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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 the 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`, `NOSCRIPT`, `NOEMBED`, `NOFRAME`, `STYLE` 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 * - XML 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]: XML allows a broader range of characters in a processing instruction's target name 329 * and disallows "xml" as a name, since it's special. The Tag Processor only recognizes 330 * target names with an ASCII-representable subset of characters. It also exhibits the 331 * same constraint as with CDATA sections, in that `>` cannot exist within the token 332 * since Processing Instructions do no exist within HTML and their syntax transforms 333 * into a bogus comment in the DOM. 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 * 497 * @since 6.5.0 498 * 499 * @see WP_HTML_Tag_Processor::STATE_READY 500 * @see WP_HTML_Tag_Processor::STATE_COMPLETE 501 * @see WP_HTML_Tag_Processor::STATE_INCOMPLETE_INPUT 502 * @see WP_HTML_Tag_Processor::STATE_MATCHED_TAG 503 * @see WP_HTML_Tag_Processor::STATE_TEXT_NODE 504 * @see WP_HTML_Tag_Processor::STATE_CDATA_NODE 505 * @see WP_HTML_Tag_Processor::STATE_COMMENT 506 * @see WP_HTML_Tag_Processor::STATE_DOCTYPE 507 * @see WP_HTML_Tag_Processor::STATE_PRESUMPTUOUS_TAG 508 * @see WP_HTML_Tag_Processor::STATE_FUNKY_COMMENT 509 * 510 * @var string 511 */ 512 protected $parser_state = self::STATE_READY; 513 514 /** 515 * Indicates if the document is in quirks mode or no-quirks mode. 516 * 517 * Impact on HTML parsing: 518 * 519 * - In `NO_QUIRKS_MODE` (also known as "standard mode"): 520 * - CSS class and ID selectors match byte-for-byte (case-sensitively). 521 * - A TABLE start tag `<table>` implicitly closes any open `P` element. 522 * 523 * - In `QUIRKS_MODE`: 524 * - CSS class and ID selectors match match in an ASCII case-insensitive manner. 525 * - A TABLE start tag `<table>` opens a `TABLE` element as a child of a `P` 526 * element if one is open. 527 * 528 * Quirks and no-quirks mode are thus mostly about styling, but have an impact when 529 * tables are found inside paragraph elements. 530 * 531 * @see self::QUIRKS_MODE 532 * @see self::NO_QUIRKS_MODE 533 * 534 * @since 6.7.0 535 * 536 * @var string 537 */ 538 protected $compat_mode = self::NO_QUIRKS_MODE; 539 540 /** 541 * Indicates whether the parser is inside foreign content, 542 * e.g. inside an SVG or MathML element. 543 * 544 * One of 'html', 'svg', or 'math'. 545 * 546 * Several parsing rules change based on whether the parser 547 * is inside foreign content, including whether CDATA sections 548 * are allowed and whether a self-closing flag indicates that 549 * an element has no content. 550 * 551 * @since 6.7.0 552 * 553 * @var string 554 */ 555 private $parsing_namespace = 'html'; 556 557 /** 558 * What kind of syntax token became an HTML comment. 559 * 560 * Since there are many ways in which HTML syntax can create an HTML comment, 561 * this indicates which of those caused it. This allows the Tag Processor to 562 * represent more from the original input document than would appear in the DOM. 563 * 564 * @since 6.5.0 565 * 566 * @var string|null 567 */ 568 protected $comment_type = null; 569 570 /** 571 * What kind of text the matched text node represents, if it was subdivided. 572 * 573 * @see self::TEXT_IS_NULL_SEQUENCE 574 * @see self::TEXT_IS_WHITESPACE 575 * @see self::TEXT_IS_GENERIC 576 * @see self::subdivide_text_appropriately 577 * 578 * @since 6.7.0 579 * 580 * @var string 581 */ 582 protected $text_node_classification = self::TEXT_IS_GENERIC; 583 584 /** 585 * How many bytes from the original HTML document have been read and parsed. 586 * 587 * This value points to the latest byte offset in the input document which 588 * has been already parsed. It is the internal cursor for the Tag Processor 589 * and updates while scanning through the HTML tokens. 590 * 591 * @since 6.2.0 592 * @var int 593 */ 594 private $bytes_already_parsed = 0; 595 596 /** 597 * Byte offset in input document where current token starts. 598 * 599 * Example: 600 * 601 * <div id="test">... 602 * 01234 603 * - token starts at 0 604 * 605 * @since 6.5.0 606 * 607 * @var int|null 608 */ 609 private $token_starts_at; 610 611 /** 612 * Byte length of current token. 613 * 614 * Example: 615 * 616 * <div id="test">... 617 * 012345678901234 618 * - token length is 14 - 0 = 14 619 * 620 * a <!-- comment --> is a token. 621 * 0123456789 123456789 123456789 622 * - token length is 17 - 2 = 15 623 * 624 * @since 6.5.0 625 * 626 * @var int|null 627 */ 628 private $token_length; 629 630 /** 631 * Byte offset in input document where current tag name starts. 632 * 633 * Example: 634 * 635 * <div id="test">... 636 * 01234 637 * - tag name starts at 1 638 * 639 * @since 6.2.0 640 * 641 * @var int|null 642 */ 643 private $tag_name_starts_at; 644 645 /** 646 * Byte length of current tag name. 647 * 648 * Example: 649 * 650 * <div id="test">... 651 * 01234 652 * --- tag name length is 3 653 * 654 * @since 6.2.0 655 * 656 * @var int|null 657 */ 658 private $tag_name_length; 659 660 /** 661 * Byte offset into input document where current modifiable text starts. 662 * 663 * @since 6.5.0 664 * 665 * @var int 666 */ 667 private $text_starts_at; 668 669 /** 670 * Byte length of modifiable text. 671 * 672 * @since 6.5.0 673 * 674 * @var int 675 */ 676 private $text_length; 677 678 /** 679 * Whether the current tag is an opening tag, e.g. <div>, or a closing tag, e.g. </div>. 680 * 681 * @var bool 682 */ 683 private $is_closing_tag; 684 685 /** 686 * Lazily-built index of attributes found within an HTML tag, keyed by the attribute name. 687 * 688 * Example: 689 * 690 * // Supposing the parser is working through this content 691 * // and stops after recognizing the `id` attribute. 692 * // <div id="test-4" class=outline title="data:text/plain;base64=asdk3nk1j3fo8"> 693 * // ^ parsing will continue from this point. 694 * $this->attributes = array( 695 * 'id' => new WP_HTML_Attribute_Token( 'id', 9, 6, 5, 11, false ) 696 * ); 697 * 698 * // When picking up parsing again, or when asking to find the 699 * // `class` attribute we will continue and add to this array. 700 * $this->attributes = array( 701 * 'id' => new WP_HTML_Attribute_Token( 'id', 9, 6, 5, 11, false ), 702 * 'class' => new WP_HTML_Attribute_Token( 'class', 23, 7, 17, 13, false ) 703 * ); 704 * 705 * // Note that only the `class` attribute value is stored in the index. 706 * // That's because it is the only value used by this class at the moment. 707 * 708 * @since 6.2.0 709 * @var WP_HTML_Attribute_Token[] 710 */ 711 private $attributes = array(); 712 713 /** 714 * Tracks spans of duplicate attributes on a given tag, used for removing 715 * all copies of an attribute when calling `remove_attribute()`. 716 * 717 * @since 6.3.2 718 * 719 * @var (WP_HTML_Span[])[]|null 720 */ 721 private $duplicate_attributes = null; 722 723 /** 724 * Which class names to add or remove from a tag. 725 * 726 * These are tracked separately from attribute updates because they are 727 * semantically distinct, whereas this interface exists for the common 728 * case of adding and removing class names while other attributes are 729 * generally modified as with DOM `setAttribute` calls. 730 * 731 * When modifying an HTML document these will eventually be collapsed 732 * into a single `set_attribute( 'class', $changes )` call. 733 * 734 * Example: 735 * 736 * // Add the `wp-block-group` class, remove the `wp-group` class. 737 * $classname_updates = array( 738 * // Indexed by a comparable class name. 739 * 'wp-block-group' => WP_HTML_Tag_Processor::ADD_CLASS, 740 * 'wp-group' => WP_HTML_Tag_Processor::REMOVE_CLASS 741 * ); 742 * 743 * @since 6.2.0 744 * @var bool[] 745 */ 746 private $classname_updates = array(); 747 748 /** 749 * Tracks a semantic location in the original HTML which 750 * shifts with updates as they are applied to the document. 751 * 752 * @since 6.2.0 753 * @var WP_HTML_Span[] 754 */ 755 protected $bookmarks = array(); 756 757 const ADD_CLASS = true; 758 const REMOVE_CLASS = false; 759 const SKIP_CLASS = null; 760 761 /** 762 * Lexical replacements to apply to input HTML document. 763 * 764 * "Lexical" in this class refers to the part of this class which 765 * operates on pure text _as text_ and not as HTML. There's a line 766 * between the public interface, with HTML-semantic methods like 767 * `set_attribute` and `add_class`, and an internal state that tracks 768 * text offsets in the input document. 769 * 770 * When higher-level HTML methods are called, those have to transform their 771 * operations (such as setting an attribute's value) into text diffing 772 * operations (such as replacing the sub-string from indices A to B with 773 * some given new string). These text-diffing operations are the lexical 774 * updates. 775 * 776 * As new higher-level methods are added they need to collapse their 777 * operations into these lower-level lexical updates since that's the 778 * Tag Processor's internal language of change. Any code which creates 779 * these lexical updates must ensure that they do not cross HTML syntax 780 * boundaries, however, so these should never be exposed outside of this 781 * class or any classes which intentionally expand its functionality. 782 * 783 * These are enqueued while editing the document instead of being immediately 784 * applied to avoid processing overhead, string allocations, and string 785 * copies when applying many updates to a single document. 786 * 787 * Example: 788 * 789 * // Replace an attribute stored with a new value, indices 790 * // sourced from the lazily-parsed HTML recognizer. 791 * $start = $attributes['src']->start; 792 * $length = $attributes['src']->length; 793 * $modifications[] = new WP_HTML_Text_Replacement( $start, $length, $new_value ); 794 * 795 * // Correspondingly, something like this will appear in this array. 796 * $lexical_updates = array( 797 * WP_HTML_Text_Replacement( 14, 28, 'https://my-site.my-domain/wp-content/uploads/2014/08/kittens.jpg' ) 798 * ); 799 * 800 * @since 6.2.0 801 * @var WP_HTML_Text_Replacement[] 802 */ 803 protected $lexical_updates = array(); 804 805 /** 806 * Tracks and limits `seek()` calls to prevent accidental infinite loops. 807 * 808 * @since 6.2.0 809 * @var int 810 * 811 * @see WP_HTML_Tag_Processor::seek() 812 */ 813 protected $seek_count = 0; 814 815 /** 816 * Whether the parser should skip over an immediately-following linefeed 817 * character, as is the case with LISTING, PRE, and TEXTAREA. 818 * 819 * > If the next token is a U+000A LINE FEED (LF) character token, then 820 * > ignore that token and move on to the next one. (Newlines at the start 821 * > of [these] elements are ignored as an authoring convenience.) 822 * 823 * @since 6.7.0 824 * 825 * @var int|null 826 */ 827 private $skip_newline_at = null; 828 829 /** 830 * Constructor. 831 * 832 * @since 6.2.0 833 * 834 * @param string $html HTML to process. 835 */ 836 public function __construct( $html ) { 837 $this->html = $html; 838 } 839 840 /** 841 * Switches parsing mode into a new namespace, such as when 842 * encountering an SVG tag and entering foreign content. 843 * 844 * @since 6.7.0 845 * 846 * @param string $new_namespace One of 'html', 'svg', or 'math' indicating into what 847 * namespace the next tokens will be processed. 848 * @return bool Whether the namespace was valid and changed. 849 */ 850 public function change_parsing_namespace( string $new_namespace ): bool { 851 if ( ! in_array( $new_namespace, array( 'html', 'math', 'svg' ), true ) ) { 852 return false; 853 } 854 855 $this->parsing_namespace = $new_namespace; 856 return true; 857 } 858 859 /** 860 * Finds the next tag matching the $query. 861 * 862 * @since 6.2.0 863 * @since 6.5.0 No longer processes incomplete tokens at end of document; pauses the processor at start of token. 864 * 865 * @param array|string|null $query { 866 * Optional. Which tag name to find, having which class, etc. Default is to find any tag. 867 * 868 * @type string|null $tag_name Which tag to find, or `null` for "any tag." 869 * @type int|null $match_offset Find the Nth tag matching all search criteria. 870 * 1 for "first" tag, 3 for "third," etc. 871 * Defaults to first tag. 872 * @type string|null $class_name Tag must contain this whole class name to match. 873 * @type string|null $tag_closers "visit" or "skip": whether to stop on tag closers, e.g. </div>. 874 * } 875 * @return bool Whether a tag was matched. 876 */ 877 public function next_tag( $query = null ): bool { 878 $this->parse_query( $query ); 879 $already_found = 0; 880 881 do { 882 if ( false === $this->next_token() ) { 883 return false; 884 } 885 886 if ( self::STATE_MATCHED_TAG !== $this->parser_state ) { 887 continue; 888 } 889 890 if ( $this->matches() ) { 891 ++$already_found; 892 } 893 } while ( $already_found < $this->sought_match_offset ); 894 895 return true; 896 } 897 898 /** 899 * Finds the next token in the HTML document. 900 * 901 * An HTML document can be viewed as a stream of tokens, 902 * where tokens are things like HTML tags, HTML comments, 903 * text nodes, etc. This method finds the next token in 904 * the HTML document and returns whether it found one. 905 * 906 * If it starts parsing a token and reaches the end of the 907 * document then it will seek to the start of the last 908 * token and pause, returning `false` to indicate that it 909 * failed to find a complete token. 910 * 911 * Possible token types, based on the HTML specification: 912 * 913 * - an HTML tag, whether opening, closing, or void. 914 * - a text node - the plaintext inside tags. 915 * - an HTML comment. 916 * - a DOCTYPE declaration. 917 * - a processing instruction, e.g. `<?xml version="1.0" ?>`. 918 * 919 * The Tag Processor currently only supports the tag token. 920 * 921 * @since 6.5.0 922 * @since 6.7.0 Recognizes CDATA sections within foreign content. 923 * 924 * @return bool Whether a token was parsed. 925 */ 926 public function next_token(): bool { 927 return $this->base_class_next_token(); 928 } 929 930 /** 931 * Internal method which finds the next token in the HTML document. 932 * 933 * This method is a protected internal function which implements the logic for 934 * finding the next token in a document. It exists so that the parser can update 935 * its state without affecting the location of the cursor in the document and 936 * without triggering subclass methods for things like `next_token()`, e.g. when 937 * applying patches before searching for the next token. 938 * 939 * @since 6.5.0 940 * 941 * @access private 942 * 943 * @return bool Whether a token was parsed. 944 */ 945 private function base_class_next_token(): bool { 946 $was_at = $this->bytes_already_parsed; 947 $this->after_tag(); 948 949 // Don't proceed if there's nothing more to scan. 950 if ( 951 self::STATE_COMPLETE === $this->parser_state || 952 self::STATE_INCOMPLETE_INPUT === $this->parser_state 953 ) { 954 return false; 955 } 956 957 /* 958 * The next step in the parsing loop determines the parsing state; 959 * clear it so that state doesn't linger from the previous step. 960 */ 961 $this->parser_state = self::STATE_READY; 962 963 if ( $this->bytes_already_parsed >= strlen( $this->html ) ) { 964 $this->parser_state = self::STATE_COMPLETE; 965 return false; 966 } 967 968 // Find the next tag if it exists. 969 if ( false === $this->parse_next_tag() ) { 970 if ( self::STATE_INCOMPLETE_INPUT === $this->parser_state ) { 971 $this->bytes_already_parsed = $was_at; 972 } 973 974 return false; 975 } 976 977 /* 978 * For legacy reasons the rest of this function handles tags and their 979 * attributes. If the processor has reached the end of the document 980 * or if it matched any other token then it should return here to avoid 981 * attempting to process tag-specific syntax. 982 */ 983 if ( 984 self::STATE_INCOMPLETE_INPUT !== $this->parser_state && 985 self::STATE_COMPLETE !== $this->parser_state && 986 self::STATE_MATCHED_TAG !== $this->parser_state 987 ) { 988 return true; 989 } 990 991 // Parse all of its attributes. 992 while ( $this->parse_next_attribute() ) { 993 continue; 994 } 995 996 // Ensure that the tag closes before the end of the document. 997 if ( 998 self::STATE_INCOMPLETE_INPUT === $this->parser_state || 999 $this->bytes_already_parsed >= strlen( $this->html ) 1000 ) { 1001 // Does this appropriately clear state (parsed attributes)? 