * @since 6.7.0 3958 * @since 6.9.0 Escapes all character references instead of trying to avoid double-escaping. 3959 * @since 7.1.0 Supports setting processing instruction data. 3960 * @since 7.2.0 Escapes content inside TITLE and TEXTAREA elements. 3961 * 3962 * @param string $plaintext_content New text content to represent in the matched token. 3963 * @return bool Whether the text was able to update. 3964 */ 3965 public function set_modifiable_text( string $plaintext_content ): bool { 3966 if ( self::STATE_TEXT_NODE === $this->parser_state ) { 3967 $this->lexical_updates['modifiable text'] = new WP_HTML_Text_Replacement( 3968 $this->text_starts_at, 3969 $this->text_length, 3970 strtr( 3971 $plaintext_content, 3972 array( 3973 '<' => '<', 3974 '>' => '>', 3975 '&' => '&', 3976 '"' => '"', 3977 "'" => ''', 3978 ) 3979 ) 3980 ); 3981 3982 return true; 3983 } 3984 3985 // Comment data is not encoded. 3986 if ( 3987 self::STATE_COMMENT === $this->parser_state && 3988 self::COMMENT_AS_HTML_COMMENT === $this->comment_type 3989 ) { 3990 // Check if the text could close the comment. 3991 if ( 1 === preg_match( '/^-?>|--!?>/', $plaintext_content ) ) { 3992 _doing_it_wrong( 3993 __METHOD__, 3994 __( 'Comment text cannot contain a comment closer.' ), 3995 '7.1.0' 3996 ); 3997 return false; 3998 } 3999 4000 $this->lexical_updates['modifiable text'] = new WP_HTML_Text_Replacement( 4001 $this->text_starts_at, 4002 $this->text_length, 4003 $plaintext_content 4004 ); 4005 4006 return true; 4007 } 4008 4009 // Processing instruction data is not encoded. 4010 if ( self::STATE_PROCESSING_INSTRUCTION === $this->parser_state ) { 4011 /* 4012 * A processing instruction ends at the first `>` in its 4013 * raw syntax: data containing one cannot be represented. 4014 */ 4015 if ( str_contains( $plaintext_content, '>' ) ) { 4016 _doing_it_wrong( 4017 __METHOD__, 4018 __( 'Processing instruction data cannot contain ">".' ), 4019 '7.1.0' 4020 ); 4021 return false; 4022 } 4023 4024 /* 4025 * All whitespace between the target and the data is skipped when 4026 * parsing: data with leading whitespace cannot be represented. 4027 */ 4028 if ( 0 !== strspn( $plaintext_content, " \t\f\r\n" ) ) { 4029 _doing_it_wrong( 4030 __METHOD__, 4031 __( 'Processing instruction data cannot start with whitespace. Try ltrim( $plaintext_content, " \t\f\r\n" ).' ), 4032 '7.1.0' 4033 ); 4034 return false; 4035 } 4036 4037 /** 4038 * A single replacement spans from the end of the target through 4039 * the end of the token, normalizing the raw syntax for that 4040 * region into a fixed form: a separating space, the data, and 4041 * the `?>` closer. 4042 * 4043 * {@see self::get_modifiable_text()} performs necessary parsing to 4044 * return the correct processing instruction data based 4045 * on the modifiable text lexical update. 4046 */ 4047 $data_at = $this->tag_name_starts_at + $this->tag_name_length; 4048 4049 $this->lexical_updates['modifiable text'] = new WP_HTML_Text_Replacement( 4050 $data_at, 4051 $this->token_starts_at + $this->token_length - $data_at, 4052 " {$plaintext_content}?>" 4053 ); 4054 4055 return true; 4056 } 4057 4058 /* 4059 * The rest of this function handles modifiable text for special "atomic" HTML elements. 4060 * Only tags in the HTML namespace should be processed. 4061 */ 4062 if ( 4063 self::STATE_MATCHED_TAG !== $this->parser_state || 4064 'html' !== $this->get_namespace() 4065 ) { 4066 _doing_it_wrong( 4067 __METHOD__, 4068 __( 'This token does not support setting modifiable text.' ), 4069 '7.1.0' 4070 ); 4071 return false; 4072 } 4073 4074 switch ( $this->get_tag() ) { 4075 case 'SCRIPT': 4076 $script_content_type = $this->get_script_content_type(); 4077 4078 switch ( $script_content_type ) { 4079 case 'javascript': 4080 case 'json': 4081 $this->lexical_updates['modifiable text'] = new WP_HTML_Text_Replacement( 4082 $this->text_starts_at, 4083 $this->text_length, 4084 self::escape_javascript_script_contents( $plaintext_content ) 4085 ); 4086 return true; 4087 } 4088 4089 /* 4090 * If the script’s content type isn’t recognized and understandable then it’s 4091 * impossible to guarantee that escaping the content won’t cause runtime breakage. 4092 * For instance, if the script content type were PHP code then escaping with 4093 * `\u0073` would not be met by unescaping; rather, it could result in corrupted 4094 * data or even syntax errors. 4095 * 4096 * Because of this, content which could potentially modify the SCRIPT tag’s 4097 * HTML structure is rejected here. It’s the responsibility of calling code to 4098 * perform whatever semantic escaping is necessary to avoid problematic strings. 4099 * 4100 * Both the start tag `<script` and the end tag `</script` are rejected. It’s 4101 * easy to assume that only an end tag can alter the HTML structure, but a 4102 * start tag which follows `<!--` moves the tokenizer into the double-escaped 4103 * states, where a later `</script>` no longer closes the element. 4104 * 4105 * In both cases the tag name ends only at one of the characters matched 4106 * below, so text such as `</scriptx>` cannot change that structure and is 4107 * safe to set. 4108 * 4109 * @link https://html.spec.whatwg.org/#script-data-end-tag-name-state 4110 * @link https://html.spec.whatwg.org/#script-data-double-escape-start-state 4111 */ 4112 if ( 1 === preg_match( '~</?script[ \t\f\r\n/>]~i', $plaintext_content ) ) { 4113 _doing_it_wrong( 4114 __METHOD__, 4115 __( 'SCRIPT text with an unrecognized content type cannot contain a SCRIPT tag. Apply the escaping appropriate for the content type.' ), 4116 '7.1.0' 4117 ); 4118 return false; 4119 } 4120 $this->lexical_updates['modifiable text'] = new WP_HTML_Text_Replacement( 4121 $this->text_starts_at, 4122 $this->text_length, 4123 $plaintext_content 4124 ); 4125 return true; 4126 4127 case 'IFRAME': 4128 case 'NOEMBED': 4129 case 'NOFRAMES': 4130 case 'XMP': 4131 $tag_name = $this->get_tag(); 4132 4133 /* 4134 * A tag name ends only at one of the characters matched below, so text 4135 * such as `</xmp-tag>` cannot close the element and is safe to set. 4136 * 4137 * @link