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