1002 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 1003 $this->bytes_already_parsed = $was_at; 1004 1005 return false; 1006 } 1007 1008 $tag_ends_at = strpos( $this->html, '>', $this->bytes_already_parsed ); 1009 if ( false === $tag_ends_at ) { 1010 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 1011 $this->bytes_already_parsed = $was_at; 1012 1013 return false; 1014 } 1015 $this->parser_state = self::STATE_MATCHED_TAG; 1016 $this->bytes_already_parsed = $tag_ends_at + 1; 1017 $this->token_length = $this->bytes_already_parsed - $this->token_starts_at; 1018 1019 /* 1020 * Certain tags require additional processing. The first-letter pre-check 1021 * avoids unnecessary string allocation when comparing the tag names. 1022 * 1023 * - IFRAME 1024 * - LISTING (deprecated) 1025 * - NOEMBED (deprecated) 1026 * - NOFRAMES (deprecated) 1027 * - PRE 1028 * - SCRIPT 1029 * - STYLE 1030 * - TEXTAREA 1031 * - TITLE 1032 * - XMP (deprecated) 1033 */ 1034 if ( 1035 $this->is_closing_tag || 1036 'html' !== $this->parsing_namespace || 1037 1 !== strspn( $this->html, 'iIlLnNpPsStTxX', $this->tag_name_starts_at, 1 ) 1038 ) { 1039 return true; 1040 } 1041 1042 $tag_name = $this->get_tag(); 1043 1044 /* 1045 * For LISTING, PRE, and TEXTAREA, the first linefeed of an immediately-following 1046 * text node is ignored as an authoring convenience. 1047 * 1048 * @see static::skip_newline_at 1049 */ 1050 if ( 'LISTING' === $tag_name || 'PRE' === $tag_name ) { 1051 $this->skip_newline_at = $this->bytes_already_parsed; 1052 return true; 1053 } 1054 1055 /* 1056 * There are certain elements whose children are not DATA but are instead 1057 * RCDATA or RAWTEXT. These cannot contain other elements, and the contents 1058 * are parsed as plaintext, with character references decoded in RCDATA but 1059 * not in RAWTEXT. 1060 * 1061 * These elements are described here as "self-contained" or special atomic 1062 * elements whose end tag is consumed with the opening tag, and they will 1063 * contain modifiable text inside of them. 1064 * 1065 * Preserve the opening tag pointers, as these will be overwritten 1066 * when finding the closing tag. They will be reset after finding 1067 * the closing to tag to point to the opening of the special atomic 1068 * tag sequence. 1069 */ 1070 $tag_name_starts_at = $this->tag_name_starts_at; 1071 $tag_name_length = $this->tag_name_length; 1072 $tag_ends_at = $this->token_starts_at + $this->token_length; 1073 $attributes = $this->attributes; 1074 $duplicate_attributes = $this->duplicate_attributes; 1075 1076 // Find the closing tag if necessary. 1077 switch ( $tag_name ) { 1078 case 'SCRIPT': 1079 $found_closer = $this->skip_script_data(); 1080 break; 1081 1082 case 'TEXTAREA': 1083 case 'TITLE': 1084 $found_closer = $this->skip_rcdata( $tag_name ); 1085 break; 1086 1087 /* 1088 * In the browser this list would include the NOSCRIPT element, 1089 * but the Tag Processor is an environment with the scripting 1090 * flag disabled, meaning that it needs to descend into the 1091 * NOSCRIPT element to be able to properly process what will be 1092 * sent to a browser. 1093 * 1094 * Note that this rule makes HTML5 syntax incompatible with XML, 1095 * because the parsing of this token depends on client application. 1096 * The NOSCRIPT element cannot be represented in the XHTML syntax. 1097 */ 1098 case 'IFRAME': 1099 case 'NOEMBED': 1100 case 'NOFRAMES': 1101 case 'STYLE': 1102 case 'XMP': 1103 $found_closer = $this->skip_rawtext( $tag_name ); 1104 break; 1105 1106 // No other tags should be treated in their entirety here. 1107 default: 1108 return true; 1109 } 1110 1111 if ( ! $found_closer ) { 1112 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 1113 $this->bytes_already_parsed = $was_at; 1114 return false; 1115 } 1116 1117 /* 1118 * The values here look like they reference the opening tag but they reference 1119 * the closing tag instead. This is why the opening tag values were stored 1120 * above in a variable. It reads confusingly here, but that's because the 1121 * functions that skip the contents have moved all the internal cursors past 1122 * the inner content of the tag. 1123 */ 1124 $this->token_starts_at = $was_at; 1125 $this->token_length = $this->bytes_already_parsed - $this->token_starts_at; 1126 $this->text_starts_at = $tag_ends_at; 1127 $this->text_length = $this->tag_name_starts_at - $this->text_starts_at; 1128 $this->tag_name_starts_at = $tag_name_starts_at; 1129 $this->tag_name_length = $tag_name_length; 1130 $this->attributes = $attributes; 1131 $this->duplicate_attributes = $duplicate_attributes; 1132 1133 return true; 1134 } 1135 1136 /** 1137 * Whether the processor paused because the input HTML document ended 1138 * in the middle of a syntax element, such as in the middle of a tag. 1139 * 1140 * Example: 1141 * 1142 * $processor = new WP_HTML_Tag_Processor( '<input type="text" value="Th' ); 1143 * false === $processor->get_next_tag(); 1144 * true === $processor->paused_at_incomplete_token(); 1145 * 1146 * @since 6.5.0 1147 * 1148 * @return bool Whether the parse paused at the start of an incomplete token. 1149 */ 1150 public function paused_at_incomplete_token(): bool { 1151 return self::STATE_INCOMPLETE_INPUT === $this->parser_state; 1152 } 1153 1154 /** 1155 * Generator for a foreach loop to step through each class name for the matched tag. 1156 * 1157 * This generator function is designed to be used inside a "foreach" loop. 1158 * 1159 * Example: 1160 * 1161 * $p = new WP_HTML_Tag_Processor( "<div class='free <egg<\tlang-en'>" ); 1162 * $p->next_tag(); 1163 * foreach ( $p->class_list() as $class_name ) { 1164 * echo "{$class_name} "; 1165 * } 1166 * // Outputs: "free <egg> lang-en " 1167 * 1168 * @since 6.4.0 1169 */ 1170 public function class_list() { 1171 if ( self::STATE_MATCHED_TAG !== $this->parser_state ) { 1172 return; 1173 } 1174 1175 /** @var string $class contains the string value of the class attribute, with character references decoded. */ 1176 $class = $this->get_attribute( 'class' ); 1177 1178 if ( ! is_string( $class ) ) { 1179 return; 1180 } 1181 1182 $seen = array(); 1183 1184 $is_quirks = self::QUIRKS_MODE === $this->compat_mode; 1185 1186 $at = 0; 1187 while ( $at < strlen( $class ) ) { 1188 // Skip past any initial boundary characters. 1189 $at += strspn( $class, " \t\f\r\n", $at ); 1190 if ( $at >= strlen( $class ) ) { 1191 return; 1192 } 1193 1194 // Find the byte length until the next boundary. 1195 $length = strcspn( $class, " \t\f\r\n", $at ); 1196 if ( 0 === $length ) { 1197 return; 1198 } 1199 1200 $name = str_replace( "\x00", "\u{FFFD}", substr( $class, $at, $length ) ); 1201 if ( $is_quirks ) { 1202 $name = strtolower( $name ); 1203 } 1204 $at += $length; 1205 1206 /* 1207 * It's expected that the number of class names for a given tag is relatively small. 1208 * Given this, it is probably faster overall to scan an array for a value rather 1209 * than to use the class name as a key and check if it's a key of $seen. 1210 */ 1211 if ( in_array( $name, $seen, true ) ) { 1212 continue; 1213 } 1214 1215 $seen[] = $name; 1216 yield $name; 1217 } 1218 } 1219 1220 1221 /** 1222 * Returns if a matched tag contains the given ASCII case-insensitive class name. 1223 * 1224 * @since 6.4.0 1225 * 1226 * @param string $wanted_class Look for this CSS class name, ASCII case-insensitive. 1227 * @return bool|null Whether the matched tag contains the given class name, or null if not matched. 1228 */ 1229 public function has_class( $wanted_class ): ?bool { 1230 if ( self::STATE_MATCHED_TAG !== $this->parser_state ) { 1231 return null; 1232 } 1233 1234 $case_insensitive = self::QUIRKS_MODE === $this->compat_mode; 1235 1236 $wanted_length = strlen( $wanted_class ); 1237 foreach ( $this->class_list() as $class_name ) { 1238 if ( 1239 strlen( $class_name ) === $wanted_length && 1240 0 === substr_compare( $class_name, $wanted_class, 0, strlen( $wanted_class ), $case_insensitive ) 1241 ) { 1242 return true; 1243 } 1244 } 1245 1246 return false; 1247 } 1248 1249 1250 /** 1251 * Sets a bookmark in the HTML document. 1252 * 1253 * Bookmarks represent specific places or tokens in the HTML 1254 * document, such as a tag opener or closer. When applying 1255 * edits to a document, such as setting an attribute, the 1256 * text offsets of that token may shift; the bookmark is 1257 * kept updated with those shifts and remains stable unless 1258 * the entire span of text in which the token sits is removed. 1259 * 1260 * Release bookmarks when they are no longer needed. 1261 * 1262 * Example: 1263 * 1264 * <main><h2>Surprising fact you may not know!</h2></main> 1265 * ^ ^ 1266 * \-|-- this `H2` opener bookmark tracks the token 1267 * 1268 * <main class="clickbait"><h2>Surprising fact you may no… 1269 * ^ ^ 1270 * \-|-- it shifts with edits 1271 * 1272 * Bookmarks provide the ability to seek to a previously-scanned 1273 * place in the HTML document. This avoids the need to re-scan 1274 * the entire document. 1275 * 1276 * Example: 1277 * 1278 * <ul><li>One</li><li>Two</li><li>Three</li></ul> 1279 * ^^^^ 1280 * want to note this last item 1281 * 1282 * $p = new WP_HTML_Tag_Processor( $html ); 1283 * $in_list = false; 1284 * while ( $p->next_tag( array( 'tag_closers' => $in_list ? 'visit' : 'skip' ) ) ) { 1285 * if ( 'UL' === $p->get_tag() ) { 1286 * if ( $p->is_tag_closer() ) { 1287 * $in_list = false; 1288 * $p->set_bookmark( 'resume' ); 1289 * if ( $p->seek( 'last-li' ) ) { 1290 * $p->add_class( 'last-li' ); 1291 * } 1292 * $p->seek( 'resume' ); 1293 * $p->release_bookmark( 'last-li' ); 1294 * $p->release_bookmark( 'resume' ); 1295 * } else { 1296 * $in_list = true; 1297 * } 1298 * } 1299 * 1300 * if ( 'LI' === $p->get_tag() ) { 1301 * $p->set_bookmark( 'last-li' ); 1302 * } 1303 * } 1304 * 1305 * Bookmarks intentionally hide the internal string offsets 1306 * to which they refer. They are maintained internally as 1307 * updates are applied to the HTML document and therefore 1308 * retain their "position" - the location to which they 1309 * originally pointed. The inability to use bookmarks with 1310 * functions like `substr` is therefore intentional to guard 1311 * against accidentally breaking the HTML. 1312 * 1313 * Because bookmarks allocate memory and require processing 1314 * for every applied update, they are limited and require 1315 * a name. They should not be created with programmatically-made 1316 * names, such as "li_{$index}" with some loop. As a general 1317 * rule they should only be created with string-literal names 1318 * like "start-of-section" or "last-paragraph". 1319 * 1320 * Bookmarks are a powerful tool to enable complicated behavior. 1321 * Consider double-checking that you need this tool if you are 1322 * reaching for it, as inappropriate use could lead to broken 1323 * HTML structure or unwanted processing overhead. 1324 * 1325 * @since 6.2.0 1326 * 1327 * @param string $name Identifies this particular bookmark. 1328 * @return bool Whether the bookmark was successfully created. 1329 */ 1330 public function set_bookmark( $name ): bool { 1331 // It only makes sense to set a bookmark if the parser has paused on a concrete token. 1332 if ( 1333 self::STATE_COMPLETE === $this->parser_state || 1334 self::STATE_INCOMPLETE_INPUT === $this->parser_state 1335 ) { 1336 return false; 1337 } 1338 1339 if ( ! array_key_exists( $name, $this->bookmarks ) && count( $this->bookmarks ) >= static::MAX_BOOKMARKS ) { 1340 _doing_it_wrong( 1341 __METHOD__, 1342 __( 'Too many bookmarks: cannot create any more.' ), 1343 '6.2.0' 1344 ); 1345 return false; 1346 } 1347 1348 $this->bookmarks[ $name ] = new WP_HTML_Span( $this->token_starts_at, $this->token_length ); 1349 1350 return true; 1351 } 1352 1353 1354 /** 1355 * Removes a bookmark that is no longer needed. 1356 * 1357 * Releasing a bookmark frees up the small 1358 * performance overhead it requires. 1359 * 1360 * @param string $name Name of the bookmark to remove. 1361 * @return bool Whether the bookmark already existed before removal. 1362 */ 1363 public function release_bookmark( $name ): bool { 1364 if ( ! array_key_exists( $name, $this->bookmarks ) ) { 1365 return false; 1366 } 1367 1368 unset( $this->bookmarks[ $name ] ); 1369 1370 return true; 1371 } 1372 1373 /** 1374 * Skips contents of generic rawtext elements. 1375 * 1376 * @since 6.3.2 1377 * 1378 * @see https://html.spec.whatwg.org/#generic-raw-text-element-parsing-algorithm 1379 * 1380 * @param string $tag_name The uppercase tag name which will close the RAWTEXT region. 1381 * @return bool Whether an end to the RAWTEXT region was found before the end of the document. 1382 */ 1383 private function skip_rawtext( string $tag_name ): bool { 1384 /* 1385 * These two functions distinguish themselves on whether character references are 1386 * decoded, and since functionality to read the inner markup isn't supported, it's 1387 * not necessary to implement these two functions separately. 1388 */ 1389 return $this->skip_rcdata( $tag_name ); 1390 } 1391 1392 /** 1393 * Skips contents of RCDATA elements, namely title and textarea tags. 1394 * 1395 * @since 6.2.0 1396 * 1397 * @see https://html.spec.whatwg.org/multipage/parsing.html#rcdata-state 1398 * 1399 * @param string $tag_name The uppercase tag name which will close the RCDATA region. 1400 * @return bool Whether an end to the RCDATA region was found before the end of the document. 1401 */ 1402 private function skip_rcdata( string $tag_name ): bool { 1403 $html = $this->html; 1404 $doc_length = strlen( $html ); 1405 $tag_length = strlen( $tag_name ); 1406 1407 $at = $this->bytes_already_parsed; 1408 1409 while ( false !== $at && $at < $doc_length ) { 1410 $at = strpos( $this->html, '</', $at ); 1411 $this->tag_name_starts_at = $at; 1412 1413 // Fail if there is no possible tag closer. 1414 if ( false === $at || ( $at + $tag_length ) >= $doc_length ) { 1415 return false; 1416 } 1417 1418 $at += 2; 1419 1420 /* 1421 * Find a case-insensitive match to the tag name. 1422 * 1423 * Because tag names are limited to US-ASCII there is no 1424 * need to perform any kind of Unicode normalization when 1425 * comparing; any character which could be impacted by such 1426 * normalization could not be part of a tag name. 1427 */ 1428 for ( $i = 0; $i < $tag_length; $i++ ) { 1429 $tag_char = $tag_name[ $i ]; 1430 $html_char = $html[ $at + $i ]; 1431 1432 if ( $html_char !== $tag_char && strtoupper( $html_char ) !== $tag_char ) { 1433 $at += $i; 1434 continue 2; 1435 } 1436 } 1437 1438 $at += $tag_length; 1439 $this->bytes_already_parsed = $at; 1440 1441 if ( $at >= strlen( $html ) ) { 1442 return false; 1443 } 1444 1445 /* 1446 * Ensure that the tag name terminates to avoid matching on 1447 * substrings of a longer tag name. For example, the sequence 1448 * "</textarearug" should not match for "</textarea" even 1449 * though "textarea" is found within the text. 1450 */ 1451 $c = $html[ $at ]; 1452 if ( ' ' !== $c && "\t" !== $c && "\r" !== $c && "\n" !== $c && '/' !== $c && '>' !== $c ) { 1453 continue; 1454 } 1455 1456 while ( $this->parse_next_attribute() ) { 1457 continue; 1458 } 1459 1460 $at = $this->bytes_already_parsed; 1461 if ( $at >= strlen( $this->html ) ) { 1462 return false; 1463 } 1464 1465 if ( '>' === $html[ $at ] ) { 1466 $this->bytes_already_parsed = $at + 1; 1467 return true; 1468 } 1469 1470 if ( $at + 1 >= strlen( $this->html ) ) { 1471 return false; 1472 } 1473 1474 if ( '/' === $html[ $at ] && '>' === $html[ $at + 1 ] ) { 1475 $this->bytes_already_parsed = $at + 2; 1476 return true; 1477 } 1478 } 1479 1480 return false; 1481 } 1482 1483 /** 1484 * Skips contents of script tags. 1485 * 1486 * @since 6.2.0 1487 * 1488 * @return bool Whether the script tag was closed before the end of the document. 1489 */ 1490 private function skip_script_data(): bool { 1491 $state = 'unescaped'; 1492 $html = $this->html; 1493 $doc_length = strlen( $html ); 1494 $at = $this->bytes_already_parsed; 1495 1496 while ( false !== $at && $at < $doc_length ) { 1497 $at += strcspn( $html, '-<', $at ); 1498 1499 /* 1500 * Optimization: Terminating a complete script element requires at least eight 1501 * additional bytes in the document. Some checks below may cause local escaped 1502 * state transitions when processing shorter strings, but those transitions are 1503 * irrelevant if the script tag is incomplete and the function must return false. 1504 * 1505 * This may need updating if those transitions become significant or exported from 1506 * this function in some way, such as when building safe methods to embed JavaScript 1507 * or data inside a SCRIPT element. 1508 * 1509 * $at may be here. 1510 * ↓ 1511 * ...</script> 1512 * ╰──┬───╯ 1513 * $at + 8 additional bytes are required for a non-false return value. 