https://html.spec.whatwg.org/#rawtext-end-tag-name-state 4138 */ 4139 if ( 1 === preg_match( '~</' . preg_quote( $tag_name, '~' ) . '[ \t\f\r\n/>]~i', $plaintext_content ) ) { 4140 _doing_it_wrong( 4141 __METHOD__, 4142 sprintf( 4143 /* translators: %s: HTML tag name. */ 4144 __( '%s text cannot contain its own closing tag.' ), 4145 $tag_name 4146 ), 4147 '7.1.0' 4148 ); 4149 return false; 4150 } 4151 4152 $this->lexical_updates['modifiable text'] = new WP_HTML_Text_Replacement( 4153 $this->text_starts_at, 4154 $this->text_length, 4155 $plaintext_content 4156 ); 4157 4158 return true; 4159 4160 case 'STYLE': 4161 $plaintext_content = preg_replace_callback( 4162 '~</(?P<TAG_NAME>style)~i', 4163 static function ( $tag_match ) { 4164 return "\\3c\\2f{$tag_match['TAG_NAME']}"; 4165 }, 4166 $plaintext_content 4167 ); 4168 4169 $this->lexical_updates['modifiable text'] = new WP_HTML_Text_Replacement( 4170 $this->text_starts_at, 4171 $this->text_length, 4172 $plaintext_content 4173 ); 4174 4175 return true; 4176 4177 case 'TEXTAREA': 4178 case 'TITLE': 4179 /** 4180 * While not expressly required, escaping syntax characters in these 4181 * elements will help avoid problems with downstream parser which 4182 * attempt to parse tags and other markup within. {@see \DOMDocument}, 4183 * for example, will claim to find elements as children of a `TITLE`. 4184 */ 4185 $plaintext_content = strtr( 4186 $plaintext_content, 4187 array( 4188 '<' => '<', 4189 '&' => '&', 4190 '>' => '>', 4191 ) 4192 ); 4193 4194 /* 4195 * HTML ignores a single leading newline in this context. If a leading newline 4196 * is intended, preserve it by adding an extra newline. 4197 */ 4198 if ( 4199 'TEXTAREA' === $this->get_tag() && 4200 1 === strspn( $plaintext_content, "\n\r", 0, 1 ) 4201 ) { 4202 $plaintext_content = "\n{$plaintext_content}"; 4203 } 4204 4205 /* 4206 * These don't _need_ to be escaped, but since they are decoded it's 4207 * safe to leave them escaped and this can prevent other code from 4208 * naively detecting tags within the contents. 4209 * 4210 * @todo It would be useful to prefix a multiline replacement text 4211 * with a newline, but not necessary. This is for aesthetics. 4212 */ 4213 $this->lexical_updates['modifiable text'] = new WP_HTML_Text_Replacement( 4214 $this->text_starts_at, 4215 $this->text_length, 4216 $plaintext_content 4217 ); 4218 4219 return true; 4220 } 4221 4222 _doing_it_wrong( 4223 __METHOD__, 4224 __( 'Only the IFRAME, NOEMBED, NOFRAMES, SCRIPT, STYLE, TEXTAREA, TITLE, and XMP tags support setting modifiable text.' ), 4225 '7.1.0' 4226 ); 4227 return false; 4228 } 4229 4230 /** 4231 * Returns the content type of the currently-matched HTML SCRIPT tag, if matched and 4232 * recognized, otherwise returns `null` to indicate an unrecognized content type. 4233 * 4234 * An HTML SCRIPT tag is a normal SCRIPT tag, but there can be SCRIPT elements inside 4235 * SVG and MathML elements as well, and these have different parsing rules than those 4236 * in general HTML. For this reason, no content-type inference is performed on those. 4237 * 4238 * Note! This concept is related but distinct from the MIME type of the script. 4239 * Parsing MUST match the specific algorithm in the HTML specification, which 4240 * relies on exact string comparison in some cases. MIME type decoding may be 4241 * performed on SVG or MathML SCRIPT tags. 4242 * 4243 * Only 'javascript' and 'json' content types are currently recognized. 4244 * 4245 * @see https://html.spec.whatwg.org/multipage/scripting.html#prepare-the-script-element 4246 * 4247 * @since 7.0.0 4248 * @ignore 4249 * 4250 * @return 'javascript'|'json'|null Type of script element content if matched and recognized. 4251 */ 4252 private function get_script_content_type(): ?string { 4253 // SVG and MathML SCRIPT elements are not recognized. 4254 if ( 'SCRIPT' !== $this->get_tag() || $this->get_namespace() !== 'html' ) { 4255 return null; 4256 } 4257 4258 /* 4259 * > If any of the following are true: 4260 * > - el has a type attribute whose value is the empty string; 4261 * > - el has no type attribute but it has a language attribute and that attribute's 4262 * > value is the empty string; or 4263 * > - el has neither a type attribute nor a language attribute, 4264 * > then let the script block's type string for this script element be "text/javascript". 4265 */ 4266 $type = $this->get_attribute( 'type' ); 4267 $lang = $this->get_attribute( 'language' ); 4268 4269 if ( true === $type || '' === $type ) { 4270 return 'javascript'; 4271 } 4272 4273 if ( null === $type && ( null === $lang || true === $lang || '' === $lang ) ) { 4274 return 'javascript'; 4275 } 4276 4277 /* 4278 * > Otherwise, if el has a type attribute, then let the script block's type string be 4279 * > the value of that attribute with leading and trailing ASCII whitespace stripped. 4280 * > Otherwise, el has a non-empty language attribute; let the script block's type string 4281 * > be the concatenation of "text/" and the value of el's language attribute. 4282 */ 4283 $type_string = is_string( $type ) ? trim( $type, " \t\f\r\n" ) : "text/{$lang}"; 4284 4285 // All matches are ASCII case-insensitive; eagerly lower-case for comparison. 4286 $type_string = strtolower( $type_string ); 4287 4288 /* 4289 * > If the script block's type string is a JavaScript MIME type essence match, then 4290 * > set el's type to "classic". 4291 * 4292 * > A string is a JavaScript MIME type essence match if it is an ASCII case-insensitive 4293 * > match for one of the JavaScript MIME type essence strings. 