1514 * 1515 * This single check eliminates the need to check lengths for the shorter spans: 1516 * 1517 * $at may be here. 1518 * ↓ 1519 * <script><!-- --></script> 1520 * ├╯ 1521 * $at + 2 additional characters does not require a length check. 1522 * 1523 * The transition from "escaped" to "unescaped" is not relevant if the document ends: 1524 * 1525 * $at may be here. 1526 * ↓ 1527 * <script><!-- -->[[END-OF-DOCUMENT]] 1528 * ╰──┬───╯ 1529 * $at + 8 additional bytes is not satisfied, return false. 1530 */ 1531 if ( $at + 8 >= $doc_length ) { 1532 return false; 1533 } 1534 1535 /* 1536 * For all script states a "-->" transitions 1537 * back into the normal unescaped script mode, 1538 * even if that's the current state. 1539 */ 1540 if ( 1541 '-' === $html[ $at ] && 1542 '-' === $html[ $at + 1 ] && 1543 '>' === $html[ $at + 2 ] 1544 ) { 1545 $at += 3; 1546 $state = 'unescaped'; 1547 continue; 1548 } 1549 1550 /* 1551 * Everything of interest past here starts with "<". 1552 * Check this character and advance position regardless. 1553 */ 1554 if ( '<' !== $html[ $at++ ] ) { 1555 continue; 1556 } 1557 1558 /* 1559 * "<!--" only transitions from _unescaped_ to _escaped_. This byte sequence is only 1560 * significant in the _unescaped_ state and is ignored in any other state. 1561 */ 1562 if ( 1563 'unescaped' === $state && 1564 '!' === $html[ $at ] && 1565 '-' === $html[ $at + 1 ] && 1566 '-' === $html[ $at + 2 ] 1567 ) { 1568 $at += 3; 1569 1570 /* 1571 * The parser is ready to enter the _escaped_ state, but may remain in the 1572 * _unescaped_ state. This occurs when "<!--" is immediately followed by a 1573 * sequence of 0 or more "-" followed by ">". This is similar to abruptly closed 1574 * HTML comments like "<!-->" or "<!--->". 1575 * 1576 * Note that this check may advance the position significantly and requires a 1577 * length check to prevent bad offsets on inputs like `<script><!---------`. 1578 */ 1579 $at += strspn( $html, '-', $at ); 1580 if ( $at < $doc_length && '>' === $html[ $at ] ) { 1581 ++$at; 1582 continue; 1583 } 1584 1585 $state = 'escaped'; 1586 continue; 1587 } 1588 1589 if ( '/' === $html[ $at ] ) { 1590 $closer_potentially_starts_at = $at - 1; 1591 $is_closing = true; 1592 ++$at; 1593 } else { 1594 $is_closing = false; 1595 } 1596 1597 /* 1598 * At this point the only remaining state-changes occur with the 1599 * <script> and </script> tags; unless one of these appears next, 1600 * proceed scanning to the next potential token in the text. 1601 */ 1602 if ( ! ( 1603 ( 's' === $html[ $at ] || 'S' === $html[ $at ] ) && 1604 ( 'c' === $html[ $at + 1 ] || 'C' === $html[ $at + 1 ] ) && 1605 ( 'r' === $html[ $at + 2 ] || 'R' === $html[ $at + 2 ] ) && 1606 ( 'i' === $html[ $at + 3 ] || 'I' === $html[ $at + 3 ] ) && 1607 ( 'p' === $html[ $at + 4 ] || 'P' === $html[ $at + 4 ] ) && 1608 ( 't' === $html[ $at + 5 ] || 'T' === $html[ $at + 5 ] ) 1609 ) ) { 1610 ++$at; 1611 continue; 1612 } 1613 1614 /* 1615 * Ensure that the script tag terminates to avoid matching on 1616 * substrings of a non-match. For example, the sequence 1617 * "<script123" should not end a script region even though 1618 * "<script" is found within the text. 1619 */ 1620 $at += 6; 1621 $c = $html[ $at ]; 1622 if ( 1623 /** 1624 * These characters trigger state transitions of interest: 1625 * 1626 * - @see {https://html.spec.whatwg.org/multipage/parsing.html#script-data-end-tag-name-state} 1627 * - @see {https://html.spec.whatwg.org/multipage/parsing.html#script-data-escaped-end-tag-name-state} 1628 * - @see {https://html.spec.whatwg.org/multipage/parsing.html#script-data-double-escape-start-state} 1629 * - @see {https://html.spec.whatwg.org/multipage/parsing.html#script-data-double-escape-end-state} 1630 * 1631 * The "\r" character is not present in the above references. However, "\r" must be 1632 * treated the same as "\n". This is because the HTML Standard requires newline 1633 * normalization during preprocessing which applies this replacement. 1634 * 1635 * - @see https://html.spec.whatwg.org/multipage/parsing.html#preprocessing-the-input-stream 1636 * - @see https://infra.spec.whatwg.org/#normalize-newlines 1637 */ 1638 '>' !== $c && 1639 ' ' !== $c && 1640 "\n" !== $c && 1641 '/' !== $c && 1642 "\t" !== $c && 1643 "\f" !== $c && 1644 "\r" !== $c 1645 ) { 1646 continue; 1647 } 1648 1649 if ( 'escaped' === $state && ! $is_closing ) { 1650 $state = 'double-escaped'; 1651 continue; 1652 } 1653 1654 if ( 'double-escaped' === $state && $is_closing ) { 1655 $state = 'escaped'; 1656 continue; 1657 } 1658 1659 if ( $is_closing ) { 1660 $this->bytes_already_parsed = $closer_potentially_starts_at; 1661 $this->tag_name_starts_at = $closer_potentially_starts_at; 1662 if ( $this->bytes_already_parsed >= $doc_length ) { 1663 return false; 1664 } 1665 1666 while ( $this->parse_next_attribute() ) { 1667 continue; 1668 } 1669 1670 if ( $this->bytes_already_parsed >= $doc_length ) { 1671 return false; 1672 } 1673 1674 if ( '>' === $html[ $this->bytes_already_parsed ] ) { 1675 ++$this->bytes_already_parsed; 1676 return true; 1677 } 1678 } 1679 1680 ++$at; 1681 } 1682 1683 return false; 1684 } 1685 1686 /** 1687 * Parses the next tag. 1688 * 1689 * This will find and start parsing the next tag, including 1690 * the opening `<`, the potential closer `/`, and the tag 1691 * name. It does not parse the attributes or scan to the 1692 * closing `>`; these are left for other methods. 1693 * 1694 * @since 6.2.0 1695 * @since 6.2.1 Support abruptly-closed comments, invalid-tag-closer-comments, and empty elements. 1696 * 1697 * @return bool Whether a tag was found before the end of the document. 1698 */ 1699 private function parse_next_tag(): bool { 1700 $this->after_tag(); 1701 1702 $html = $this->html; 1703 $doc_length = strlen( $html ); 1704 $was_at = $this->bytes_already_parsed; 1705 $at = $was_at; 1706 1707 while ( $at < $doc_length ) { 1708 $at = strpos( $html, '<', $at ); 1709 if ( false === $at ) { 1710 break; 1711 } 1712 1713 if ( $at > $was_at ) { 1714 /* 1715 * A "<" normally starts a new HTML tag or syntax token, but in cases where the 1716 * following character can't produce a valid token, the "<" is instead treated 1717 * as plaintext and the parser should skip over it. This avoids a problem when 1718 * following earlier practices of typing emoji with text, e.g. "<3". This 1719 * should be a heart, not a tag. It's supposed to be rendered, not hidden. 1720 * 1721 * At this point the parser checks if this is one of those cases and if it is 1722 * will continue searching for the next "<" in search of a token boundary. 1723 * 1724 * @see https://html.spec.whatwg.org/#tag-open-state 1725 */ 1726 if ( 1 !== strspn( $html, '!/?abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ', $at + 1, 1 ) ) { 1727 ++$at; 1728 continue; 1729 } 1730 1731 $this->parser_state = self::STATE_TEXT_NODE; 1732 $this->token_starts_at = $was_at; 1733 $this->token_length = $at - $was_at; 1734 $this->text_starts_at = $was_at; 1735 $this->text_length = $this->token_length; 1736 $this->bytes_already_parsed = $at; 1737 return true; 1738 } 1739 1740 $this->token_starts_at = $at; 1741 1742 if ( $at + 1 < $doc_length && '/' === $this->html[ $at + 1 ] ) { 1743 $this->is_closing_tag = true; 1744 ++$at; 1745 } else { 1746 $this->is_closing_tag = false; 1747 } 1748 1749 /* 1750 * HTML tag names must start with [a-zA-Z] otherwise they are not tags. 1751 * For example, "<3" is rendered as text, not a tag opener. If at least 1752 * one letter follows the "<" then _it is_ a tag, but if the following 1753 * character is anything else it _is not a tag_. 1754 * 1755 * It's not uncommon to find non-tags starting with `<` in an HTML 1756 * document, so it's good for performance to make this pre-check before 1757 * continuing to attempt to parse a tag name. 1758 * 1759 * Reference: 1760 * * https://html.spec.whatwg.org/multipage/parsing.html#data-state 1761 * * https://html.spec.whatwg.org/multipage/parsing.html#tag-open-state 1762 */ 1763 $tag_name_prefix_length = strspn( $html, 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ', $at + 1 ); 1764 if ( $tag_name_prefix_length > 0 ) { 1765 ++$at; 1766 $this->parser_state = self::STATE_MATCHED_TAG; 1767 $this->tag_name_starts_at = $at; 1768 $this->tag_name_length = $tag_name_prefix_length + strcspn( $html, " \t\f\r\n/>", $at + $tag_name_prefix_length ); 1769 $this->bytes_already_parsed = $at + $this->tag_name_length; 1770 return true; 1771 } 1772 1773 /* 1774 * Abort if no tag is found before the end of 1775 * the document. There is nothing left to parse. 1776 */ 1777 if ( $at + 1 >= $doc_length ) { 1778 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 1779 1780 return false; 1781 } 1782 1783 /* 1784 * `<!` transitions to markup declaration open state 1785 * https://html.spec.whatwg.org/multipage/parsing.html#markup-declaration-open-state 1786 */ 1787 if ( ! $this->is_closing_tag && '!' === $html[ $at + 1 ] ) { 1788 /* 1789 * `<!--` transitions to a comment state – apply further comment rules. 1790 * https://html.spec.whatwg.org/multipage/parsing.html#tag-open-state 1791 */ 1792 if ( 0 === substr_compare( $html, '--', $at + 2, 2 ) ) { 1793 $closer_at = $at + 4; 1794 // If it's not possible to close the comment then there is nothing more to scan. 1795 if ( $doc_length <= $closer_at ) { 1796 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 1797 1798 return false; 1799 } 1800 1801 // Abruptly-closed empty comments are a sequence of dashes followed by `>`. 1802 $span_of_dashes = strspn( $html, '-', $closer_at ); 1803 if ( '>' === $html[ $closer_at + $span_of_dashes ] ) { 1804 /* 1805 * @todo When implementing `set_modifiable_text()` ensure that updates to this token 1806 * don't break the syntax for short comments, e.g. `<!--->`. Unlike other comment 1807 * and bogus comment syntax, these leave no clear insertion point for text and 1808 * they need to be modified specially in order to contain text. E.g. to store 1809 * `?` as the modifiable text, the `<!--->` needs to become `<!--?-->`, which 1810 * involves inserting an additional `-` into the token after the modifiable text. 1811 */ 1812 $this->parser_state = self::STATE_COMMENT; 1813 $this->comment_type = self::COMMENT_AS_ABRUPTLY_CLOSED_COMMENT; 1814 $this->token_length = $closer_at + $span_of_dashes + 1 - $this->token_starts_at; 1815 1816 // Only provide modifiable text if the token is long enough to contain it. 1817 if ( $span_of_dashes >= 2 ) { 1818 $this->comment_type = self::COMMENT_AS_HTML_COMMENT; 1819 $this->text_starts_at = $this->token_starts_at + 4; 1820 $this->text_length = $span_of_dashes - 2; 1821 } 1822 1823 $this->bytes_already_parsed = $closer_at + $span_of_dashes + 1; 1824 return true; 1825 } 1826 1827 /* 1828 * Comments may be closed by either a --> or an invalid --!>. 1829 * The first occurrence closes the comment. 1830 * 1831 * See https://html.spec.whatwg.org/#parse-error-incorrectly-closed-comment 1832 */ 1833 --$closer_at; // Pre-increment inside condition below reduces risk of accidental infinite looping. 1834 while ( ++$closer_at < $doc_length ) { 1835 $closer_at = strpos( $html, '--', $closer_at ); 1836 if ( false === $closer_at ) { 1837 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 1838 1839 return false; 1840 } 1841 1842 if ( $closer_at + 2 < $doc_length && '>' === $html[ $closer_at + 2 ] ) { 1843 $this->parser_state = self::STATE_COMMENT; 1844 $this->comment_type = self::COMMENT_AS_HTML_COMMENT; 1845 $this->token_length = $closer_at + 3 - $this->token_starts_at; 1846 $this->text_starts_at = $this->token_starts_at + 4; 1847 $this->text_length = $closer_at - $this->text_starts_at; 1848 $this->bytes_already_parsed = $closer_at + 3; 1849 return true; 1850 } 1851 1852 if ( 1853 $closer_at + 3 < $doc_length && 1854 '!' === $html[ $closer_at + 2 ] && 1855 '>' === $html[ $closer_at + 3 ] 1856 ) { 1857 $this->parser_state = self::STATE_COMMENT; 1858 $this->comment_type = self::COMMENT_AS_HTML_COMMENT; 1859 $this->token_length = $closer_at + 4 - $this->token_starts_at; 1860 $this->text_starts_at = $this->token_starts_at + 4; 1861 $this->text_length = $closer_at - $this->text_starts_at; 1862 $this->bytes_already_parsed = $closer_at + 4; 1863 return true; 1864 } 1865 } 1866 } 1867 1868 /* 1869 * `<!DOCTYPE` transitions to DOCTYPE state – skip to the nearest > 1870 * These are ASCII-case-insensitive. 1871 * https://html.spec.whatwg.org/multipage/parsing.html#tag-open-state 1872 */ 1873 if ( 1874 $doc_length > $at + 8 && 1875 ( 'D' === $html[ $at + 2 ] || 'd' === $html[ $at + 2 ] ) && 1876 ( 'O' === $html[ $at + 3 ] || 'o' === $html[ $at + 3 ] ) && 1877 ( 'C' === $html[ $at + 4 ] || 'c' === $html[ $at + 4 ] ) && 1878 ( 'T' === $html[ $at + 5 ] || 't' === $html[ $at + 5 ] ) && 1879 ( 'Y' === $html[ $at + 6 ] || 'y' === $html[ $at + 6 ] ) && 1880 ( 'P' === $html[ $at + 7 ] || 'p' === $html[ $at + 7 ] ) && 1881 ( 'E' === $html[ $at + 8 ] || 'e' === $html[ $at + 8 ] ) 1882 ) { 1883 $closer_at = strpos( $html, '>', $at + 9 ); 1884 if ( false === $closer_at ) { 1885 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 1886 1887 return false; 1888 } 1889 1890 $this->parser_state = self::STATE_DOCTYPE; 1891 $this->token_length = $closer_at + 1 - $this->token_starts_at; 1892 $this->text_starts_at = $this->token_starts_at + 9; 1893 $this->text_length = $closer_at - $this->text_starts_at; 1894 $this->bytes_already_parsed = $closer_at + 1; 1895 return true; 1896 } 1897 1898 if ( 1899 'html' !== $this->parsing_namespace && 1900 strlen( $html ) > $at + 8 && 1901 '[' === $html[ $at + 2 ] && 1902 'C' === $html[ $at + 3 ] && 1903 'D' === $html[ $at + 4 ] && 1904 'A' === $html[ $at + 5 ] && 1905 'T' === $html[ $at + 6 ] && 1906 'A' === $html[ $at + 7 ] && 1907 '[' === $html[ $at + 8 ] 1908 ) { 1909 $closer_at = strpos( $html, ']]>', $at + 9 ); 1910 if ( false === $closer_at ) { 1911 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 1912 1913 return false; 1914 } 1915 1916 $this->parser_state = self::STATE_CDATA_NODE; 1917 $this->text_starts_at = $at + 9; 1918 $this->text_length = $closer_at - $this->text_starts_at; 1919 $this->token_length = $closer_at + 3 - $this->token_starts_at; 1920 $this->bytes_already_parsed = $closer_at + 3; 1921 return true; 1922 } 1923 1924 /* 1925 * Anything else here is an incorrectly-opened comment and transitions 1926 * to the bogus comment state - skip to the nearest >. If no closer is 1927 * found then the HTML was truncated inside the markup declaration. 1928 */ 1929 $closer_at = strpos( $html, '>', $at + 1 ); 1930 if ( false === $closer_at ) { 1931 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 1932 1933 return false; 1934 } 1935 1936 $this->parser_state = self::STATE_COMMENT; 1937 $this->comment_type = self::COMMENT_AS_INVALID_HTML; 1938 $this->token_length = $closer_at + 1 - $this->token_starts_at; 1939 $this->text_starts_at = $this->token_starts_at + 2; 1940 $this->text_length = $closer_at - $this->text_starts_at; 1941 $this->bytes_already_parsed = $closer_at + 1; 1942 1943 /* 1944 * Identify nodes that would be CDATA if HTML had CDATA sections. 1945 * 1946 * This section must occur after identifying the bogus comment end 1947 * because in an HTML parser it will span to the nearest `>`, even 1948 * if there's no `]]>` as would be required in an XML document. It 1949 * is therefore not possible to parse a CDATA section containing 1950 * a `>` in the HTML syntax. 1951 * 1952 * Inside foreign elements there is a discrepancy between browsers 1953 * and the specification on this. 1954 * 1955 * @todo Track whether the Tag Processor is inside a foreign element 1956 * and require the proper closing `]]>` in those cases. 1957 */ 1958 if ( 1959 $this->token_length >= 10 && 1960 '[' === $html[ $this->token_starts_at + 2 ] && 1961 'C' === $html[ $this->token_starts_at + 3 ] && 1962 'D' === $html[ $this->token_starts_at + 4 ] && 1963 'A' === $html[ $this->token_starts_at + 5 ] && 1964 'T' === $html[ $this->token_starts_at + 6 ] && 1965 'A' === $html[ $this->token_starts_at + 7 ] && 1966 '[' === $html[ $this->token_starts_at + 8 ] && 1967 ']' === $html[ $closer_at - 1 ] && 1968 ']' === $html[ $closer_at - 2 ] 1969 ) { 1970 $this->parser_state = self::STATE_COMMENT; 1971 $this->comment_type = self::COMMENT_AS_CDATA_LOOKALIKE; 1972 $this->text_starts_at += 7; 1973 $this->text_length -= 9; 1974 } 1975 1976 return true; 1977 } 1978 1979 /* 1980 * </> is a missing end tag name, which is ignored. 1981 * 1982 * This was also known as the "presumptuous empty tag" 1983 * in early discussions as it was proposed to close 1984 * the nearest previous opening tag. 1985 * 1986 * See https://html.spec.whatwg.org/#parse-error-missing-end-tag-name 1987 */ 1988 if ( '>' === $html[ $at + 1 ] ) { 1989 // `<>` is interpreted as plaintext. 1990 if ( ! $this->is_closing_tag ) { 1991 ++$at; 1992 continue; 1993 } 1994 1995 $this->parser_state = self::STATE_PRESUMPTUOUS_TAG; 1996 $this->token_length = $at + 2 - $this->token_starts_at; 1997 $this->bytes_already_parsed = $at + 2; 1998 return true; 1999 } 2000 2001 /* 2002 * `<?` transitions to a bogus comment state – skip to the nearest > 2003 * See https://html.spec.whatwg.org/multipage/parsing.html#tag-open-state 2004 */ 2005 if ( ! $this->is_closing_tag && '?' === $html[ $at + 1 ] ) { 2006 $closer_at = strpos( $html, '>', $at + 2 ); 2007 if ( false === $closer_at ) { 2008 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 2009 2010 return false; 2011 } 2012 2013 $this->parser_state = self::STATE_COMMENT; 2014 $this->comment_type = self::COMMENT_AS_INVALID_HTML; 2015 $this->token_length = $closer_at + 1 - $this->token_starts_at; 2016 $this->text_starts_at = $this->token_starts_at + 2; 2017 $this->text_length = $closer_at - $this->text_starts_at; 2018 $this->bytes_already_parsed = $closer_at + 1; 2019 2020 /* 2021 * Identify a Processing Instruction node were HTML to have them. 2022 * 2023 * This section must occur after identifying the bogus comment end 2024 * because in an HTML parser it will span to the nearest `>`, even 2025 * if there's no `?>` as would be required in an XML document. It 2026 * is therefore not possible to parse a Processing Instruction node 2027 * containing a `>` in the HTML syntax. 2028 * 2029 * XML allows for more target names, but this code only identifies 2030 * those with ASCII-representable target names. This means that it 2031 * may identify some Processing Instruction nodes as bogus comments, 2032 * but it will not misinterpret the HTML structure. By limiting the 2033 * identification to these target names the Tag Processor can avoid 2034 * the need to start parsing UTF-8 sequences. 2035 * 2036 * > NameStartChar ::= ":" | [A-Z] | "_" | [a-z] | [#xC0-#xD6] | [#xD8-#xF6] | [#xF8-#x2FF] | 2037 * [#x370-#x37D] | [#x37F-#x1FFF] | [#x200C-#x200D] | [#x2070-#x218F] | 2038 * [#x2C00-#x2FEF] | [#x3001-#xD7FF] | [#xF900-#xFDCF] | [#xFDF0-#xFFFD] | 2039 * [#x10000-#xEFFFF] 2040 * > NameChar ::= NameStartChar | "-" | "." | [0-9] | #xB7 | [#x0300-#x036F] | [#x203F-#x2040] 2041 * 2042 * @todo Processing instruction nodes in SGML may contain any kind of markup. XML defines a 2043 * special case with `<?xml ... ?>` syntax, but the `?` is part of the bogus comment. 2044 * 2045 * @see https://www.w3.org/TR/2006/REC-xml11-20060816/#NT-PITarget 2046 */ 2047 if ( $this->token_length >= 5 && '?' === $html[ $closer_at - 1 ] ) { 2048 $comment_text = substr( $html, $this->token_starts_at + 2, $this->token_length - 4 ); 2049 $pi_target_length = strspn( $comment_text, 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ:_' ); 2050 2051 if ( 0 < $pi_target_length ) { 2052 $pi_target_length += strspn( $comment_text, 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789:_-.', $pi_target_length ); 2053 2054 $this->comment_type = self::COMMENT_AS_PI_NODE_LOOKALIKE; 2055 $this->tag_name_starts_at = $this->token_starts_at + 2; 2056 $this->tag_name_length = $pi_target_length; 2057 $this->text_starts_at += $pi_target_length; 2058 $this->text_length -= $pi_target_length + 1; 2059 } 2060 } 2061 2062 return true; 2063 } 2064 2065 /* 2066 * If a non-alpha starts the tag name in a tag closer it's a comment. 2067 * Find the first `>`, which closes the comment. 2068 * 2069 * This parser classifies these particular comments as special "funky comments" 2070 * which are made available for further processing. 2071 * 2072 * See https://html.spec.whatwg.org/#parse-error-invalid-first-character-of-tag-name 2073 */ 2074 if ( $this->is_closing_tag ) { 2075 // No chance of finding a closer. 2076 if ( $at + 3 > $doc_length ) { 2077 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 2078 2079 return false; 2080 } 2081 2082 $closer_at = strpos( $html, '>', $at + 2 ); 2083 if ( false === $closer_at ) { 2084 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 2085 2086 return false; 2087 } 2088 2089 $this->parser_state = self::STATE_FUNKY_COMMENT; 2090 $this->token_length = $closer_at + 1 - $this->token_starts_at; 2091 $this->text_starts_at = $this->token_starts_at + 2; 2092 $this->text_length = $closer_at - $this->text_starts_at; 2093 $this->bytes_already_parsed = $closer_at + 1; 2094 return true; 2095 } 2096 2097 ++$at; 2098 } 2099 2100 /* 2101 * This does not imply an incomplete parse; it indicates that there 2102 * can be nothing left in the document other than a #text node. 2103 */ 2104 $this->parser_state = self::STATE_TEXT_NODE; 2105 $this->token_starts_at = $was_at; 2106 $this->token_length = $doc_length - $was_at; 2107 $this->text_starts_at = $was_at; 2108 $this->text_length = $this->token_length; 2109 $this->bytes_already_parsed = $doc_length; 2110 return true; 2111 } 2112 2113 /** 2114 * Parses the next attribute. 2115 * 2116 * @since 6.2.0 2117 * 2118 * @return bool Whether an attribute was found before the end of the document. 2119 */ 2120 private function parse_next_attribute(): bool { 2121 $doc_length = strlen( $this->html ); 2122 2123 // Skip whitespace and slashes. 2124 $this->bytes_already_parsed += strspn( $this->html, " \t\f\r\n/", $this->bytes_already_parsed ); 2125 if ( $this->bytes_already_parsed >= $doc_length ) { 2126 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 2127 2128 return false; 2129 } 2130 2131 /* 2132 * Treat the equal sign as a part of the attribute 2133 * name if it is the first encountered byte. 2134 * 2135 * @see https://html.spec.whatwg.org/multipage/parsing.html#before-attribute-name-state 2136 */ 2137 $name_length = '=' === $this->html[ $this->bytes_already_parsed ] 2138 ? 1 + strcspn( $this->html, "=/> \t\f\r\n", $this->bytes_already_parsed + 1 ) 2139 : strcspn( $this->html, "=/> \t\f\r\n", $this->bytes_already_parsed ); 2140 2141 // No attribute, just tag closer. 2142 if ( 0 === $name_length || $this->bytes_already_parsed + $name_length >= $doc_length ) { 2143 return false; 2144 } 2145 2146 $attribute_start = $this->bytes_already_parsed; 2147 $attribute_name = substr( $this->html, $attribute_start, $name_length ); 2148 $this->bytes_already_parsed += $name_length; 2149 if ( $this->bytes_already_parsed >= $doc_length ) { 2150 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 2151 2152 return false; 2153 } 2154 2155 $this->skip_whitespace(); 2156 if ( $this->bytes_already_parsed >= $doc_length ) { 2157 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 2158 2159 return false; 2160 } 2161 2162 $has_value = '=' === $this->html[ $this->bytes_already_parsed ]; 2163 if ( $has_value ) { 2164 ++$this->bytes_already_parsed; 2165 $this->skip_whitespace(); 2166 if ( $this->bytes_already_parsed >= $doc_length ) { 2167 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 2168 2169 return false; 2170 } 2171 2172 switch ( $this->html[ $this->bytes_already_parsed ] ) { 2173 case "'": 2174 case '"': 2175 $quote = $this->html[ $this->bytes_already_parsed ]; 2176 $value_start = $this->bytes_already_parsed + 1; 2177 $end_quote_at = strpos( $this->html, $quote, $value_start ); 2178 $end_quote_at = false === $end_quote_at ? $doc_length : $end_quote_at; 2179 $value_length = $end_quote_at - $value_start; 2180 $attribute_end = $end_quote_at + 1; 2181 $this->bytes_already_parsed = $attribute_end; 2182 break; 2183 2184 default: 2185 $value_start = $this->bytes_already_parsed; 2186 $value_length = strcspn( $this->html, "> \t\f\r\n", $value_start ); 2187 $attribute_end = $value_start + $value_length; 2188 $this->bytes_already_parsed = $attribute_end; 2189 } 2190 } else { 2191 $value_start = $this->bytes_already_parsed; 2192 $value_length = 0; 2193 $attribute_end = $attribute_start + $name_length; 2194 } 2195 2196 if ( $attribute_end >= $doc_length ) { 2197 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 2198 2199 return false; 2200 } 2201 2202 if ( $this->is_closing_tag ) { 2203 return true; 2204 } 2205 2206 /* 2207 * > There must never be two or more attributes on 2208 * > the same start tag whose names are an ASCII 2209 * > case-insensitive match for each other. 2210 * - HTML 5 spec 2211 * 2212 * @see https://html.spec.whatwg.org/multipage/syntax.html#attributes-2:ascii-case-insensitive 2213 */ 2214 $comparable_name = strtolower( $attribute_name ); 2215 2216 // If an attribute is listed many times, only use the first declaration and ignore the rest. 2217 if ( ! isset( $this->attributes[ $comparable_name ] ) ) { 2218 $this->attributes[ $comparable_name ] = new WP_HTML_Attribute_Token( 2219 $attribute_name, 2220 $value_start, 2221 $value_length, 2222 $attribute_start, 2223 $attribute_end - $attribute_start, 2224 ! $has_value 2225 ); 2226 2227 return true; 2228 } 2229 2230 /* 2231 * Track the duplicate attributes so if we remove it, all disappear together. 2232 * 2233 * While `$this->duplicated_attributes` could always be stored as an `array()`, 2234 * which would simplify the logic here, storing a `null` and only allocating 2235 * an array when encountering duplicates avoids needless allocations in the 2236 * normative case of parsing tags with no duplicate attributes. 2237 */ 2238 $duplicate_span = new WP_HTML_Span( $attribute_start, $attribute_end - $attribute_start ); 2239 if ( null === $this->duplicate_attributes ) { 2240 $this->duplicate_attributes = array( $comparable_name => array( $duplicate_span ) ); 2241 } elseif ( ! isset( $this->duplicate_attributes[ $comparable_name ] ) ) { 2242 $this->duplicate_attributes[ $comparable_name ] = array( $duplicate_span ); 2243 } else { 2244 $this->duplicate_attributes[ $comparable_name ][] = $duplicate_span; 2245 } 2246 2247 return true; 2248 } 2249 2250 /** 2251 * Move the internal cursor past any immediate successive whitespace. 2252 * 2253 * @since 6.2.0 2254 */ 2255 private function skip_whitespace(): void { 2256 $this->bytes_already_parsed += strspn( $this->html, " \t\f\r\n", $this->bytes_already_parsed ); 2257 } 2258 2259 /** 2260 * Applies attribute updates and cleans up once a tag is fully parsed. 2261 * 2262 * @since 6.2.0 2263 */ 2264 private function after_tag(): void { 2265 /* 2266 * There could be lexical updates enqueued for an attribute that 2267 * also exists on the next tag. In order to avoid conflating the 2268 * attributes across the two tags, lexical updates with names 2269 * need to be flushed to raw lexical updates. 2270 */ 2271 $this->class_name_updates_to_attributes_updates(); 2272 2273 /* 2274 * Purge updates if there are too many. The actual count isn't 2275 * scientific, but a few values from 100 to a few thousand were 2276 * tests to find a practically-useful limit. 2277 * 2278 * If the update queue grows too big, then the Tag Processor 2279 * will spend more time iterating through them and lose the 2280 * efficiency gains of deferring applying them. 2281 */ 2282 if ( 1000 < count( $this->lexical_updates ) ) { 2283 $this->get_updated_html(); 2284 } 2285 2286 foreach ( $this->lexical_updates as $name => $update ) { 2287 /* 2288 * Any updates appearing after the cursor should be applied 2289 * before proceeding, otherwise they may be overlooked. 2290 */ 2291 if ( $update->start >= $this->bytes_already_parsed ) { 2292 $this->get_updated_html(); 2293 break; 2294 } 2295 2296 if ( is_int( $name ) ) { 2297 continue; 2298 } 2299 2300 $this->lexical_updates[] = $update; 2301 unset( $this->lexical_updates[ $name ] ); 2302 } 2303 2304 $this->token_starts_at = null; 2305 $this->token_length = null; 2306 $this->tag_name_starts_at = null; 2307 $this->tag_name_length = null; 2308 $this->text_starts_at = 0; 2309 $this->text_length = 0; 2310 $this->is_closing_tag = null; 2311 $this->attributes = array(); 2312 $this->comment_type = null; 2313 $this->text_node_classification = self::TEXT_IS_GENERIC; 2314 $this->duplicate_attributes = null; 2315 } 2316 2317 /** 2318 * Converts class name updates into tag attributes updates 2319 * (they are accumulated in different data formats for performance). 2320 * 2321 * @since 6.2.0 2322 * 2323 * @see WP_HTML_Tag_Processor::$lexical_updates 2324 * @see WP_HTML_Tag_Processor::$classname_updates 2325 */ 2326 private function class_name_updates_to_attributes_updates(): void { 2327 if ( count( $this->classname_updates ) === 0 ) { 2328 return; 2329 } 2330 2331 $existing_class = $this->get_enqueued_attribute_value( 'class' ); 2332 if ( null === $existing_class || true === $existing_class ) { 2333 $existing_class = ''; 2334 } 2335 2336 if ( false === $existing_class && isset( $this->attributes['class'] ) ) { 2337 $existing_class = substr( 2338 $this->html, 2339 $this->attributes['class']->value_starts_at, 2340 $this->attributes['class']->value_length 2341 ); 2342 } 2343 2344 if ( false === $existing_class ) { 2345 $existing_class = ''; 2346 } 2347 2348 /** 2349 * Updated "class" attribute value. 2350 * 2351 * This is incrementally built while scanning through the existing class 2352 * attribute, skipping removed classes on the way, and then appending 2353 * added classes at the end. Only when finished processing will the 2354 * value contain the final new value. 2355 2356 * @var string $class 2357 */ 2358 $class = ''; 2359 2360 /** 2361 * Tracks the cursor position in the existing 2362 * class attribute value while parsing. 2363 * 2364 * @var int $at 2365 */ 2366 $at = 0; 2367 2368 /** 2369 * Indicates if there's any need to modify the existing class attribute. 2370 * 2371 * If a call to `add_class()` and `remove_class()` wouldn't impact 2372 * the `class` attribute value then there's no need to rebuild it. 2373 * For example, when adding a class that's already present or 2374 * removing one that isn't. 2375 * 2376 * This flag enables a performance optimization when none of the enqueued 2377 * class updates would impact the `class` attribute; namely, that the 2378 * processor can continue without modifying the input document, as if 2379 * none of the `add_class()` or `remove_class()` calls had been made. 2380 * 2381 * This flag is set upon the first change that requires a string update. 2382 * 2383 * @var bool $modified 2384 */ 2385 $modified = false; 2386 2387 $seen = array(); 2388 $to_remove = array(); 2389 $is_quirks = self::QUIRKS_MODE === $this->compat_mode; 2390 if ( $is_quirks ) { 2391 foreach ( $this->classname_updates as $updated_name => $action ) { 2392 if ( self::REMOVE_CLASS === $action ) { 2393 $to_remove[] = strtolower( $updated_name ); 2394 } 2395 } 2396 } else { 2397 foreach ( $this->classname_updates as $updated_name => $action ) { 2398 if ( self::REMOVE_CLASS === $action ) { 2399 $to_remove[] = $updated_name; 2400 } 2401 } 2402 } 2403 2404 // Remove unwanted classes by only copying the new ones. 2405 $existing_class_length = strlen( $existing_class ); 2406 while ( $at < $existing_class_length ) { 2407 // Skip to the first non-whitespace character. 2408 $ws_at = $at; 2409 $ws_length = strspn( $existing_class, " \t\f\r\n", $ws_at ); 2410 $at += $ws_length; 2411 2412 // Capture the class name – it's everything until the next whitespace. 2413 $name_length = strcspn( $existing_class, " \t\f\r\n", $at ); 2414 if ( 0 === $name_length ) { 2415 // If no more class names are found then that's the end. 2416 break; 2417 } 2418 2419 $name = substr( $existing_class, $at, $name_length ); 2420 $comparable_class_name = $is_quirks ? strtolower( $name ) : $name; 2421 $at += $name_length; 2422 2423 // If this class is marked for removal, remove it and move on to the next one. 2424 if ( in_array( $comparable_class_name, $to_remove, true ) ) { 2425 $modified = true; 2426 continue; 2427 } 2428 2429 // If a class has already been seen then skip it; it should not be added twice. 2430 if ( in_array( $comparable_class_name, $seen, true ) ) { 2431 continue; 2432 } 2433 2434 $seen[] = $comparable_class_name; 2435 2436 /* 2437 * Otherwise, append it to the new "class" attribute value. 2438 * 2439 * There are options for handling whitespace between tags. 2440 * Preserving the existing whitespace produces fewer changes 2441 * to the HTML content and should clarify the before/after 2442 * content when debugging the modified output. 2443 * 2444 * This approach contrasts normalizing the inter-class 2445 * whitespace to a single space, which might appear cleaner 2446 * in the output HTML but produce a noisier change. 2447 */ 2448 if ( '' !== $class ) { 2449 $class .= substr( $existing_class, $ws_at, $ws_length ); 2450 } 2451 $class .