4294 * 4295 * > A JavaScript MIME type is any MIME type whose essence is one of the following: 4296 * > 4297 * > - application/ecmascript 4298 * > - application/javascript 4299 * > - application/x-ecmascript 4300 * > - application/x-javascript 4301 * > - text/ecmascript 4302 * > - text/javascript 4303 * > - text/javascript1.0 4304 * > - text/javascript1.1 4305 * > - text/javascript1.2 4306 * > - text/javascript1.3 4307 * > - text/javascript1.4 4308 * > - text/javascript1.5 4309 * > - text/jscript 4310 * > - text/livescript 4311 * > - text/x-ecmascript 4312 * > - text/x-javascript 4313 * 4314 * @see https://mimesniff.spec.whatwg.org/#javascript-mime-type-essence-match 4315 * @see https://mimesniff.spec.whatwg.org/#javascript-mime-type 4316 */ 4317 switch ( $type_string ) { 4318 case 'application/ecmascript': 4319 case 'application/javascript': 4320 case 'application/x-ecmascript': 4321 case 'application/x-javascript': 4322 case 'text/ecmascript': 4323 case 'text/javascript': 4324 case 'text/javascript1.0': 4325 case 'text/javascript1.1': 4326 case 'text/javascript1.2': 4327 case 'text/javascript1.3': 4328 case 'text/javascript1.4': 4329 case 'text/javascript1.5': 4330 case 'text/jscript': 4331 case 'text/livescript': 4332 case 'text/x-ecmascript': 4333 case 'text/x-javascript': 4334 return 'javascript'; 4335 4336 /* 4337 * > Otherwise, if the script block's type string is an ASCII case-insensitive match for 4338 * > the string "module", then set el's type to "module". 4339 * 4340 * A module is evaluated as JavaScript. 4341 */ 4342 case 'module': 4343 return 'javascript'; 4344 4345 /* 4346 * > 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". 4347 * > 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". 4348 * 4349 * These conditions indicate JSON content. 4350 */ 4351 case 'importmap': 4352 case 'speculationrules': 4353 return 'json'; 4354 4355 /** @todo Rely on a full MIME parser for determining JSON content. */ 4356 case 'application/json': 4357 case 'text/json': 4358 return 'json'; 4359 } 4360 4361 /* 4362 * > Otherwise, return. (No script is executed, and el's type is left as null.) 4363 */ 4364 return null; 4365 } 4366 4367 /** 4368 * Escape JavaScript and JSON script tag contents. 4369 * 4370 * Ensure that the script contents cannot modify the HTML structure or break out 4371 * of its containing SCRIPT element. JavaScript and JSON may both be escaped with 4372 * the same rules, even though there are additional escaping measures available 4373 * to JavaScript source code which aren’t applicable to serialized JSON data. 4374 * 4375 * A simple method safely escapes all content except for a few extremely rare and 4376 * unlikely exceptions: prevent the appearance of `<script` and `</script` within 4377 * the contents by replacing the first letter of the tag name with a Unicode escape. 4378 * 4379 * Example: 4380 * 4381 * $plaintext = '<script>document.write( "A </script> closes a script." );</script>'; 4382 * $escaped = '<script>document.write( "A </\u0073cript> closes a script." );</script>'; 4383 * 4384 * This works because of how parsing changes after encountering an opening SCRIPT 4385 * tag. The actual parsing comprises a complicated state machine, the result of 4386 * legacy behaviors and diverse browser support. However, without these two strings 4387 * in the script contents, two key things are ensured: `</script>` cannot appear to 4388 * prematurely close the tag, and the problematic double-escaped state becomes 4389 * unreachable. A JavaScript engine or JSON decoder will then decode the Unicode 4390 * escape (`\u0073`) back into its original plaintext value, but only after having 4391 * been safely extracted from the HTML. 4392 * 4393 * While it may seem tempting to replace the `<` character instead, doing so would 4394 * break JavaScript syntax. The `<` character is used in comparison operators and 4395 * other JavaScript syntax; replacing it would break valid JavaScript. Replacing 4396 * only the `s` in `<script` and `</script` avoids modifying JavaScript syntax. 4397 * 4398 * ### Exceptions 4399 * 4400 * This _should_ work everywhere, but there are some extreme exceptions. 4401 * 4402 * - Comments. 4403 * - Tagged templates, such as `String.raw()`, which provide access to “raw” strings. 4404 * - The `source` property of a RegExp object. 4405 * 4406 * Each of these exceptions appear at the source code level, not at the semantic or 4407 * evaluation level. Normal JavaScript will remain semantically equivalent after escaping, 4408 * but any JavaScript which analyzes the raw source code will see potentially-different 4409 * values. 4410 * 4411 * #### Comments 4412 * 4413 * Comments are never unescaped because they aren’t parsed by the JavaScript engine. 4414 * When viewing the source in a browser’s developer tools, the comments will retain 4415 * their escaped text. 4416 * 4417 * Example: 4418 * 4419 * // A comment: "</script>" 4420 * …becomes… 4421 * // A comment: "</\u0073cript>" 4422 * 4423 * #### Tagged templates. 4424 * 4425 * Tagged templates “enable the embedding of arbitrary string content, where escape 4426 * sequences may follow a different syntax.” For example, they can aid representing 4427 * a RegExp pattern or LaTex snippet within a JavaScript string, where the string 4428 * escape characters might get noisy and distracting. 4429 * 4430 * Example: 4431 * 4432 * console.log( 'A \notin B' ); // Prints a newline because of the "\n". 4433 * console.log( 'A \\notin B' ); // Prints "A \notin B". 4434 * console.log( String.raw`A \notin B` ); // Prints "A \notin B". 4435 * 4436 * This means that if `<script` transforms into `<\u0073cript` _inside_ a raw string 4437 * or tagged template literal which relies on its `.raw` property, the output of the 4438 * code will be different after escaping. 4439 * 4440 * Example: 4441 * 4442 * console.log( String.raw`</script>` ); // Prematurely closes the SCRIPT element. 4443 * console.log( String.raw`</\u0073cript>` ); // Prints "</\u0073cript". 4444 * 4445 * #### RegExp sources. 4446 * 4447 * The RegExp object exposes its raw source in a similar way to how tagged templates and raw 4448 * strings do. Thankfully, because escape sequences are decoded when compiling the pattern, 4449 * escaped RegExp patterns will match the same way as the plaintext sequences would. 4450 * 4451 * Example: 4452 * 4453 * true === /<script>/.test( '<script>' ); 4454 * true === /<\u0073cript>/.test( '<script>' ); 4455 * 4456 * However, as with raw strings, any code which reads the source will see the escaped value 4457 * instead of the decoded one. 4458 * 4459 * Example: 4460 * 4461 * console.log( /<script>/.source ); // Prints "<script>". 