= $name; 2452 } 2453 2454 // Add new classes by appending those which haven't already been seen. 2455 foreach ( $this->classname_updates as $name => $operation ) { 2456 $comparable_name = $is_quirks ? strtolower( $name ) : $name; 2457 if ( self::ADD_CLASS === $operation && ! in_array( $comparable_name, $seen, true ) ) { 2458 $modified = true; 2459 2460 $class .= strlen( $class ) > 0 ? ' ' : ''; 2461 $class .= $name; 2462 } 2463 } 2464 2465 $this->classname_updates = array(); 2466 if ( ! $modified ) { 2467 return; 2468 } 2469 2470 if ( strlen( $class ) > 0 ) { 2471 $this->set_attribute( 'class', $class ); 2472 } else { 2473 $this->remove_attribute( 'class' ); 2474 } 2475 } 2476 2477 /** 2478 * Applies attribute updates to HTML document. 2479 * 2480 * @since 6.2.0 2481 * @since 6.2.1 Accumulates shift for internal cursor and passed pointer. 2482 * @since 6.3.0 Invalidate any bookmarks whose targets are overwritten. 2483 * 2484 * @param int $shift_this_point Accumulate and return shift for this position. 2485 * @return int How many bytes the given pointer moved in response to the updates. 2486 */ 2487 private function apply_attributes_updates( int $shift_this_point ): int { 2488 if ( ! count( $this->lexical_updates ) ) { 2489 return 0; 2490 } 2491 2492 $accumulated_shift_for_given_point = 0; 2493 2494 /* 2495 * Attribute updates can be enqueued in any order but updates 2496 * to the document must occur in lexical order; that is, each 2497 * replacement must be made before all others which follow it 2498 * at later string indices in the input document. 2499 * 2500 * Sorting avoid making out-of-order replacements which 2501 * can lead to mangled output, partially-duplicated 2502 * attributes, and overwritten attributes. 2503 */ 2504 usort( $this->lexical_updates, array( self::class, 'sort_start_ascending' ) ); 2505 2506 $bytes_already_copied = 0; 2507 $output_buffer = ''; 2508 foreach ( $this->lexical_updates as $diff ) { 2509 $shift = strlen( $diff->text ) - $diff->length; 2510 2511 // Adjust the cursor position by however much an update affects it. 2512 if ( $diff->start < $this->bytes_already_parsed ) { 2513 $this->bytes_already_parsed += $shift; 2514 } 2515 2516 // Accumulate shift of the given pointer within this function call. 2517 if ( $diff->start < $shift_this_point ) { 2518 $accumulated_shift_for_given_point += $shift; 2519 } 2520 2521 $output_buffer .= substr( $this->html, $bytes_already_copied, $diff->start - $bytes_already_copied ); 2522 $output_buffer .= $diff->text; 2523 $bytes_already_copied = $diff->start + $diff->length; 2524 } 2525 2526 $this->html = $output_buffer . substr( $this->html, $bytes_already_copied ); 2527 2528 /* 2529 * Adjust bookmark locations to account for how the text 2530 * replacements adjust offsets in the input document. 2531 */ 2532 foreach ( $this->bookmarks as $bookmark_name => $bookmark ) { 2533 $bookmark_end = $bookmark->start + $bookmark->length; 2534 2535 /* 2536 * Each lexical update which appears before the bookmark's endpoints 2537 * might shift the offsets for those endpoints. Loop through each change 2538 * and accumulate the total shift for each bookmark, then apply that 2539 * shift after tallying the full delta. 2540 */ 2541 $head_delta = 0; 2542 $tail_delta = 0; 2543 2544 foreach ( $this->lexical_updates as $diff ) { 2545 $diff_end = $diff->start + $diff->length; 2546 2547 if ( $bookmark->start < $diff->start && $bookmark_end < $diff->start ) { 2548 break; 2549 } 2550 2551 if ( $bookmark->start >= $diff->start && $bookmark_end < $diff_end ) { 2552 $this->release_bookmark( $bookmark_name ); 2553 continue 2; 2554 } 2555 2556 $delta = strlen( $diff->text ) - $diff->length; 2557 2558 if ( $bookmark->start >= $diff->start ) { 2559 $head_delta += $delta; 2560 } 2561 2562 if ( $bookmark_end >= $diff_end ) { 2563 $tail_delta += $delta; 2564 } 2565 } 2566 2567 $bookmark->start += $head_delta; 2568 $bookmark->length += $tail_delta - $head_delta; 2569 } 2570 2571 $this->lexical_updates = array(); 2572 2573 return $accumulated_shift_for_given_point; 2574 } 2575 2576 /** 2577 * Checks whether a bookmark with the given name exists. 2578 * 2579 * @since 6.3.0 2580 * 2581 * @param string $bookmark_name Name to identify a bookmark that potentially exists. 2582 * @return bool Whether that bookmark exists. 2583 */ 2584 public function has_bookmark( $bookmark_name ): bool { 2585 return array_key_exists( $bookmark_name, $this->bookmarks ); 2586 } 2587 2588 /** 2589 * Move the internal cursor in the Tag Processor to a given bookmark's location. 2590 * 2591 * In order to prevent accidental infinite loops, there's a 2592 * maximum limit on the number of times seek() can be called. 2593 * 2594 * @since 6.2.0 2595 * 2596 * @param string $bookmark_name Jump to the place in the document identified by this bookmark name. 2597 * @return bool Whether the internal cursor was successfully moved to the bookmark's location. 2598 */ 2599 public function seek( $bookmark_name ): bool { 2600 if ( ! array_key_exists( $bookmark_name, $this->bookmarks ) ) { 2601 _doing_it_wrong( 2602 __METHOD__, 2603 __( 'Unknown bookmark name.' ), 2604 '6.2.0' 2605 ); 2606 return false; 2607 } 2608 2609 $existing_bookmark = $this->bookmarks[ $bookmark_name ]; 2610 2611 if ( 2612 $this->token_starts_at === $existing_bookmark->start && 2613 $this->token_length === $existing_bookmark->length 2614 ) { 2615 return true; 2616 } 2617 2618 if ( ++$this->seek_count > static::MAX_SEEK_OPS ) { 2619 _doing_it_wrong( 2620 __METHOD__, 2621 __( 'Too many calls to seek() - this can lead to performance issues.' ), 2622 '6.2.0' 2623 ); 2624 return false; 2625 } 2626 2627 // Flush out any pending updates to the document. 2628 $this->get_updated_html(); 2629 2630 // Point this tag processor before the sought tag opener and consume it. 2631 $this->bytes_already_parsed = $this->bookmarks[ $bookmark_name ]->start; 2632 $this->parser_state = self::STATE_READY; 2633 return $this->next_token(); 2634 } 2635 2636 /** 2637 * Compare two WP_HTML_Text_Replacement objects. 2638 * 2639 * @since 6.2.0 2640 * 2641 * @param WP_HTML_Text_Replacement $a First attribute update. 2642 * @param WP_HTML_Text_Replacement $b Second attribute update. 2643 * @return int Comparison value for string order. 2644 */ 2645 private static function sort_start_ascending( WP_HTML_Text_Replacement $a, WP_HTML_Text_Replacement $b ): int { 2646 $by_start = $a->start - $b->start; 2647 if ( 0 !== $by_start ) { 2648 return $by_start; 2649 } 2650 2651 $by_text = isset( $a->text, $b->text ) ? strcmp( $a->text, $b->text ) : 0; 2652 if ( 0 !== $by_text ) { 2653 return $by_text; 2654 } 2655 2656 /* 2657 * This code should be unreachable, because it implies the two replacements 2658 * start at the same location and contain the same text. 2659 */ 2660 return $a->length - $b->length; 2661 } 2662 2663 /** 2664 * Return the enqueued value for a given attribute, if one exists. 2665 * 2666 * Enqueued updates can take different data types: 2667 * - If an update is enqueued and is boolean, the return will be `true` 2668 * - If an update is otherwise enqueued, the return will be the string value of that update. 2669 * - If an attribute is enqueued to be removed, the return will be `null` to indicate that. 2670 * - If no updates are enqueued, the return will be `false` to differentiate from "removed." 2671 * 2672 * @since 6.2.0 2673 * 2674 * @param string $comparable_name The attribute name in its comparable form. 2675 * @return string|boolean|null Value of enqueued update if present, otherwise false. 2676 */ 2677 private function get_enqueued_attribute_value( string $comparable_name ) { 2678 if ( self::STATE_MATCHED_TAG !== $this->parser_state ) { 2679 return false; 2680 } 2681 2682 if ( ! isset( $this->lexical_updates[ $comparable_name ] ) ) { 2683 return false; 2684 } 2685 2686 $enqueued_text = $this->lexical_updates[ $comparable_name ]->text; 2687 2688 // Removed attributes erase the entire span. 2689 if ( '' === $enqueued_text ) { 2690 return null; 2691 } 2692 2693 /* 2694 * Boolean attribute updates are just the attribute name without a corresponding value. 2695 * 2696 * This value might differ from the given comparable name in that there could be leading 2697 * or trailing whitespace, and that the casing follows the name given in `set_attribute`. 2698 * 2699 * Example: 2700 * 2701 * $p->set_attribute( 'data-TEST-id', 'update' ); 2702 * 'update' === $p->get_enqueued_attribute_value( 'data-test-id' ); 2703 * 2704 * Detect this difference based on the absence of the `=`, which _must_ exist in any 2705 * attribute containing a value, e.g. `<input type="text" enabled />`. 2706 * ¹ ² 2707 * 1. Attribute with a string value. 2708 * 2. Boolean attribute whose value is `true`. 2709 */ 2710 $equals_at = strpos( $enqueued_text, '=' ); 2711 if ( false === $equals_at ) { 2712 return true; 2713 } 2714 2715 /* 2716 * Finally, a normal update's value will appear after the `=` and 2717 * be double-quoted, as performed incidentally by `set_attribute`. 2718 * 2719 * e.g. `type="text"` 2720 * ¹² ³ 2721 * 1. Equals is here. 2722 * 2. Double-quoting starts one after the equals sign. 2723 * 3. Double-quoting ends at the last character in the update. 2724 */ 2725 $enqueued_value = substr( $enqueued_text, $equals_at + 2, -1 ); 2726 return WP_HTML_Decoder::decode_attribute( $enqueued_value ); 2727 } 2728 2729 /** 2730 * Returns the value of a requested attribute from a matched tag opener if that attribute exists. 2731 * 2732 * Example: 2733 * 2734 * $p = new WP_HTML_Tag_Processor( '<div enabled class="test" data-test-id="14">Test</div>' ); 2735 * $p->next_tag( array( 'class_name' => 'test' ) ) === true; 2736 * $p->get_attribute( 'data-test-id' ) === '14'; 2737 * $p->get_attribute( 'enabled' ) === true; 2738 * $p->get_attribute( 'aria-label' ) === null; 2739 * 2740 * $p->next_tag() === false; 2741 * $p->get_attribute( 'class' ) === null; 2742 * 2743 * @since 6.2.0 2744 * 2745 * @param string $name Name of attribute whose value is requested. 2746 * @return string|true|null Value of attribute or `null` if not available. Boolean attributes return `true`. 2747 */ 2748 public function get_attribute( $name ) { 2749 if ( self::STATE_MATCHED_TAG !== $this->parser_state ) { 2750 return null; 2751 } 2752 2753 $comparable = strtolower( $name ); 2754 2755 /* 2756 * For every attribute other than `class` it's possible to perform a quick check if 2757 * there's an enqueued lexical update whose value takes priority over what's found in 2758 * the input document. 2759 * 2760 * The `class` attribute is special though because of the exposed helpers `add_class` 2761 * and `remove_class`. These form a builder for the `class` attribute, so an additional 2762 * check for enqueued class changes is required in addition to the check for any enqueued 2763 * attribute values. If any exist, those enqueued class changes must first be flushed out 2764 * into an attribute value update. 2765 */ 2766 if ( 'class' === $name ) { 2767 $this->class_name_updates_to_attributes_updates(); 2768 } 2769 2770 // Return any enqueued attribute value updates if they exist. 2771 $enqueued_value = $this->get_enqueued_attribute_value( $comparable ); 2772 if ( false !== $enqueued_value ) { 2773 return $enqueued_value; 2774 } 2775 2776 if ( ! isset( $this->attributes[ $comparable ] ) ) { 2777 return null; 2778 } 2779 2780 $attribute = $this->attributes[ $comparable ]; 2781 2782 /* 2783 * This flag distinguishes an attribute with no value 2784 * from an attribute with an empty string value. For 2785 * unquoted attributes this could look very similar. 2786 * It refers to whether an `=` follows the name. 2787 * 2788 * e.g. <div boolean-attribute empty-attribute=></div> 2789 * ¹ ² 2790 * 1. Attribute `boolean-attribute` is `true`. 2791 * 2. Attribute `empty-attribute` is `""`. 2792 */ 2793 if ( true === $attribute->is_true ) { 2794 return true; 2795 } 2796 2797 $raw_value = substr( $this->html, $attribute->value_starts_at, $attribute->value_length ); 2798 2799 return WP_HTML_Decoder::decode_attribute( $raw_value ); 2800 } 2801 2802 /** 2803 * Gets lowercase names of all attributes matching a given prefix in the current tag. 2804 * 2805 * Note that matching is case-insensitive. This is in accordance with the spec: 2806 * 2807 * > There must never be two or more attributes on 2808 * > the same start tag whose names are an ASCII 2809 * > case-insensitive match for each other. 2810 * - HTML 5 spec 2811 * 2812 * Example: 2813 * 2814 * $p = new WP_HTML_Tag_Processor( '<div data-ENABLED class="test" DATA-test-id="14">Test</div>' ); 2815 * $p->next_tag( array( 'class_name' => 'test' ) ) === true; 2816 * $p->get_attribute_names_with_prefix( 'data-' ) === array( 'data-enabled', 'data-test-id' ); 2817 * 2818 * $p->next_tag() === false; 2819 * $p->get_attribute_names_with_prefix( 'data-' ) === null; 2820 * 2821 * @since 6.2.0 2822 * 2823 * @see https://html.spec.whatwg.org/multipage/syntax.html#attributes-2:ascii-case-insensitive 2824 * 2825 * @param string $prefix Prefix of requested attribute names. 2826 * @return array|null List of attribute names, or `null` when no tag opener is matched. 2827 */ 2828 public function get_attribute_names_with_prefix( $prefix ): ?array { 2829 if ( 2830 self::STATE_MATCHED_TAG !== $this->parser_state || 2831 $this->is_closing_tag 2832 ) { 2833 return null; 2834 } 2835 2836 $comparable = strtolower( $prefix ); 2837 2838 $matches = array(); 2839 foreach ( array_keys( $this->attributes ) as $attr_name ) { 2840 if ( str_starts_with( $attr_name, $comparable ) ) { 2841 $matches[] = $attr_name; 2842 } 2843 } 2844 return $matches; 2845 } 2846 2847 /** 2848 * Returns the namespace of the matched token. 2849 * 2850 * @since 6.7.0 2851 * 2852 * @return string One of 'html', 'math', or 'svg'. 2853 */ 2854 public function get_namespace(): string { 2855 return $this->parsing_namespace; 2856 } 2857 2858 /** 2859 * Returns the uppercase name of the matched tag. 2860 * 2861 * Example: 2862 * 2863 * $p = new WP_HTML_Tag_Processor( '<div class="test">Test</div>' ); 2864 * $p->next_tag() === true; 2865 * $p->get_tag() === 'DIV'; 2866 * 2867 * $p->next_tag() === false; 2868 * $p->get_tag() === null; 2869 * 2870 * @since 6.2.0 2871 * 2872 * @return string|null Name of currently matched tag in input HTML, or `null` if none found. 2873 */ 2874 public function get_tag(): ?string { 2875 if ( null === $this->tag_name_starts_at ) { 2876 return null; 2877 } 2878 2879 $tag_name = substr( $this->html, $this->tag_name_starts_at, $this->tag_name_length ); 2880 2881 if ( self::STATE_MATCHED_TAG === $this->parser_state ) { 2882 return strtoupper( $tag_name ); 2883 } 2884 2885 if ( 2886 self::STATE_COMMENT === $this->parser_state && 2887 self::COMMENT_AS_PI_NODE_LOOKALIKE === $this->get_comment_type() 2888 ) { 2889 return $tag_name; 2890 } 2891 2892 return null; 2893 } 2894 2895 /** 2896 * Returns the adjusted tag name for a given token, taking into 2897 * account the current parsing context, whether HTML, SVG, or MathML. 2898 * 2899 * @since 6.7.0 2900 * 2901 * @return string|null Name of current tag name. 2902 */ 2903 public function get_qualified_tag_name(): ?string { 2904 $tag_name = $this->get_tag(); 2905 if ( null === $tag_name ) { 2906 return null; 2907 } 2908 2909 if ( 'html' === $this->get_namespace() ) { 2910 return $tag_name; 2911 } 2912 2913 $lower_tag_name = strtolower( $tag_name ); 2914 if ( 'math' === $this->get_namespace() ) { 2915 return $lower_tag_name; 2916 } 2917 2918 if ( 'svg' === $this->get_namespace() ) { 2919 switch ( $lower_tag_name ) { 2920 case 'altglyph': 2921 return 'altGlyph'; 2922 2923 case 'altglyphdef': 2924 return 'altGlyphDef'; 2925 2926 case 'altglyphitem': 2927 return 'altGlyphItem'; 2928 2929 case 'animatecolor': 2930 return 'animateColor'; 2931 2932 case 'animatemotion': 2933 return 'animateMotion'; 2934 2935 case 'animatetransform': 2936 return 'animateTransform'; 2937 2938 case 'clippath': 2939 return 'clipPath'; 2940 2941 case 'feblend': 2942 return 'feBlend'; 2943 2944 case 'fecolormatrix': 2945 return 'feColorMatrix'; 2946 2947 case 'fecomponenttransfer': 2948 return 'feComponentTransfer'; 2949 2950 case 'fecomposite': 2951 return 'feComposite'; 2952 2953 case 'feconvolvematrix': 2954 return 'feConvolveMatrix'; 2955 2956 case 'fediffuselighting': 2957 return 'feDiffuseLighting'; 2958 2959 case 'fedisplacementmap': 2960 return 'feDisplacementMap'; 2961 2962 case 'fedistantlight': 2963 return 'feDistantLight'; 2964 2965 case 'fedropshadow': 2966 return 'feDropShadow'; 2967 2968 case 'feflood': 2969 return 'feFlood'; 2970 2971 case 'fefunca': 2972 return 'feFuncA'; 2973 2974 case 'fefuncb': 2975 return 'feFuncB'; 2976 2977 case 'fefuncg': 2978 return 'feFuncG'; 2979 2980 case 'fefuncr': 2981 return 'feFuncR'; 2982 2983 case 'fegaussianblur': 2984 return 'feGaussianBlur'; 2985 2986 case 'feimage': 2987 return 'feImage'; 2988 2989 case 'femerge': 2990 return 'feMerge'; 2991 2992 case 'femergenode': 2993 return 'feMergeNode'; 2994 2995 case 'femorphology': 2996 return 'feMorphology'; 2997 2998 case 'feoffset': 2999 return 'feOffset'; 3000 3001 case 'fepointlight': 3002 return 'fePointLight'; 3003 3004 case 'fespecularlighting': 3005 return 'feSpecularLighting'; 3006 3007 case 'fespotlight': 3008 return 'feSpotLight'; 3009 3010 case 'fetile': 3011 return 'feTile'; 3012 3013 case 'feturbulence': 3014 return 'feTurbulence'; 3015 3016 case 'foreignobject': 3017 return 'foreignObject'; 3018 3019 case 'glyphref': 3020 return 'glyphRef'; 3021 3022 case 'lineargradient': 3023 return 'linearGradient'; 3024 3025 case 'radialgradient': 3026 return 'radialGradient'; 3027 3028 case 'textpath': 3029 return 'textPath'; 3030 3031 default: 3032 return $lower_tag_name; 3033 } 3034 } 3035 3036 // This unnecessary return prevents tools from inaccurately reporting type errors. 3037 return $tag_name; 3038 } 3039 3040 /** 3041 * Returns the adjusted attribute name for a given attribute, taking into 3042 * account the current parsing context, whether HTML, SVG, or MathML. 3043 * 3044 * @since 6.7.0 3045 * 3046 * @param string $attribute_name Which attribute to adjust. 3047 * 3048 * @return string|null 3049 */ 3050 public function get_qualified_attribute_name( $attribute_name ): ?string { 3051 if ( self::STATE_MATCHED_TAG !== $this->parser_state ) { 3052 return null; 3053 } 3054 3055 $namespace = $this->get_namespace(); 3056 $lower_name = strtolower( $attribute_name ); 3057 3058 if ( 'math' === $namespace && 'definitionurl' === $lower_name ) { 3059 return 'definitionURL'; 3060 } 3061 3062 if ( 'svg' === $this->get_namespace() ) { 3063 switch ( $lower_name ) { 3064 case 'attributename': 3065 return 'attributeName'; 3066 3067 case 'attributetype': 3068 return 'attributeType'; 3069 3070 case 'basefrequency': 3071 return 'baseFrequency'; 3072 3073 case 'baseprofile': 3074 return 'baseProfile'; 3075 3076 case 'calcmode': 3077 return 'calcMode'; 3078 3079 case 'clippathunits': 3080 return 'clipPathUnits'; 3081 3082 case 'diffuseconstant': 3083 return 'diffuseConstant'; 3084 3085 case 'edgemode': 3086 return 'edgeMode'; 3087 3088 case 'filterunits': 3089 return 'filterUnits'; 3090 3091 case 'glyphref': 3092 return 'glyphRef'; 3093 3094 case 'gradienttransform': 3095 return 'gradientTransform'; 3096 3097 case 'gradientunits': 3098 return 'gradientUnits'; 3099 3100 case 'kernelmatrix': 3101 return 'kernelMatrix'; 3102 3103 case 'kernelunitlength': 3104 return 'kernelUnitLength'; 3105 3106 case 'keypoints': 3107 return 'keyPoints'; 3108 3109 case 'keysplines': 3110 return 'keySplines'; 3111 3112 case 'keytimes': 3113 return 'keyTimes'; 3114 3115 case 'lengthadjust': 3116 return 'lengthAdjust'; 3117 3118 case 'limitingconeangle': 3119 return 'limitingConeAngle'; 3120 3121 case 'markerheight': 3122 return 'markerHeight'; 3123 3124 case 'markerunits': 3125 return 'markerUnits'; 3126 3127 case 'markerwidth': 3128 return 'markerWidth'; 3129 3130 case 'maskcontentunits': 3131 return 'maskContentUnits'; 3132 3133 case 'maskunits': 3134 return 'maskUnits'; 3135 3136 case 'numoctaves': 3137 return 'numOctaves'; 3138 3139 case 'pathlength': 3140 return 'pathLength'; 3141 3142 case 'patterncontentunits': 3143 return 'patternContentUnits'; 3144 3145 case 'patterntransform': 3146 return 'patternTransform'; 3147 3148 case 'patternunits': 3149 return 'patternUnits'; 3150 3151 case 'pointsatx': 3152 return 'pointsAtX'; 3153 3154 case 'pointsaty': 3155 return 'pointsAtY'; 3156 3157 case 'pointsatz': 3158 return 'pointsAtZ'; 3159 3160 case 'preservealpha': 3161 return 'preserveAlpha'; 3162 3163 case 'preserveaspectratio': 3164 return 'preserveAspectRatio'; 3165 3166 case 'primitiveunits': 3167 return 'primitiveUnits'; 3168 3169 case 'refx': 3170 return 'refX'; 3171 3172 case 'refy': 3173 return 'refY'; 3174 3175 case 'repeatcount': 3176 return 'repeatCount'; 3177 3178 case 'repeatdur': 3179 return 'repeatDur'; 3180 3181 case 'requiredextensions': 3182 return 'requiredExtensions'; 3183 3184 case 'requiredfeatures': 3185 return 'requiredFeatures'; 3186 3187 case 'specularconstant': 3188 return 'specularConstant'; 3189 3190 case 'specularexponent': 3191 return 'specularExponent'; 3192 3193 case 'spreadmethod': 3194 return 'spreadMethod'; 3195 3196 case 'startoffset': 3197 return 'startOffset'; 3198 3199 case 'stddeviation': 3200 return 'stdDeviation'; 3201 3202 case 'stitchtiles': 3203 return 'stitchTiles'; 3204 3205 case 'surfacescale': 3206 return 'surfaceScale'; 3207 3208 case 'systemlanguage': 3209 return 'systemLanguage'; 3210 3211 case 'tablevalues': 3212 return 'tableValues'; 3213 3214 case 'targetx': 3215 return 'targetX'; 3216 3217 case 'targety': 3218 return 'targetY'; 3219 3220 case 'textlength': 3221 return 'textLength'; 3222 3223 case 'viewbox': 3224 return 'viewBox'; 3225 3226 case 'viewtarget': 3227 return 'viewTarget'; 3228 3229 case 'xchannelselector': 3230 return 'xChannelSelector'; 3231 3232 case 'ychannelselector': 3233 return 'yChannelSelector'; 3234 3235 case 'zoomandpan': 3236 return 'zoomAndPan'; 3237 } 3238 } 3239 3240 if ( 'html' !== $namespace ) { 3241 switch ( $lower_name ) { 3242 case 'xlink:actuate': 3243 return 'xlink actuate'; 3244 3245 case 'xlink:arcrole': 3246 return 'xlink arcrole'; 3247 3248 case 'xlink:href': 3249 return 'xlink href'; 3250 3251 case 'xlink:role': 3252 return 'xlink role'; 3253 3254 case 'xlink:show': 3255 return 'xlink show'; 3256 3257 case 'xlink:title': 3258 return 'xlink title'; 3259 3260 case 'xlink:type': 3261 return 'xlink type'; 3262 3263 case 'xml:lang': 3264 return 'xml lang'; 3265 3266 case 'xml:space': 3267 return 'xml space'; 3268 3269 case 'xmlns': 3270 return 'xmlns'; 3271 3272 case 'xmlns:xlink': 3273 return 'xmlns xlink'; 3274 } 3275 } 3276 3277 return $attribute_name; 3278 } 3279 3280 /** 3281 * Indicates if the currently matched tag contains the self-closing flag. 3282 * 3283 * No HTML elements ought to have the self-closing flag and for those, the self-closing 3284 * flag will be ignored. For void elements this is benign because they "self close" 3285 * automatically. For non-void HTML elements though problems will appear if someone 3286 * intends to use a self-closing element in place of that element with an empty body. 3287 * For HTML foreign elements and custom elements the self-closing flag determines if 3288 * they self-close or not. 3289 * 3290 * This function does not determine if a tag is self-closing, 3291 * but only if the self-closing flag is present in the syntax. 3292 * 3293 * @since 6.3.0 3294 * 3295 * @return bool Whether the currently matched tag contains the self-closing flag. 3296 */ 3297 public function has_self_closing_flag(): bool { 3298 if ( self::STATE_MATCHED_TAG !== $this->parser_state ) { 3299 return false; 3300 } 3301 3302 /* 3303 * The self-closing flag is the solidus at the _end_ of the tag, not the beginning. 3304 * 3305 * Example: 3306 * 3307 * <figure /> 3308 * ^ this appears one character before the end of the closing ">". 3309 */ 3310 return '/' === $this->html[ $this->token_starts_at + $this->token_length - 2 ]; 3311 } 3312 3313 /** 3314 * Indicates if the current tag token is a tag closer. 3315 * 3316 * Example: 3317 * 3318 * $p = new WP_HTML_Tag_Processor( '<div></div>' ); 3319 * $p->next_tag( array( 'tag_name' => 'div', 'tag_closers' => 'visit' ) ); 3320 * $p->is_tag_closer() === false; 3321 * 3322 * $p->next_tag( array( 'tag_name' => 'div', 'tag_closers' => 'visit' ) ); 3323 * $p->is_tag_closer() === true; 3324 * 3325 * @since 6.2.0 3326 * @since 6.7.0 Reports all BR tags as opening tags. 3327 * 3328 * @return bool Whether the current tag is a tag closer. 3329 */ 3330 public function is_tag_closer(): bool { 3331 return ( 3332 self::STATE_MATCHED_TAG === $this->parser_state && 3333 $this->is_closing_tag && 3334 3335 /* 3336 * The BR tag can only exist as an opening tag. If something like `</br>` 3337 * appears then the HTML parser will treat it as an opening tag with no 3338 * attributes. The BR tag is unique in this way. 3339 * 3340 * @see https://html.spec.whatwg.org/#parsing-main-inbody 3341 */ 3342 'BR' !== $this->get_tag() 3343 ); 3344 } 3345 3346 /** 3347 * Indicates the kind of matched token, if any. 3348 * 3349 * This differs from `get_token_name()` in that it always 3350 * returns a static string indicating the type, whereas 3351 * `get_token_name()` may return values derived from the 3352 * token itself, such as a tag name or processing 3353 * instruction tag. 3354 * 3355 * Possible values: 3356 * - `#tag` when matched on a tag. 3357 * - `#text` when matched on a text node. 3358 * - `#cdata-section` when matched on a CDATA node. 3359 * - `#comment` when matched on a comment. 3360 * - `#doctype` when matched on a DOCTYPE declaration. 3361 * - `#presumptuous-tag` when matched on an empty tag closer. 3362 * - `#funky-comment` when matched on a funky comment. 3363 * 3364 * @since 6.5.0 3365 * 3366 * @return string|null What kind of token is matched, or null. 3367 */ 3368 public function get_token_type(): ?string { 3369 switch ( $this->parser_state ) { 3370 case self::STATE_MATCHED_TAG: 3371 return '#tag'; 3372 3373 case self::STATE_DOCTYPE: 3374 return '#doctype'; 3375 3376 default: 3377 return $this->get_token_name(); 3378 } 3379 } 3380 3381 /** 3382 * Returns the node name represented by the token. 3383 * 3384 * This matches the DOM API value `nodeName`. Some values 3385 * are static, such as `#text` for a text node, while others 3386 * are dynamically generated from the token itself. 3387 * 3388 * Dynamic names: 3389 * - Uppercase tag name for tag matches. 3390 * - `html` for DOCTYPE declarations. 3391 * 3392 * Note that if the Tag Processor is not matched on a token 3393 * then this function will return `null`, either because it 3394 * hasn't yet found a token or because it reached the end 3395 * of the document without matching a token. 3396 * 3397 * @since 6.5.0 3398 * 3399 * @return string|null Name of the matched token. 3400 */ 3401 public function get_token_name(): ?string { 3402 switch ( $this->parser_state ) { 3403 case self::STATE_MATCHED_TAG: 3404 return $this->get_tag(); 3405 3406 case self::STATE_TEXT_NODE: 3407 return '#text'; 3408 3409 case self::STATE_CDATA_NODE: 3410 return '#cdata-section'; 3411 3412 case self::STATE_COMMENT: 3413 return '#comment'; 3414 3415 case self::STATE_DOCTYPE: 3416 return 'html'; 3417 3418 case self::STATE_PRESUMPTUOUS_TAG: 3419 return '#presumptuous-tag'; 3420 3421 case self::STATE_FUNKY_COMMENT: 3422 return '#funky-comment'; 3423 } 3424 3425 return null; 3426 } 3427 3428 /** 3429 * Indicates what kind of comment produced the comment node. 3430 * 3431 * Because there are different kinds of HTML syntax which produce 3432 * comments, the Tag Processor tracks and exposes this as a type 3433 * for the comment. Nominally only regular HTML comments exist as 3434 * they are commonly known, but a number of unrelated syntax errors 3435 * also produce comments. 3436 * 3437 * @see self::COMMENT_AS_ABRUPTLY_CLOSED_COMMENT 3438 * @see self::COMMENT_AS_CDATA_LOOKALIKE 3439 * @see self::COMMENT_AS_INVALID_HTML 3440 * @see self::COMMENT_AS_HTML_COMMENT 3441 * @see self::COMMENT_AS_PI_NODE_LOOKALIKE 3442 * 3443 * @since 6.5.0 3444 * 3445 * @return string|null 3446 */ 3447 public function get_comment_type(): ?string { 3448 if ( self::STATE_COMMENT !== $this->parser_state ) { 3449 return null; 3450 } 3451 3452 return $this->comment_type; 3453 } 3454 3455 /** 3456 * Returns the text of a matched comment or null if not on a comment type node. 3457 * 3458 * This method returns the entire text content of a comment node as it 3459 * would appear in the browser. 3460 * 3461 * This differs from {@see ::get_modifiable_text()} in that certain comment 3462 * types in the HTML API cannot allow their entire comment text content to 3463 * be modified. Namely, "bogus comments" of the form `<?not allowed in html>` 3464 * will create a comment whose text content starts with `?`. Note that if 3465 * that character were modified, it would be possible to change the node 3466 * type. 3467 * 3468 * @since 6.7.0 3469 * 3470 * @return string|null The comment text as it would appear in the browser or null 3471 * if not on a comment type node. 3472 */ 3473 public function get_full_comment_text(): ?string { 3474 if ( self::STATE_FUNKY_COMMENT === $this->parser_state ) { 3475 return $this->get_modifiable_text(); 3476 } 3477 3478 if ( self::STATE_COMMENT !== $this->parser_state ) { 3479 return null; 3480 } 3481 3482 switch ( $this->get_comment_type() ) { 3483 case self::COMMENT_AS_HTML_COMMENT: 3484 case self::COMMENT_AS_ABRUPTLY_CLOSED_COMMENT: 3485 return $this->get_modifiable_text(); 3486 3487 case self::COMMENT_AS_CDATA_LOOKALIKE: 3488 return "[CDATA[{$this->get_modifiable_text()}]]"; 3489 3490 case self::COMMENT_AS_PI_NODE_LOOKALIKE: 3491 return "?{$this->get_tag()}{$this->get_modifiable_text()}?"; 3492 3493 /* 3494 * This represents "bogus comments state" from HTML tokenization. 3495 * This can be entered by `<?` or `<!`, where `?` is included in 3496 * the comment text but `!` is not. 3497 */ 3498 case self::COMMENT_AS_INVALID_HTML: 3499 $preceding_character = $this->html[ $this->text_starts_at - 1 ]; 3500 $comment_start = '?' === $preceding_character ? '?' : ''; 3501 return "{$comment_start}{$this->get_modifiable_text()}"; 3502 } 3503 3504 return null; 3505 } 3506 3507 /** 3508 * Subdivides a matched text node, splitting NULL byte sequences and decoded whitespace as 3509 * distinct nodes prefixes. 3510 * 3511 * Note that once anything that's neither a NULL byte nor decoded whitespace is 3512 * encountered, then the remainder of the text node is left intact as generic text. 3513 * 3514 * - The HTML Processor uses this to apply distinct rules for different kinds of text. 3515 * - Inter-element whitespace can be detected and skipped with this method. 3516 * 3517 * Text nodes aren't eagerly subdivided because there's no need to split them unless 3518 * decisions are being made on NULL byte sequences or whitespace-only text. 3519 * 3520 * Example: 3521 * 3522 * $processor = new WP_HTML_Tag_Processor( "\x00Apples & Oranges" ); 3523 * true === $processor->next_token(); // Text is "Apples & Oranges". 3524 * true === $processor->subdivide_text_appropriately(); // Text is "". 3525 * true === $processor->next_token(); // Text is "Apples & Oranges". 3526 * false === $processor->subdivide_text_appropriately(); 3527 * 3528 * $processor = new WP_HTML_Tag_Processor( " \r\n\tMore" ); 3529 * true === $processor->next_token(); // Text is " ␉More". 3530 * true === $processor->subdivide_text_appropriately(); // Text is " ␉". 3531 * true === $processor->next_token(); // Text is "More". 3532 * false === $processor->subdivide_text_appropriately(); 3533 * 3534 * @since 6.7.0 3535 * 3536 * @return bool Whether the text node was subdivided. 3537 */ 3538 public function subdivide_text_appropriately(): bool { 3539 if ( self::STATE_TEXT_NODE !== $this->parser_state ) { 3540 return false; 3541 } 3542 3543 $this->text_node_classification = self::TEXT_IS_GENERIC; 3544 3545 /* 3546 * NULL bytes are treated categorically different than numeric character 3547 * references whose number is zero. `�` is not the same as `"\x00"`. 3548 */ 3549 $leading_nulls = strspn( $this->html, "\x00", $this->text_starts_at, $this->text_length ); 3550 if ( $leading_nulls > 0 ) { 3551 $this->token_length = $leading_nulls; 3552 $this->text_length = $leading_nulls; 3553 $this->bytes_already_parsed = $this->token_starts_at + $leading_nulls; 3554 $this->text_node_classification = self::TEXT_IS_NULL_SEQUENCE; 3555 return true; 3556 } 3557 3558 /* 3559 * Start a decoding loop to determine the point at which the 3560 * text subdivides. This entails raw whitespace bytes and any 3561 * character reference that decodes to the same. 3562 */ 3563 $at = $this->text_starts_at; 3564 $end = $this->text_starts_at + $this->text_length; 3565 while ( $at < $end ) { 3566 $skipped = strspn( $this->html, " \t\f\r\n", $at, $end - $at ); 3567 $at += $skipped; 3568 3569 if ( $at < $end && '&' === $this->html[ $at ] ) { 3570 $matched_byte_length = null; 3571 $replacement = WP_HTML_Decoder::read_character_reference( 'data', $this->html, $at, $matched_byte_length ); 3572 if ( isset( $replacement ) && 1 === strspn( $replacement, " \t\f\r\n" ) ) { 3573 $at += $matched_byte_length; 3574 continue; 3575 } 3576 } 3577 3578 break; 3579 } 3580 3581 if ( $at > $this->text_starts_at ) { 3582 $new_length = $at - $this->text_starts_at; 3583 $this->text_length = $new_length; 3584 $this->token_length = $new_length; 3585 $this->bytes_already_parsed = $at; 3586 $this->text_node_classification = self::TEXT_IS_WHITESPACE; 3587 return true; 3588 } 3589 3590 return false; 3591 } 3592 3593 /** 3594 * Returns the modifiable text for a matched token, or an empty string. 