4462 * console.log( /<\u0073cript>/.source ); // Prints "<\u0073cript>". 4463 * 4464 * #### Unsupported escaping. 4465 * 4466 * It is not possible to properly represent every possible JavaScript source file 4467 * inside a SCRIPT element. As with CSS stylesheets, SVG images, and MathML, the 4468 * only 100% reliable way to represent all possible inputs is to link to external 4469 * files of the given content-type. 4470 * 4471 * In some cases it’s possible to manually prevent escaping issues. These are not 4472 * automatically handled by this function because doing so would require a full 4473 * JavaScript tokenizer. Consider the following example listing various ways to 4474 * manually escape a closing script tag. 4475 * 4476 * Example: 4477 * 4478 * console.log( String.raw`</script>` ); // !!UNSAFE!! Will be escaped. 4479 * console.log( String.raw`</\u0073cript>` ); // "</\u0073cript>" 4480 * console.log( String.raw`</scr` + String.raw`ipt>` ); // "</script>" 4481 * console.log( String.raw`</${"script"}>` ); // "</script>" 4482 * console.log( '</scr' + 'ipt>' ); // "</script>" 4483 * console.log( "\x3C/script>" ); // "</script>" 4484 * console.log( "<\/script>" ); // "</script>" 4485 * 4486 * The following graph is a simplified interpretation of how HTML interprets the contents 4487 * of a SCRIPT tag and identifies the closing tag. It is useful to understand what text 4488 * is dangerous inside of a SCRIPT tag and why different approaches to escaping work. 4489 * 4490 * Open script 4491 * │ 4492 * ▼ 4493 * ╔═════════════════════════════════════════╗ <!--(…)> 4494 * ║ ║ (all dashes) 4495 * ║ script ╟────────────────╮ 4496 * ║ data ║ │ 4497 * ╭───────────╢ ║ ◀──────────────╯ 4498 * │ ╚═╤═══════════════════════════════════════╝ 4499 * │ │ ▲ ▲ 4500 * │ │ <!-- │ --> ╰─────╮ 4501 * │ ▼ │ │ 4502 * │ ┌─────────────────┴───────────────────────┐ │ 4503 * │ </script¹ │ escaped │ │ 4504 * │ └─┬─────────────────────────────┬─────────┘ │ 4505 * │ │ ▲ │ │ --> 4506 * │ │ </script¹ │ </script¹ │ <script¹ │ 4507 * │ ▼ │ ▼ │ 4508 * │ ╔══════════════╗ │ ┌───────────┐ │ 4509 * │ ║ Close script ║ │ │ double │ │ 4510 * ╰──────────▶║ ║ ╰───────────┤ escaped ├──╯ 4511 * ╚══════════════╝ └───────────┘ 4512 * 4513 * ¹ = Case insensitive 'script' followed by one of ' \t\f\r\n/>', known 4514 * as “tag-name-terminating characters.” This sequence forms the start 4515 * of what could be a SCRIPT opening or closing tag. 4516 * 4517 * @see https://html.spec.whatwg.org/#restrictions-for-contents-of-script-elements 4518 * @see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Template_literals#specifications 4519 * @see wp_html_api_script_element_escaping_diagram_source() 4520 * 4521 * @since 7.0.0 4522 * @ignore 4523 * 4524 * @param string $sourcecode Raw contents intended to be serialized into an HTML SCRIPT element. 4525 * @return string Escaped form of input contents which will not lead to premature closing of the containing SCRIPT element. 4526 */ 4527 private static function escape_javascript_script_contents( string $sourcecode ): string { 4528 $at = 0; 4529 $was_at = 0; 4530 $end = strlen( $sourcecode ); 4531 $escaped = ''; 4532 4533 /* 4534 * Replace all instances of the ASCII case-insensitive match of "<script" 4535 * and "</script", when followed by whitespace or "/" or ">", by using a 4536 * character replacement for the "s" (or the "S"). 4537 */ 4538 while ( $at < $end ) { 4539 $tag_at = strpos( $sourcecode, '<', $at ); 4540 if ( false === $tag_at ) { 4541 break; 4542 } 4543 4544 $tag_name_at = $tag_at + 1; 4545 $has_closing_slash = $tag_name_at < $end && '/' === $sourcecode[ $tag_name_at ]; 4546 $tag_name_at += $has_closing_slash ? 1 : 0; 4547 4548 if ( 0 !== substr_compare( $sourcecode, 'script', $tag_name_at, 6, true ) ) { 4549 $at = $tag_at + 1; 4550 continue; 4551 } 4552 4553 if ( 1 !== strspn( $sourcecode, " \t\f\r\n/>", $tag_name_at + 6, 1 ) ) { 4554 $at = $tag_name_at + 6; 4555 continue; 4556 } 4557 4558 $escaped .= substr( $sourcecode, $was_at, $tag_name_at - $was_at ); 4559 $escaped .= 's' === $sourcecode[ $tag_name_at ] ? '\u0073' : '\u0053'; 4560 $was_at = $tag_name_at + 1; 4561 $at = $tag_name_at + 7; 4562 } 4563 4564 if ( '' === $escaped ) { 4565 return $sourcecode; 4566 } 4567 4568 if ( $was_at < $end ) { 4569 $escaped .= substr( $sourcecode, $was_at ); 4570 } 4571 4572 return $escaped; 4573 } 4574 4575 /** 4576 * Updates or creates a new attribute on the currently matched tag with the passed value. 4577 * 4578 * This function handles all necessary HTML encoding. Provide normal, unescaped string values. 4579 * The HTML API will encode the strings appropriately so that the browser will interpret them 4580 * as the intended value. 4581 * 4582 * Example: 4583 * 4584 * // Renders “Eggs & Milk” in a browser, encoded as `<abbr title="Eggs & Milk">`. 4585 * $processor->set_attribute( 'title', 'Eggs & Milk' ); 4586 * 4587 * // Renders “Eggs & Milk” in a browser, encoded as `<abbr title="Eggs &amp; Milk">`. 4588 * $processor->set_attribute( 'title', 'Eggs & Milk' ); 4589 * 4590 * // Renders `true` as `<abbr title>`. 4591 * $processor->set_attribute( 'title', true ); 4592 * 4593 * // Renders without the attribute for `false` as `<abbr>`. 4594 * $processor->set_attribute( 'title', false ); 4595 * 4596 * Special handling is provided for boolean attribute values: 4597 * - When `true` is passed as the value, then only the attribute name is added to the tag. 4598 * - When `false` is passed, the attribute gets removed if it existed before. 4599 * 4600 * @since 6.2.0 4601 * @since 6.2.1 Fix: Only create a single update for multiple calls with case-variant attribute names. 4602 * @since 6.9.0 Escapes all character references instead of trying to avoid double-escaping. 4603 * 4604 * @param string $name The attribute name to target. 4605 * @param string|bool $value The new attribute value. 4606 * @return bool Whether an attribute value was set. 4607 */ 4608 public function set_attribute( $name, $value ): bool { 4609 if ( 4610 self::STATE_MATCHED_TAG !