3595 * 3596 * Modifiable text is text content that may be read and changed without 3597 * changing the HTML structure of the document around it. This includes 3598 * the contents of `#text` nodes in the HTML as well as the inner 3599 * contents of HTML comments, Processing Instructions, and others, even 3600 * though these nodes aren't part of a parsed DOM tree. They also contain 3601 * the contents of SCRIPT and STYLE tags, of TEXTAREA tags, and of any 3602 * other section in an HTML document which cannot contain HTML markup (DATA). 3603 * 3604 * If a token has no modifiable text then an empty string is returned to 3605 * avoid needless crashing or type errors. An empty string does not mean 3606 * that a token has modifiable text, and a token with modifiable text may 3607 * have an empty string (e.g. a comment with no contents). 3608 * 3609 * Limitations: 3610 * 3611 * - This function will not strip the leading newline appropriately 3612 * after seeking into a LISTING or PRE element. To ensure that the 3613 * newline is treated properly, seek to the LISTING or PRE opening 3614 * tag instead of to the first text node inside the element. 3615 * 3616 * @since 6.5.0 3617 * @since 6.7.0 Replaces NULL bytes (U+0000) and newlines appropriately. 3618 * 3619 * @return string 3620 */ 3621 public function get_modifiable_text(): string { 3622 $has_enqueued_update = isset( $this->lexical_updates['modifiable text'] ); 3623 3624 if ( ! $has_enqueued_update && ( null === $this->text_starts_at || 0 === $this->text_length ) ) { 3625 return ''; 3626 } 3627 3628 $text = $has_enqueued_update 3629 ? $this->lexical_updates['modifiable text']->text 3630 : substr( $this->html, $this->text_starts_at, $this->text_length ); 3631 3632 /* 3633 * Pre-processing the input stream would normally happen before 3634 * any parsing is done, but deferring it means it's possible to 3635 * skip in most cases. When getting the modifiable text, however 3636 * it's important to apply the pre-processing steps, which is 3637 * normalizing newlines. 3638 * 3639 * @see https://html.spec.whatwg.org/#preprocessing-the-input-stream 3640 * @see https://infra.spec.whatwg.org/#normalize-newlines 3641 */ 3642 $text = str_replace( "\r\n", "\n", $text ); 3643 $text = str_replace( "\r", "\n", $text ); 3644 3645 // Comment data is not decoded. 3646 if ( 3647 self::STATE_CDATA_NODE === $this->parser_state || 3648 self::STATE_COMMENT === $this->parser_state || 3649 self::STATE_DOCTYPE === $this->parser_state || 3650 self::STATE_FUNKY_COMMENT === $this->parser_state 3651 ) { 3652 return str_replace( "\x00", "\u{FFFD}", $text ); 3653 } 3654 3655 $tag_name = $this->get_token_name(); 3656 if ( 3657 // Script data is not decoded. 3658 'SCRIPT' === $tag_name || 3659 3660 // RAWTEXT data is not decoded. 3661 'IFRAME' === $tag_name || 3662 'NOEMBED' === $tag_name || 3663 'NOFRAMES' === $tag_name || 3664 'STYLE' === $tag_name || 3665 'XMP' === $tag_name 3666 ) { 3667 return str_replace( "\x00", "\u{FFFD}", $text ); 3668 } 3669 3670 $decoded = WP_HTML_Decoder::decode_text_node( $text ); 3671 3672 /* 3673 * Skip the first line feed after LISTING, PRE, and TEXTAREA opening tags. 3674 * 3675 * Note that this first newline may come in the form of a character 3676 * reference, such as `
`, and so it's important to perform 3677 * this transformation only after decoding the raw text content. 3678 */ 3679 if ( 3680 ( "\n" === ( $decoded[0] ?? '' ) ) && 3681 ( ( $this->skip_newline_at === $this->token_starts_at && '#text' === $tag_name ) || 'TEXTAREA' === $tag_name ) 3682 ) { 3683 $decoded = substr( $decoded, 1 ); 3684 } 3685 3686 /* 3687 * Only in normative text nodes does the NULL byte (U+0000) get removed. 3688 * In all other contexts it's replaced by the replacement character (U+FFFD) 3689 * for security reasons (to avoid joining together strings that were safe 3690 * when separated, but not when joined). 3691 * 3692 * @todo Inside HTML integration points and MathML integration points, the 3693 * text is processed according to the insertion mode, not according 3694 * to the foreign content rules. This should strip the NULL bytes. 3695 */ 3696 return ( '#text' === $tag_name && 'html' === $this->get_namespace() ) 3697 ? str_replace( "\x00", '', $decoded ) 3698 : str_replace( "\x00", "\u{FFFD}", $decoded ); 3699 } 3700 3701 /** 3702 * Sets the modifiable text for the matched token, if matched. 3703 * 3704 * Modifiable text is text content that may be read and changed without 3705 * changing the HTML structure of the document around it. This includes 3706 * the contents of `#text` nodes in the HTML as well as the inner 3707 * contents of HTML comments, Processing Instructions, and others, even 3708 * though these nodes aren't part of a parsed DOM tree. They also contain 3709 * the contents of SCRIPT and STYLE tags, of TEXTAREA tags, and of any 3710 * other section in an HTML document which cannot contain HTML markup (DATA). 3711 * 3712 * Not all modifiable text may be set by this method, and not all content 3713 * may be set as modifiable text. In the case that this fails it will return 3714 * `false` indicating as much. For instance, it will not allow inserting the 3715 * string `</script` into a SCRIPT element, because the rules for escaping 3716 * that safely are complicated. Similarly, it will not allow setting content 3717 * into a comment which would prematurely terminate the comment. 3718 * 3719 * Example: 3720 * 3721 * // Add a preface to all STYLE contents. 3722 * while ( $processor->next_tag( 'STYLE' ) ) { 3723 * $style = $processor->get_modifiable_text(); 3724 * $processor->set_modifiable_text( "// Made with love on the World Wide Web\n{$style}" ); 3725 * } 3726 * 3727 * // Replace smiley text with Emoji smilies. 3728 * while ( $processor->next_token() ) { 3729 * if ( '#text' !== $processor->get_token_name() ) { 3730 * continue; 3731 * } 3732 * 3733 * $chunk = $processor->get_modifiable_text(); 3734 * if ( ! str_contains( $chunk, ':)' ) ) { 3735 * continue; 3736 * } 3737 * 3738 * $processor->set_modifiable_text( str_replace( ':)', '🙂', $chunk ) ); 3739 * } 3740 * 3741 * @since 6.7.0 3742 * 3743 * @param string $plaintext_content New text content to represent in the matched token. 3744 * 3745 * @return bool Whether the text was able to update. 3746 */ 3747 public function set_modifiable_text( string $plaintext_content ): bool { 3748 if ( self::STATE_TEXT_NODE === $this->parser_state ) { 3749 $this->lexical_updates['modifiable text'] = new WP_HTML_Text_Replacement( 3750 $this->text_starts_at, 3751 $this->text_length, 3752 htmlspecialchars( $plaintext_content, ENT_QUOTES | ENT_HTML5 ) 3753 ); 3754 3755 return true; 3756 } 3757 3758 // Comment data is not encoded. 3759 if ( 3760 self::STATE_COMMENT === $this->parser_state && 3761 self::COMMENT_AS_HTML_COMMENT === $this->comment_type 3762 ) { 3763 // Check if the text could close the comment. 3764 if ( 1 === preg_match( '/--!?>/', $plaintext_content ) ) { 3765 return false; 3766 } 3767 3768 $this->lexical_updates['modifiable text'] = new WP_HTML_Text_Replacement( 3769 $this->text_starts_at, 3770 $this->text_length, 3771 $plaintext_content 3772 ); 3773 3774 return true; 3775 } 3776 3777 if ( self::STATE_MATCHED_TAG !== $this->parser_state ) { 3778 return false; 3779 } 3780 3781 switch ( $this->get_tag() ) { 3782 case 'SCRIPT': 3783 /** 3784 * This is over-protective, but ensures the update doesn't break 3785 * the HTML structure of the SCRIPT element. 3786 * 3787 * More thorough analysis could track the HTML tokenizer states 3788 * and to ensure that the SCRIPT element closes at the expected 3789 * SCRIPT close tag as is done in {@see ::skip_script_data()}. 3790 * 3791 * A SCRIPT element could be closed prematurely by contents 3792 * like `</script>`. A SCRIPT element could be prevented from 3793 * closing by contents like `<!--<script>`. 3794 * 3795 * The following strings are essential for dangerous content, 3796 * although they are insufficient on their own. This trade-off 3797 * prevents dangerous scripts from being sent to the browser. 3798 * It is also unlikely to produce HTML that may confuse more 3799 * basic HTML tooling. 3800 */ 3801 if ( 3802 false !== stripos( $plaintext_content, '</script' ) || 3803 false !== stripos( $plaintext_content, '<script' ) 3804 ) { 3805 return false; 3806 } 3807 3808 $this->lexical_updates['modifiable text'] = new WP_HTML_Text_Replacement( 3809 $this->text_starts_at, 3810 $this->text_length, 3811 $plaintext_content 3812 ); 3813 3814 return true; 3815 3816 case 'STYLE': 3817 $plaintext_content = preg_replace_callback( 3818 '~</(?P<TAG_NAME>style)~i', 3819 static function ( $tag_match ) { 3820 return "\\3c\\2f{$tag_match['TAG_NAME']}"; 3821 }, 3822 $plaintext_content 3823 ); 3824 3825 $this->lexical_updates['modifiable text'] = new WP_HTML_Text_Replacement( 3826 $this->text_starts_at, 3827 $this->text_length, 3828 $plaintext_content 3829 ); 3830 3831 return true; 3832 3833 case 'TEXTAREA': 3834 case 'TITLE': 3835 $plaintext_content = preg_replace_callback( 3836 "~</(?P<TAG_NAME>{$this->get_tag()})~i", 3837 static function ( $tag_match ) { 3838 return "</{$tag_match['TAG_NAME']}"; 3839 }, 3840 $plaintext_content 3841 ); 3842 3843 /* 3844 * These don't _need_ to be escaped, but since they are decoded it's 3845 * safe to leave them escaped and this can prevent other code from 3846 * naively detecting tags within the contents. 3847 * 3848 * @todo It would be useful to prefix a multiline replacement text 3849 * with a newline, but not necessary. This is for aesthetics. 3850 */ 3851 $this->lexical_updates['modifiable text'] = new WP_HTML_Text_Replacement( 3852 $this->text_starts_at, 3853 $this->text_length, 3854 $plaintext_content 3855 ); 3856 3857 return true; 3858 } 3859 3860 return false; 3861 } 3862 3863 /** 3864 * Updates or creates a new attribute on the currently matched tag with the passed value. 3865 * 3866 * For boolean attributes special handling is provided: 3867 * - When `true` is passed as the value, then only the attribute name is added to the tag. 3868 * - When `false` is passed, the attribute gets removed if it existed before. 3869 * 3870 * For string attributes, the value is escaped using the `esc_attr` function. 3871 * 3872 * @since 6.2.0 3873 * @since 6.2.1 Fix: Only create a single update for multiple calls with case-variant attribute names. 3874 * 3875 * @param string $name The attribute name to target. 3876 * @param string|bool $value The new attribute value. 3877 * @return bool Whether an attribute value was set. 3878 */ 3879 public function set_attribute( $name, $value ): bool { 3880 if ( 3881 self::STATE_MATCHED_TAG !== $this->parser_state || 3882 $this->is_closing_tag 3883 ) { 3884 return false; 3885 } 3886 3887 /* 3888 * WordPress rejects more characters than are strictly forbidden 3889 * in HTML5. This is to prevent additional security risks deeper 3890 * in the WordPress and plugin stack. Specifically the 3891 * less-than (<) greater-than (>) and ampersand (&) aren't allowed. 3892 * 3893 * The use of a PCRE match enables looking for specific Unicode 3894 * code points without writing a UTF-8 decoder. Whereas scanning 3895 * for one-byte characters is trivial (with `strcspn`), scanning 3896 * for the longer byte sequences would be more complicated. Given 3897 * that this shouldn't be in the hot path for execution, it's a 3898 * reasonable compromise in efficiency without introducing a 3899 * noticeable impact on the overall system. 3900 * 3901 * @see https://html.spec.whatwg.org/#attributes-2 3902 * 3903 * @todo As the only regex pattern maybe we should take it out? 3904 * Are Unicode patterns available broadly in Core? 3905 */ 3906 if ( preg_match( 3907 '~[' . 3908 // Syntax-like characters. 3909 '"\'>&</ =' . 3910 // Control characters. 3911 '\x{00}-\x{1F}' . 3912 // HTML noncharacters. 3913 '\x{FDD0}-\x{FDEF}' . 3914 '\x{FFFE}\x{FFFF}\x{1FFFE}\x{1FFFF}\x{2FFFE}\x{2FFFF}\x{3FFFE}\x{3FFFF}' . 3915 '\x{4FFFE}\x{4FFFF}\x{5FFFE}\x{5FFFF}\x{6FFFE}\x{6FFFF}\x{7FFFE}\x{7FFFF}' . 3916 '\x{8FFFE}\x{8FFFF}\x{9FFFE}\x{9FFFF}\x{AFFFE}\x{AFFFF}\x{BFFFE}\x{BFFFF}' . 3917 '\x{CFFFE}\x{CFFFF}\x{DFFFE}\x{DFFFF}\x{EFFFE}\x{EFFFF}\x{FFFFE}\x{FFFFF}' . 3918 '\x{10FFFE}\x{10FFFF}' . 3919 ']~Ssu', 3920 $name 3921 ) ) { 3922 _doing_it_wrong( 3923 __METHOD__, 3924 __( 'Invalid attribute name.' ), 3925 '6.2.0' 3926 ); 3927 3928 return false; 3929 } 3930 3931 /* 3932 * > The values "true" and "false" are not allowed on boolean attributes. 3933 * > To represent a false value, the attribute has to be omitted altogether. 3934 * - HTML5 spec, https://html.spec.whatwg.org/#boolean-attributes 3935 */ 3936 if ( false === $value ) { 3937 return $this->remove_attribute( $name ); 3938 } 3939 3940 if ( true === $value ) { 3941 $updated_attribute = $name; 3942 } else { 3943 $comparable_name = strtolower( $name ); 3944 3945 /* 3946 * Escape URL attributes. 3947 * 3948 * @see https://html.spec.whatwg.org/#attributes-3 3949 */ 3950 $escaped_new_value = in_array( $comparable_name, wp_kses_uri_attributes(), true ) ? esc_url( $value ) : esc_attr( $value ); 3951 3952 // If the escaping functions wiped out the update, reject it and indicate it was rejected. 3953 if ( '' === $escaped_new_value && '' !== $value ) { 3954 return false; 3955 } 3956 3957 $updated_attribute = "{$name}=\"{$escaped_new_value}\""; 3958 } 3959 3960 /* 3961 * > There must never be two or more attributes on 3962 * > the same start tag whose names are an ASCII 3963 * > case-insensitive match for each other. 3964 * - HTML 5 spec 3965 * 3966 * @see https://html.spec.whatwg.org/multipage/syntax.html#attributes-2:ascii-case-insensitive 3967 */ 3968 $comparable_name = strtolower( $name ); 3969 3970 if ( isset( $this->attributes[ $comparable_name ] ) ) { 3971 /* 3972 * Update an existing attribute. 3973 * 3974 * Example – set attribute id to "new" in <div id="initial_id" />: 3975 * 3976 * <div id="initial_id"/> 3977 * ^-------------^ 3978 * start end 3979 * replacement: `id="new"` 3980 * 3981 * Result: <div id="new"/> 3982 */ 3983 $existing_attribute = $this->attributes[ $comparable_name ]; 3984 $this->lexical_updates[ $comparable_name ] = new WP_HTML_Text_Replacement( 3985 $existing_attribute->start, 3986 $existing_attribute->length, 3987 $updated_attribute 3988 ); 3989 } else { 3990 /* 3991 * Create a new attribute at the tag's name end. 3992 * 3993 * Example – add attribute id="new" to <div />: 3994 * 3995 * <div/> 3996 * ^ 3997 * start and end 3998 * replacement: ` id="new"` 3999 * 4000 * Result: <div id="new"/> 4001 */ 4002 $this->lexical_updates[ $comparable_name ] = new WP_HTML_Text_Replacement( 4003 $this->tag_name_starts_at + $this->tag_name_length, 4004 0, 4005 ' ' . $updated_attribute 4006 ); 4007 } 4008 4009 /* 4010 * Any calls to update the `class` attribute directly should wipe out any 4011 * enqueued class changes from `add_class` and `remove_class`. 4012 */ 4013 if ( 'class' === $comparable_name && ! empty( $this->classname_updates ) ) { 4014 $this->classname_updates = array(); 4015 } 4016 4017 return true; 4018 } 4019 4020 /** 4021 * Remove an attribute from the currently-matched tag. 4022 * 4023 * @since 6.2.0 4024 * 4025 * @param string $name The attribute name to remove. 4026 * @return bool Whether an attribute was removed. 4027 */ 4028 public function remove_attribute( $name ): bool { 4029 if ( 4030 self::STATE_MATCHED_TAG !== $this->parser_state || 4031 $this->is_closing_tag 4032 ) { 4033 return false; 4034 } 4035 4036 /* 4037 * > There must never be two or more attributes on 4038 * > the same start tag whose names are an ASCII 4039 * > case-insensitive match for each other. 4040 * - HTML 5 spec 4041 * 4042 * @see https://html.spec.whatwg.org/multipage/syntax.html#attributes-2:ascii-case-insensitive 4043 */ 4044 $name = strtolower( $name ); 4045 4046 /* 4047 * Any calls to update the `class` attribute directly should wipe out any 4048 * enqueued class changes from `add_class` and `remove_class`. 4049 */ 4050 if ( 'class' === $name && count( $this->classname_updates ) !== 0 ) { 4051 $this->classname_updates = array(); 4052 } 4053 4054 /* 4055 * If updating an attribute that didn't exist in the input 4056 * document, then remove the enqueued update and move on. 4057 * 4058 * For example, this might occur when calling `remove_attribute()` 4059 * after calling `set_attribute()` for the same attribute 4060 * and when that attribute wasn't originally present. 