== $this->parser_state || 4611 $this->is_closing_tag 4612 ) { 4613 return false; 4614 } 4615 4616 $name_length = strlen( $name ); 4617 4618 /** 4619 * WordPress rejects more characters than are strictly forbidden 4620 * in HTML5. This is to prevent additional security risks deeper 4621 * in the WordPress and plugin stack. Specifically the following 4622 * are not allowed to be set as part of an HTML attribute name: 4623 * 4624 * - greater-than “>” 4625 * - ampersand “&” 4626 * 4627 * @see https://html.spec.whatwg.org/#attributes-2 4628 */ 4629 if ( 4630 0 === $name_length || 4631 // Syntax-like characters. 4632 strcspn( $name, '"\'>&</ =' ) !== $name_length || 4633 // Control characters. 4634 strcspn( 4635 $name, 4636 "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0A\x0B\x0C\x0D\x0E\x0F" . 4637 "\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1A\x1B\x1C\x1D\x1E\x1F" 4638 ) !== $name_length || 4639 // Unicode noncharacters. 4640 wp_has_noncharacters( $name ) 4641 ) { 4642 _doing_it_wrong( 4643 __METHOD__, 4644 __( 'Invalid attribute name.' ), 4645 '6.2.0' 4646 ); 4647 4648 return false; 4649 } 4650 4651 /* 4652 * > The values "true" and "false" are not allowed on boolean attributes. 4653 * > To represent a false value, the attribute has to be omitted altogether. 4654 * - HTML5 spec, https://html.spec.whatwg.org/#boolean-attributes 4655 */ 4656 if ( false === $value ) { 4657 return $this->remove_attribute( $name ); 4658 } 4659 4660 if ( true === $value ) { 4661 $updated_attribute = $name; 4662 } else { 4663 $comparable_name = strtolower( $name ); 4664 4665 /** 4666 * Escape attribute values appropriately. 4667 * 4668 * @see https://html.spec.whatwg.org/#attributes-3 4669 */ 4670 $escaped_new_value = in_array( $comparable_name, wp_kses_uri_attributes(), true ) 4671 ? esc_url( $value ) 4672 : strtr( 4673 $value, 4674 array( 4675 '<' => '<', 4676 '>' => '>', 4677 '&' => '&', 4678 '"' => '"', 4679 "'" => ''', 4680 ) 4681 ); 4682 4683 // If the escaping functions wiped out the update, reject it and indicate it was rejected. 4684 if ( '' === $escaped_new_value && '' !== $value ) { 4685 return false; 4686 } 4687 4688 $updated_attribute = "{$name}=\"{$escaped_new_value}\""; 4689 } 4690 4691 /* 4692 * > There must never be two or more attributes on 4693 * > the same start tag whose names are an ASCII 4694 * > case-insensitive match for each other. 4695 * - HTML 5 spec 4696 * 4697 * @see https://html.spec.whatwg.org/multipage/syntax.html#attributes-2:ascii-case-insensitive 4698 */ 4699 $comparable_name = strtolower( $name ); 4700 4701 if ( isset( $this->attributes[ $comparable_name ] ) ) { 4702 /* 4703 * Update an existing attribute. 4704 * 4705 * Example – set attribute id to "new" in <div id="initial_id" />: 4706 * 4707 * <div id="initial_id"/> 4708 * ^-------------^ 4709 * start end 4710 * replacement: `id="new"` 4711 * 4712 * Result: <div id="new"/> 4713 */ 4714 $existing_attribute = $this->attributes[ $comparable_name ]; 4715 $this->lexical_updates[ $comparable_name ] = new WP_HTML_Text_Replacement( 4716 $existing_attribute->start, 4717 $existing_attribute->length, 4718 $updated_attribute 4719 ); 4720 } else { 4721 /* 4722 * Create a new attribute at the tag's name end. 4723 * 4724 * Example – add attribute id="new" to <div />: 4725 * 4726 * <div/> 4727 * ^ 4728 * start and end 4729 * replacement: ` id="new"` 4730 * 4731 * Result: <div id="new"/> 4732 */ 4733 $this->lexical_updates[ $comparable_name ] = new WP_HTML_Text_Replacement( 4734 $this->tag_name_starts_at + $this->tag_name_length, 4735 0, 4736 ' ' . $updated_attribute 4737 ); 4738 } 4739 4740 /* 4741 * Any calls to update the `class` attribute directly should wipe out any 4742 * enqueued class changes from `add_class` and `remove_class`. 4743 */ 4744 if ( 'class' === $comparable_name && ! empty( $this->classname_updates ) ) { 4745 $this->classname_updates = array(); 4746 } 4747 4748 return true; 4749 } 4750 4751 /** 4752 * Remove an attribute from the currently-matched tag. 4753 * 4754 * @since 6.2.0 4755 * 4756 * @param string $name The attribute name to remove. 4757 * @return bool Whether an attribute was removed. 4758 */ 4759 public function remove_attribute( $name ): bool { 4760 if ( 4761 self::STATE_MATCHED_TAG !== $this->parser_state || 4762 $this->is_closing_tag 4763 ) { 4764 return false; 4765 } 4766 4767 /* 4768 * > There must never be two or more attributes on 4769 * > the same start tag whose names are an ASCII 4770 * > case-insensitive match for each other. 4771 * - HTML 5 spec 4772 * 4773 * @see https://html.spec.whatwg.org/multipage/syntax.html#attributes-2:ascii-case-insensitive 4774 */ 4775 $name = strtolower( $name ); 4776 4777 /* 4778 * Any calls to update the `class` attribute directly should wipe out any 4779 * enqueued class changes from `add_class` and `remove_class`. 4780 */ 4781 if ( 'class' === $name && count( $this->classname_updates ) !== 0 ) { 4782 $this->classname_updates = array(); 4783 } 4784 4785 /* 4786 * If updating an attribute that didn't exist in the input 4787 * document, then remove the enqueued update and move on. 4788 * 4789 * For example, this might occur when calling `remove_attribute()` 4790 * after calling `set_attribute()` for the same attribute 4791 * and when that attribute wasn't originally present. 4792 */ 4793 if ( ! isset( $this->attributes[ $name ] ) ) { 4794 if ( isset( $this->lexical_updates[ $name ] ) ) { 4795 unset( $this->lexical_updates[ $name ] ); 4796 } 4797 return false; 4798 } 4799 4800 /* 4801 * Removes an existing tag attribute. 4802 * 4803 * Example – remove the attribute id from <div id="main"/>: 4804 * <div id="initial_id"/> 4805 * ^-------------^ 4806 * start end 4807 * replacement: `` 4808 * 4809 * Result: <div /> 4810 */ 4811 $this->lexical_updates[ $name ] = new WP_HTML_Text_Replacement( 4812 $this->attributes[ $name ]->start, 4813 $this->attributes[ $name ]->length, 4814 '' 4815 ); 4816 4817 // Removes any duplicated attributes if they were also present. 4818 foreach ( $this->duplicate_attributes[ $name ] ?? array() as $attribute_token ) { 4819 $this->lexical_updates[] = new WP_HTML_Text_Replacement( 4820 $attribute_token->start, 4821 $attribute_token->length, 4822 '' 4823 ); 4824 } 4825 4826 return true; 4827 } 4828 4829 /** 4830 * Adds a new class name to the currently matched tag. 4831 * 4832 * @since 6.2.0 4833 * 4834 * @param string $class_name The class name to add. 4835 * @return bool Whether the class was set to be added. 4836 */ 4837 public function add_class( $class_name ): bool { 4838 if ( 4839 self::STATE_MATCHED_TAG !== $this->parser_state || 4840 $this->is_closing_tag 4841 ) { 4842 return false; 4843 } 4844 4845 if ( self::QUIRKS_MODE !== $this->compat_mode ) { 4846 $this->classname_updates[ $class_name ] = self::ADD_CLASS; 4847 return true; 4848 } 4849 4850 /* 4851 * Because class names are matched ASCII-case-insensitively in quirks mode, 4852 * this needs to see if a case variant of the given class name is already 4853 * enqueued and update that existing entry, if so. This picks the casing of 4854 * the first-provided class name for all lexical variations. 4855 */ 4856 $class_name_length = strlen( $class_name ); 4857 foreach ( $this->classname_updates as $updated_name => $action ) { 4858 if ( 4859 strlen( $updated_name ) === $class_name_length && 4860 0 === substr_compare( $updated_name, $class_name, 0, $class_name_length, true ) 4861 ) { 4862 $this->classname_updates[ $updated_name ] = self::ADD_CLASS; 4863 return true; 4864 } 4865 } 4866 4867 $this->classname_updates[ $class_name ] = self::ADD_CLASS; 4868 return true; 4869 } 4870 4871 /** 4872 * Removes a class name from the currently matched tag. 4873 * 4874 * @since 6.2.0 4875 * 4876 * @param string $class_name The class name to remove. 4877 * @return bool Whether the class was set to be removed. 4878 */ 4879 public function remove_class( $class_name ): bool { 4880 if ( 4881 self::STATE_MATCHED_TAG !== $this->parser_state || 4882 $this->is_closing_tag 4883 ) { 4884 return false; 4885 } 4886 4887 if ( self::QUIRKS_MODE !== $this->compat_mode ) { 4888 $this->classname_updates[ $class_name ] = self::REMOVE_CLASS; 4889 return true; 4890 } 4891 4892 /* 4893 * Because class names are matched ASCII-case-insensitively in quirks mode, 4894 * this needs to see if a case variant of the given class name is already 4895 * enqueued and update that existing entry, if so. This picks the casing of 4896 * the first-provided class name for all lexical variations. 4897 */ 4898 $class_name_length = strlen( $class_name ); 4899 foreach ( $this->classname_updates as $updated_name => $action ) { 4900 if ( 4901 strlen( $updated_name ) === $class_name_length && 4902 0 === substr_compare( $updated_name, $class_name, 0, $class_name_length, true ) 4903 ) { 4904 $this->classname_updates[ $updated_name ] = self::REMOVE_CLASS; 4905 return true; 4906 } 4907 } 4908 4909 $this->classname_updates[ $class_name ] = self::REMOVE_CLASS; 4910 return true; 4911 } 4912 4913 /** 4914 * Returns the string representation of the HTML Tag Processor. 4915 * 4916 * @since 6.2.0 4917 * 4918 * @see WP_HTML_Tag_Processor::get_updated_html() 4919 * 4920 * @return string The processed HTML. 4921 */ 4922 public function __toString(): string { 4923 return $this->get_updated_html(); 4924 } 4925 4926 /** 4927 * Returns the string representation of the HTML Tag Processor. 4928 * 4929 * @since 6.2.0 4930 * @since 6.2.1 Shifts the internal cursor corresponding to the applied updates. 4931 * @since 6.4.0 No longer calls subclass method `next_tag()` after updating HTML. 4932 * 4933 * @return string The processed HTML. 4934 */ 4935 public function get_updated_html(): string { 4936 $requires_no_updating = 0 === count( $this->classname_updates ) && 0 === count( $this->lexical_updates ); 4937 4938 /* 4939 * When there is nothing more to update and nothing has already been 4940 * updated, return the original document and avoid a string copy. 4941 */ 4942 if ( $requires_no_updating ) { 4943 return $this->html; 4944 } 4945 4946 /* 4947 * Keep track of the position right before the current tag. This will 4948 * be necessary for reparsing the current tag after updating the HTML. 4949 */ 4950 $before_current_tag = $this->token_starts_at ?? 0; 4951 4952 /* 4953 * 1. Apply the enqueued edits and update all the pointers to reflect those changes. 4954 */ 4955 $this->class_name_updates_to_attributes_updates(); 4956 $before_current_tag += $this->apply_attributes_updates( $before_current_tag ); 4957 4958 /* 4959 * 2. Rewind to before the current tag and reparse to get updated attributes. 4960 * 4961 * At this point the internal cursor points to the end of the tag name. 4962 * Rewind before the tag name starts so that it's as if the cursor didn't 4963 * move; a call to `next_tag()` will reparse the recently-updated attributes 4964 * and additional calls to modify the attributes will apply at this same 4965 * location, but in order to avoid issues with subclasses that might add 4966 * behaviors to `next_tag()`, the internal methods should be called here 4967 * instead. 4968 * 4969 * It's important to note that in this specific place there will be no change 4970 * because the processor was already at a tag when this was called and it's 4971 * rewinding only to the beginning of this very tag before reprocessing it 4972 * and its attributes. 4973 * 4974 * <p>Previous HTML<em>More HTML</em></p> 4975 * ↑ │ back up by the length of the tag name plus the opening < 4976 * └←─┘ back up by strlen("em") + 1 ==> 3 4977 */ 4978 $this->bytes_already_parsed = $before_current_tag; 4979 $this->base_class_next_token(); 4980 4981 return $this->html; 4982 } 4983 4984 /** 4985 * Parses tag query input into internal search criteria. 4986 * 4987 * @since 6.2.0 4988 * @ignore 4989 * 4990 * @param array|string|null $query { 4991 * Optional. Which tag name to find, having which class, etc. Default is to find any tag. 4992 * 4993 * @type string|null $tag_name Which tag to find, or `null` for "any tag." 4994 * @type int|null $match_offset Find the Nth tag matching all search criteria. 4995 * 1 for "first" tag, 3 for "third," etc. 4996 * Defaults to first tag. 4997 * @type string|null $class_name Tag must contain this class name to match. 4998 * @type string $tag_closers "visit" or "skip": whether to stop on tag closers, e.g. </div>. 4999 * } 5000 */ 5001 private function parse_query( $query ) { 5002 if ( null !== $query && $query === $this->last_query ) { 5003 return; 5004 } 5005 5006 $this->last_query = $query; 5007 $this->sought_tag_name = null; 5008 $this->sought_class_name = null; 5009 $this->sought_match_offset = 1; 5010 $this->stop_on_tag_closers = false; 5011 5012 // A single string value means "find the tag of this name". 5013 if ( is_string( $query ) ) { 5014 $this->sought_tag_name = $query; 5015 return; 5016 } 5017 5018 // An empty query parameter applies no restrictions on the search. 5019 if ( null === $query ) { 5020 return; 5021 } 5022 5023 // If not using the string interface, an associative array is required. 5024 if ( ! is_array( $query ) ) { 5025 _doing_it_wrong( 5026 __METHOD__, 5027 __( 'The query argument must be an array or a tag name.' ), 5028 '6.2.0' 5029 ); 5030 return; 5031 } 5032 5033 if ( isset( $query['tag_name'] ) && is_string( $query['tag_name'] ) ) { 5034 $this->sought_tag_name = $query['tag_name']; 5035 } 5036 5037 if ( isset( $query['class_name'] ) && is_string( $query['class_name'] ) ) { 5038 $this->sought_class_name = $query['class_name']; 5039 } 5040 5041 if ( isset( $query['match_offset'] ) && is_int( $query['match_offset'] ) && 0 < $query['match_offset'] ) { 5042 $this->sought_match_offset = $query['match_offset']; 5043 } 5044 5045 if ( isset( $query['tag_closers'] ) ) { 5046 $this->stop_on_tag_closers = 'visit' === $query['tag_closers']; 5047 } 5048 } 5049 5050 5051 /** 5052 * Checks whether a given tag and its attributes match the search criteria. 5053 * 5054 * @since 6.2.0 5055 * @ignore 5056 * 5057 * @return bool Whether the given tag and its attribute match the search criteria. 5058 */ 5059 private function matches(): bool { 5060 if ( $this->is_closing_tag && ! $this->stop_on_tag_closers ) { 5061 return false; 5062 } 5063 5064 // Does the tag name match the requested tag name in a case-insensitive manner? 5065 if ( isset( $this->sought_tag_name ) ) { 5066 $tag_name = $this->get_tag(); 5067 if ( 5068 strlen( $this->sought_tag_name ) !== strlen( $tag_name ) || 5069 0 !== substr_compare( $tag_name, $this->sought_tag_name, 0, null, true ) 5070 ) { 5071 return false; 5072 } 5073 } 5074 5075 if ( null !== $this->sought_class_name && ! $this->has_class( $this->sought_class_name ) ) { 5076 return false; 5077 } 5078 5079 return true; 5080 } 5081 5082 /** 5083 * Gets DOCTYPE declaration info from a DOCTYPE token. 5084 * 5085 * DOCTYPE tokens may appear in many places in an HTML document. In most places, they are 5086 * simply ignored. The main parsing functions find the basic shape of DOCTYPE tokens but 5087 * do not perform detailed parsing. 5088 * 5089 * This method can be called to perform a full parse of the DOCTYPE token and retrieve 5090 * its information. 5091 * 5092 * @since 6.7.0 5093 * 5094 * @return WP_HTML_Doctype_Info|null The DOCTYPE declaration information or `null` if not 5095 * currently at a DOCTYPE node. 5096 */ 5097 public function get_doctype_info(): ?WP_HTML_Doctype_Info { 5098 if ( self::STATE_DOCTYPE !== $this->parser_state ) { 5099 return null; 5100 } 5101 5102 return WP_HTML_Doctype_Info::from_doctype_token( substr( $this->html, $this->token_starts_at, $this->token_length ) ); 5103 } 5104 5105 /** 5106 * Parser Ready State. 5107 * 5108 * Indicates that the parser is ready to run and waiting for a state transition. 5109 * It may not have started yet, or it may have just finished parsing a token and 5110 * is ready to find the next one. 5111 * 5112 * @since 6.5.0 5113 * 5114 * @access private 5115 */ 5116 const STATE_READY = 'STATE_READY'; 5117 5118 /** 5119 * Parser Complete State. 5120 * 5121 * Indicates that the parser has reached the end of the document and there is 5122 * nothing left to scan. It finished parsing the last token completely. 5123 * 5124 * @since 6.5.0 5125 * 5126 * @access private 5127 */ 5128 const STATE_COMPLETE = 'STATE_COMPLETE'; 5129 5130 /** 5131 * Parser Incomplete Input State. 5132 * 5133 * Indicates that the parser has reached the end of the document before finishing 5134 * a token. It started parsing a token but there is a possibility that the input 5135 * HTML document was truncated in the middle of a token. 5136 * 5137 * The parser is reset at the start of the incomplete token and has paused. There 5138 * is nothing more than can be scanned unless provided a more complete document. 5139 * 5140 * @since 6.5.0 5141 * 5142 * @access private 5143 */ 5144 const STATE_INCOMPLETE_INPUT = 'STATE_INCOMPLETE_INPUT'; 5145 5146 /** 5147 * Parser Matched Tag State. 5148 * 5149 * Indicates that the parser has found an HTML tag and it's possible to get 5150 * the tag name and read or modify its attributes (if it's not a closing tag). 5151 * 5152 * @since 6.5.0 5153 * 5154 * @access private 5155 */ 5156 const STATE_MATCHED_TAG = 'STATE_MATCHED_TAG'; 5157 5158 /** 5159 * Parser Text Node State. 5160 * 5161 * Indicates that the parser has found a text node and it's possible 5162 * to read and modify that text. 5163 * 5164 * @since 6.5.0 5165 * 5166 * @access private 5167 */ 5168 const STATE_TEXT_NODE = 'STATE_TEXT_NODE'; 5169 5170 /** 5171 * Parser CDATA Node State. 5172 * 5173 * Indicates that the parser has found a CDATA node and it's possible 5174 * to read and modify its modifiable text. Note that in HTML there are 5175 * no CDATA nodes outside of foreign content (SVG and MathML). Outside 5176 * of foreign content, they are treated as HTML comments. 5177 * 5178 * @since 6.5.0 5179 * 5180 * @access private 5181 */ 5182 const STATE_CDATA_NODE = 'STATE_CDATA_NODE'; 5183 5184 /** 5185 * Indicates that the parser has found an HTML comment and it's 5186 * possible to read and modify its modifiable text. 5187 * 5188 * @since 6.5.0 5189 * 5190 * @access private 5191 */ 5192 const STATE_COMMENT = 'STATE_COMMENT'; 5193 5194 /** 5195 * Indicates that the parser has found a DOCTYPE node and it's 5196 * possible to read its DOCTYPE information via `get_doctype_info()`. 5197 * 5198 * @since 6.5.0 5199 * 5200 * @access private 5201 */ 5202 const STATE_DOCTYPE = 'STATE_DOCTYPE'; 5203 5204 /** 5205 * Indicates that the parser has found an empty tag closer `</>`. 5206 * 5207 * Note that in HTML there are no empty tag closers, and they 5208 * are ignored. Nonetheless, the Tag Processor still 5209 * recognizes them as they appear in the HTML stream. 5210 * 5211 * These were historically discussed as a "presumptuous tag 5212 * closer," which would close the nearest open tag, but were 5213 * dismissed in favor of explicitly-closing tags. 5214 * 5215 * @since 6.5.0 5216 * 5217 * @access private 5218 */ 5219 const STATE_PRESUMPTUOUS_TAG = 'STATE_PRESUMPTUOUS_TAG'; 5220 5221 /** 5222 * Indicates that the parser has found a "funky comment" 5223 * and it's possible to read and modify its modifiable text. 5224 * 5225 * Example: 5226 * 5227 * </%url> 5228 * </{"wp-bit":"query/post-author"}> 5229 * </2> 5230 * 5231 * Funky comments are tag closers with invalid tag names. Note 5232 * that in HTML these are turned into bogus comments. Nonetheless, 5233 * the Tag Processor recognizes them in a stream of HTML and 5234 * exposes them for inspection and modification. 5235 * 5236 * @since 6.5.0 5237 * 5238 * @access private 5239 */ 5240 const STATE_FUNKY_COMMENT = 'STATE_WP_FUNKY'; 5241 5242 /** 5243 * Indicates that the parser has found a processing instruction 5244 * and it's possible to read its target and data. 5245 * 5246 * Example: 5247 * 5248 * <?wp-bit {"just": "kidding"}> 5249 * 5250 * Processing instructions with an allowable target are parsed 5251 * into processing instruction nodes. The reserved `xml` and 5252 * `xml-stylesheet` targets, and targets with characters outside 5253 * an ASCII-representable subset, are turned into bogus comments. 5254 * 5255 * @link https://html.spec.whatwg.org/multipage/parsing.html#processing-instruction-open-state 5256 * 5257 * @since 7.1.0 5258 * 5259 * @access private 5260 */ 5261 const STATE_PROCESSING_INSTRUCTION = 'STATE_PROCESSING_INSTRUCTION'; 5262 5263 /** 5264 * Indicates that a comment was created when encountering abruptly-closed HTML comment. 5265 * 5266 * Example: 5267 * 5268 * <!--> 5269 * <!---> 5270 * 5271 * @since 6.5.0 5272 */ 5273 const COMMENT_AS_ABRUPTLY_CLOSED_COMMENT = 'COMMENT_AS_ABRUPTLY_CLOSED_COMMENT'; 5274 5275 /** 5276 * Indicates that a comment would be parsed as a CDATA node, 5277 * were HTML to allow CDATA nodes outside of foreign content. 5278 * 5279 * Example: 5280 * 5281 * <![CDATA[This is a CDATA node.]]> 5282 * 5283 * This is an HTML comment, but it looks like a CDATA node. 5284 * 5285 * @since 6.5.0 5286 */ 5287 const COMMENT_AS_CDATA_LOOKALIKE = 'COMMENT_AS_CDATA_LOOKALIKE'; 5288 5289 /** 5290 * Indicates that a comment was created when encountering 5291 * normative HTML comment syntax. 5292 * 5293 * Example: 5294 * 5295 * <!-- this is a comment --> 5296 * 5297 * @since 6.5.0 5298 */ 5299 const COMMENT_AS_HTML_COMMENT = 'COMMENT_AS_HTML_COMMENT'; 5300 5301 /** 5302 * Indicates that a comment would be parsed as a Processing 5303 * Instruction node, were its target allowed within HTML. 5304 * 5305 * Example: 5306 * 5307 * <?xml version="1.0" ?> 5308 * <?wp.like count=5 ?> 5309 * 5310 * These are HTML comments, but they look like processing 5311 * instructions. HTML parses processing instructions with 5312 * an allowable target into processing instruction nodes, 5313 * but the reserved `xml` and `xml-stylesheet` targets and 5314 * XML-valid targets with characters outside of the allowed 5315 * set become bogus comments instead. 5316 * 5317 * @since 6.5.0 5318 * @since 7.1.0 Only applies to reserved and XML-specific target names; 5319 * other processing instructions produce their own token. 5320 */ 5321 const COMMENT_AS_PI_NODE_LOOKALIKE = 'COMMENT_AS_PI_NODE_LOOKALIKE'; 5322 5323 /** 5324 * Indicates that a comment was created when encountering invalid 5325 * HTML input, a so-called "bogus comment." 5326 * 5327 * Example: 5328 * 5329 * <?= nothing special ?> 5330 * <!{nothing special}> 5331 * 5332 * @since 6.5.0 5333 */ 5334 const COMMENT_AS_INVALID_HTML = 'COMMENT_AS_INVALID_HTML'; 5335 5336 /** 5337 * No-quirks mode document compatibility mode. 5338 * 5339 * > In no-quirks mode, the behavior is (hopefully) the desired behavior 5340 * > described by the modern HTML and CSS specifications. 5341 * 5342 * @see self::$compat_mode 5343 * @see https://developer.mozilla.org/en-US/docs/Web/HTML/Quirks_Mode_and_Standards_Mode 5344 * 5345 * @since 6.7.0 5346 * 5347 * @var string 5348 */ 5349 const NO_QUIRKS_MODE = 'no-quirks-mode'; 5350 5351 /** 5352 * Quirks mode document compatibility mode. 5353 * 5354 * > In quirks mode, layout emulates behavior in Navigator 4 and Internet 5355 * > Explorer 5. This is essential in order to support websites that were 5356 * > built before the widespread adoption of web standards. 5357 * 5358 * @see self::$compat_mode 5359 * @see https://developer.mozilla.org/en-US/docs/Web/HTML/Quirks_Mode_and_Standards_Mode 5360 * 5361 * @since 6.7.0 5362 * 5363 * @var string 5364 */ 5365 const QUIRKS_MODE = 'quirks-mode'; 5366 5367 /** 5368 * Indicates that a span of text may contain any combination of significant 5369 * kinds of characters: NULL bytes, whitespace, and others. 5370 * 5371 * @see self::$text_node_classification 5372 * @see self::subdivide_text_appropriately 5373 * 5374 * @since 6.7.0 5375 */ 5376 const TEXT_IS_GENERIC = 'TEXT_IS_GENERIC'; 5377 5378 /** 5379 * Indicates that a span of text comprises a sequence only of NULL bytes. 5380 * 5381 * @see self::$text_node_classification 5382 * @see self::subdivide_text_appropriately 5383 * 5384 * @since 6.7.0 5385 */ 5386 const TEXT_IS_NULL_SEQUENCE = 'TEXT_IS_NULL_SEQUENCE'; 5387 5388 /** 5389 * Indicates that a span of decoded text comprises only whitespace. 5390 * 5391 * @see self::$text_node_classification 5392 * @see self::subdivide_text_appropriately 5393 * 5394 * @since 6.7.0 5395 */ 5396 const TEXT_IS_WHITESPACE = 'TEXT_IS_WHITESPACE'; 5397 5398 /** 5399 * Wakeup magic method. 5400 * 5401 * @since 6.9.2 5402 */ 5403 public function __wakeup() { 5404 throw new \LogicException( __CLASS__ . ' should never be unserialized' ); 5405 } 5406 }
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