4061 */ 4062 if ( ! isset( $this->attributes[ $name ] ) ) { 4063 if ( isset( $this->lexical_updates[ $name ] ) ) { 4064 unset( $this->lexical_updates[ $name ] ); 4065 } 4066 return false; 4067 } 4068 4069 /* 4070 * Removes an existing tag attribute. 4071 * 4072 * Example – remove the attribute id from <div id="main"/>: 4073 * <div id="initial_id"/> 4074 * ^-------------^ 4075 * start end 4076 * replacement: `` 4077 * 4078 * Result: <div /> 4079 */ 4080 $this->lexical_updates[ $name ] = new WP_HTML_Text_Replacement( 4081 $this->attributes[ $name ]->start, 4082 $this->attributes[ $name ]->length, 4083 '' 4084 ); 4085 4086 // Removes any duplicated attributes if they were also present. 4087 foreach ( $this->duplicate_attributes[ $name ] ?? array() as $attribute_token ) { 4088 $this->lexical_updates[] = new WP_HTML_Text_Replacement( 4089 $attribute_token->start, 4090 $attribute_token->length, 4091 '' 4092 ); 4093 } 4094 4095 return true; 4096 } 4097 4098 /** 4099 * Adds a new class name to the currently matched tag. 4100 * 4101 * @since 6.2.0 4102 * 4103 * @param string $class_name The class name to add. 4104 * @return bool Whether the class was set to be added. 4105 */ 4106 public function add_class( $class_name ): bool { 4107 if ( 4108 self::STATE_MATCHED_TAG !== $this->parser_state || 4109 $this->is_closing_tag 4110 ) { 4111 return false; 4112 } 4113 4114 if ( self::QUIRKS_MODE !== $this->compat_mode ) { 4115 $this->classname_updates[ $class_name ] = self::ADD_CLASS; 4116 return true; 4117 } 4118 4119 /* 4120 * Because class names are matched ASCII-case-insensitively in quirks mode, 4121 * this needs to see if a case variant of the given class name is already 4122 * enqueued and update that existing entry, if so. This picks the casing of 4123 * the first-provided class name for all lexical variations. 4124 */ 4125 $class_name_length = strlen( $class_name ); 4126 foreach ( $this->classname_updates as $updated_name => $action ) { 4127 if ( 4128 strlen( $updated_name ) === $class_name_length && 4129 0 === substr_compare( $updated_name, $class_name, 0, $class_name_length, true ) 4130 ) { 4131 $this->classname_updates[ $updated_name ] = self::ADD_CLASS; 4132 return true; 4133 } 4134 } 4135 4136 $this->classname_updates[ $class_name ] = self::ADD_CLASS; 4137 return true; 4138 } 4139 4140 /** 4141 * Removes a class name from the currently matched tag. 4142 * 4143 * @since 6.2.0 4144 * 4145 * @param string $class_name The class name to remove. 4146 * @return bool Whether the class was set to be removed. 4147 */ 4148 public function remove_class( $class_name ): bool { 4149 if ( 4150 self::STATE_MATCHED_TAG !== $this->parser_state || 4151 $this->is_closing_tag 4152 ) { 4153 return false; 4154 } 4155 4156 if ( self::QUIRKS_MODE !== $this->compat_mode ) { 4157 $this->classname_updates[ $class_name ] = self::REMOVE_CLASS; 4158 return true; 4159 } 4160 4161 /* 4162 * Because class names are matched ASCII-case-insensitively in quirks mode, 4163 * this needs to see if a case variant of the given class name is already 4164 * enqueued and update that existing entry, if so. This picks the casing of 4165 * the first-provided class name for all lexical variations. 4166 */ 4167 $class_name_length = strlen( $class_name ); 4168 foreach ( $this->classname_updates as $updated_name => $action ) { 4169 if ( 4170 strlen( $updated_name ) === $class_name_length && 4171 0 === substr_compare( $updated_name, $class_name, 0, $class_name_length, true ) 4172 ) { 4173 $this->classname_updates[ $updated_name ] = self::REMOVE_CLASS; 4174 return true; 4175 } 4176 } 4177 4178 $this->classname_updates[ $class_name ] = self::REMOVE_CLASS; 4179 return true; 4180 } 4181 4182 /** 4183 * Returns the string representation of the HTML Tag Processor. 4184 * 4185 * @since 6.2.0 4186 * 4187 * @see WP_HTML_Tag_Processor::get_updated_html() 4188 * 4189 * @return string The processed HTML. 4190 */ 4191 public function __toString(): string { 4192 return $this->get_updated_html(); 4193 } 4194 4195 /** 4196 * Returns the string representation of the HTML Tag Processor. 4197 * 4198 * @since 6.2.0 4199 * @since 6.2.1 Shifts the internal cursor corresponding to the applied updates. 4200 * @since 6.4.0 No longer calls subclass method `next_tag()` after updating HTML. 4201 * 4202 * @return string The processed HTML. 4203 */ 4204 public function get_updated_html(): string { 4205 $requires_no_updating = 0 === count( $this->classname_updates ) && 0 === count( $this->lexical_updates ); 4206 4207 /* 4208 * When there is nothing more to update and nothing has already been 4209 * updated, return the original document and avoid a string copy. 4210 */ 4211 if ( $requires_no_updating ) { 4212 return $this->html; 4213 } 4214 4215 /* 4216 * Keep track of the position right before the current tag. This will 4217 * be necessary for reparsing the current tag after updating the HTML. 4218 */ 4219 $before_current_tag = $this->token_starts_at ?? 0; 4220 4221 /* 4222 * 1. Apply the enqueued edits and update all the pointers to reflect those changes. 4223 */ 4224 $this->class_name_updates_to_attributes_updates(); 4225 $before_current_tag += $this->apply_attributes_updates( $before_current_tag ); 4226 4227 /* 4228 * 2. Rewind to before the current tag and reparse to get updated attributes. 4229 * 4230 * At this point the internal cursor points to the end of the tag name. 4231 * Rewind before the tag name starts so that it's as if the cursor didn't 4232 * move; a call to `next_tag()` will reparse the recently-updated attributes 4233 * and additional calls to modify the attributes will apply at this same 4234 * location, but in order to avoid issues with subclasses that might add 4235 * behaviors to `next_tag()`, the internal methods should be called here 4236 * instead. 4237 * 4238 * It's important to note that in this specific place there will be no change 4239 * because the processor was already at a tag when this was called and it's 4240 * rewinding only to the beginning of this very tag before reprocessing it 4241 * and its attributes. 4242 * 4243 * <p>Previous HTML<em>More HTML</em></p> 4244 * ↑ │ back up by the length of the tag name plus the opening < 4245 * └←─┘ back up by strlen("em") + 1 ==> 3 4246 */ 4247 $this->bytes_already_parsed = $before_current_tag; 4248 $this->base_class_next_token(); 4249 4250 return $this->html; 4251 } 4252 4253 /** 4254 * Parses tag query input into internal search criteria. 4255 * 4256 * @since 6.2.0 4257 * 4258 * @param array|string|null $query { 4259 * Optional. Which tag name to find, having which class, etc. Default is to find any tag. 4260 * 4261 * @type string|null $tag_name Which tag to find, or `null` for "any tag." 4262 * @type int|null $match_offset Find the Nth tag matching all search criteria. 4263 * 1 for "first" tag, 3 for "third," etc. 4264 * Defaults to first tag. 4265 * @type string|null $class_name Tag must contain this class name to match. 4266 * @type string $tag_closers "visit" or "skip": whether to stop on tag closers, e.g. </div>. 4267 * } 4268 */ 4269 private function parse_query( $query ) { 4270 if ( null !== $query && $query === $this->last_query ) { 4271 return; 4272 } 4273 4274 $this->last_query = $query; 4275 $this->sought_tag_name = null; 4276 $this->sought_class_name = null; 4277 $this->sought_match_offset = 1; 4278 $this->stop_on_tag_closers = false; 4279 4280 // A single string value means "find the tag of this name". 4281 if ( is_string( $query ) ) { 4282 $this->sought_tag_name = $query; 4283 return; 4284 } 4285 4286 // An empty query parameter applies no restrictions on the search. 4287 if ( null === $query ) { 4288 return; 4289 } 4290 4291 // If not using the string interface, an associative array is required. 4292 if ( ! is_array( $query ) ) { 4293 _doing_it_wrong( 4294 __METHOD__, 4295 __( 'The query argument must be an array or a tag name.' ), 4296 '6.2.0' 4297 ); 4298 return; 4299 } 4300 4301 if ( isset( $query['tag_name'] ) && is_string( $query['tag_name'] ) ) { 4302 $this->sought_tag_name = $query['tag_name']; 4303 } 4304 4305 if ( isset( $query['class_name'] ) && is_string( $query['class_name'] ) ) { 4306 $this->sought_class_name = $query['class_name']; 4307 } 4308 4309 if ( isset( $query['match_offset'] ) && is_int( $query['match_offset'] ) && 0 < $query['match_offset'] ) { 4310 $this->sought_match_offset = $query['match_offset']; 4311 } 4312 4313 if ( isset( $query['tag_closers'] ) ) { 4314 $this->stop_on_tag_closers = 'visit' === $query['tag_closers']; 4315 } 4316 } 4317 4318 4319 /** 4320 * Checks whether a given tag and its attributes match the search criteria. 4321 * 4322 * @since 6.2.0 4323 * 4324 * @return bool Whether the given tag and its attribute match the search criteria. 4325 */ 4326 private function matches(): bool { 4327 if ( $this->is_closing_tag && ! $this->stop_on_tag_closers ) { 4328 return false; 4329 } 4330 4331 // Does the tag name match the requested tag name in a case-insensitive manner? 4332 if ( 4333 isset( $this->sought_tag_name ) && 4334 ( 4335 strlen( $this->sought_tag_name ) !== $this->tag_name_length || 4336 0 !== substr_compare( $this->html, $this->sought_tag_name, $this->tag_name_starts_at, $this->tag_name_length, true ) 4337 ) 4338 ) { 4339 return false; 4340 } 4341 4342 if ( null !== $this->sought_class_name && ! $this->has_class( $this->sought_class_name ) ) { 4343 return false; 4344 } 4345 4346 return true; 4347 } 4348 4349 /** 4350 * Gets DOCTYPE declaration info from a DOCTYPE token. 4351 * 4352 * DOCTYPE tokens may appear in many places in an HTML document. In most places, they are 4353 * simply ignored. The main parsing functions find the basic shape of DOCTYPE tokens but 4354 * do not perform detailed parsing. 4355 * 4356 * This method can be called to perform a full parse of the DOCTYPE token and retrieve 4357 * its information. 4358 * 4359 * @return WP_HTML_Doctype_Info|null The DOCTYPE declaration information or `null` if not 4360 * currently at a DOCTYPE node. 4361 */ 4362 public function get_doctype_info(): ?WP_HTML_Doctype_Info { 4363 if ( self::STATE_DOCTYPE !== $this->parser_state ) { 4364 return null; 4365 } 4366 4367 return WP_HTML_Doctype_Info::from_doctype_token( substr( $this->html, $this->token_starts_at, $this->token_length ) ); 4368 } 4369 4370 /** 4371 * Parser Ready State. 4372 * 4373 * Indicates that the parser is ready to run and waiting for a state transition. 4374 * It may not have started yet, or it may have just finished parsing a token and 4375 * is ready to find the next one. 4376 * 4377 * @since 6.5.0 4378 * 4379 * @access private 4380 */ 4381 const STATE_READY = 'STATE_READY'; 4382 4383 /** 4384 * Parser Complete State. 4385 * 4386 * Indicates that the parser has reached the end of the document and there is 4387 * nothing left to scan. It finished parsing the last token completely. 4388 * 4389 * @since 6.5.0 4390 * 4391 * @access private 4392 */ 4393 const STATE_COMPLETE = 'STATE_COMPLETE'; 4394 4395 /** 4396 * Parser Incomplete Input State. 4397 * 4398 * Indicates that the parser has reached the end of the document before finishing 4399 * a token. It started parsing a token but there is a possibility that the input 4400 * HTML document was truncated in the middle of a token. 4401 * 4402 * The parser is reset at the start of the incomplete token and has paused. There 4403 * is nothing more than can be scanned unless provided a more complete document. 4404 * 4405 * @since 6.5.0 4406 * 4407 * @access private 4408 */ 4409 const STATE_INCOMPLETE_INPUT = 'STATE_INCOMPLETE_INPUT'; 4410 4411 /** 4412 * Parser Matched Tag State. 4413 * 4414 * Indicates that the parser has found an HTML tag and it's possible to get 4415 * the tag name and read or modify its attributes (if it's not a closing tag). 4416 * 4417 * @since 6.5.0 4418 * 4419 * @access private 4420 */ 4421 const STATE_MATCHED_TAG = 'STATE_MATCHED_TAG'; 4422 4423 /** 4424 * Parser Text Node State. 4425 * 4426 * Indicates that the parser has found a text node and it's possible 4427 * to read and modify that text. 4428 * 4429 * @since 6.5.0 4430 * 4431 * @access private 4432 */ 4433 const STATE_TEXT_NODE = 'STATE_TEXT_NODE'; 4434 4435 /** 4436 * Parser CDATA Node State. 4437 * 4438 * Indicates that the parser has found a CDATA node and it's possible 4439 * to read and modify its modifiable text. Note that in HTML there are 4440 * no CDATA nodes outside of foreign content (SVG and MathML). Outside 4441 * of foreign content, they are treated as HTML comments. 4442 * 4443 * @since 6.5.0 4444 * 4445 * @access private 4446 */ 4447 const STATE_CDATA_NODE = 'STATE_CDATA_NODE'; 4448 4449 /** 4450 * Indicates that the parser has found an HTML comment and it's 4451 * possible to read and modify its modifiable text. 4452 * 4453 * @since 6.5.0 4454 * 4455 * @access private 4456 */ 4457 const STATE_COMMENT = 'STATE_COMMENT'; 4458 4459 /** 4460 * Indicates that the parser has found a DOCTYPE node and it's 4461 * possible to read its DOCTYPE information via `get_doctype_info()`. 4462 * 4463 * @since 6.5.0 4464 * 4465 * @access private 4466 */ 4467 const STATE_DOCTYPE = 'STATE_DOCTYPE'; 4468 4469 /** 4470 * Indicates that the parser has found an empty tag closer `</>`. 4471 * 4472 * Note that in HTML there are no empty tag closers, and they 4473 * are ignored. Nonetheless, the Tag Processor still 4474 * recognizes them as they appear in the HTML stream. 4475 * 4476 * These were historically discussed as a "presumptuous tag 4477 * closer," which would close the nearest open tag, but were 4478 * dismissed in favor of explicitly-closing tags. 4479 * 4480 * @since 6.5.0 4481 * 4482 * @access private 4483 */ 4484 const STATE_PRESUMPTUOUS_TAG = 'STATE_PRESUMPTUOUS_TAG'; 4485 4486 /** 4487 * Indicates that the parser has found a "funky comment" 4488 * and it's possible to read and modify its modifiable text. 4489 * 4490 * Example: 4491 * 4492 * </%url> 4493 * </{"wp-bit":"query/post-author"}> 4494 * </2> 4495 * 4496 * Funky comments are tag closers with invalid tag names. Note 4497 * that in HTML these are turn into bogus comments. Nonetheless, 4498 * the Tag Processor recognizes them in a stream of HTML and 4499 * exposes them for inspection and modification. 4500 * 4501 * @since 6.5.0 4502 * 4503 * @access private 4504 */ 4505 const STATE_FUNKY_COMMENT = 'STATE_WP_FUNKY'; 4506 4507 /** 4508 * Indicates that a comment was created when encountering abruptly-closed HTML comment. 4509 * 4510 * Example: 4511 * 4512 * <!--> 4513 * <!---> 4514 * 4515 * @since 6.5.0 4516 */ 4517 const COMMENT_AS_ABRUPTLY_CLOSED_COMMENT = 'COMMENT_AS_ABRUPTLY_CLOSED_COMMENT'; 4518 4519 /** 4520 * Indicates that a comment would be parsed as a CDATA node, 4521 * were HTML to allow CDATA nodes outside of foreign content. 4522 * 4523 * Example: 4524 * 4525 * <![CDATA[This is a CDATA node.]]> 4526 * 4527 * This is an HTML comment, but it looks like a CDATA node. 4528 * 4529 * @since 6.5.0 4530 */ 4531 const COMMENT_AS_CDATA_LOOKALIKE = 'COMMENT_AS_CDATA_LOOKALIKE'; 4532 4533 /** 4534 * Indicates that a comment was created when encountering 4535 * normative HTML comment syntax. 4536 * 4537 * Example: 4538 * 4539 * <!-- this is a comment --> 4540 * 4541 * @since 6.5.0 4542 */ 4543 const COMMENT_AS_HTML_COMMENT = 'COMMENT_AS_HTML_COMMENT'; 4544 4545 /** 4546 * Indicates that a comment would be parsed as a Processing 4547 * Instruction node, were they to exist within HTML. 4548 * 4549 * Example: 4550 * 4551 * <?wp __( 'Like' ) ?> 4552 * 4553 * This is an HTML comment, but it looks like a CDATA node. 4554 * 4555 * @since 6.5.0 4556 */ 4557 const COMMENT_AS_PI_NODE_LOOKALIKE = 'COMMENT_AS_PI_NODE_LOOKALIKE'; 4558 4559 /** 4560 * Indicates that a comment was created when encountering invalid 4561 * HTML input, a so-called "bogus comment." 4562 * 4563 * Example: 4564 * 4565 * <?nothing special> 4566 * <!{nothing special}> 4567 * 4568 * @since 6.5.0 4569 */ 4570 const COMMENT_AS_INVALID_HTML = 'COMMENT_AS_INVALID_HTML'; 4571 4572 /** 4573 * No-quirks mode document compatibility mode. 4574 * 4575 * > In no-quirks mode, the behavior is (hopefully) the desired behavior 4576 * > described by the modern HTML and CSS specifications. 4577 * 4578 * @see self::$compat_mode 4579 * @see https://developer.mozilla.org/en-US/docs/Web/HTML/Quirks_Mode_and_Standards_Mode 4580 * 4581 * @since 6.7.0 4582 * 4583 * @var string 4584 */ 4585 const NO_QUIRKS_MODE = 'no-quirks-mode'; 4586 4587 /** 4588 * Quirks mode document compatibility mode. 4589 * 4590 * > In quirks mode, layout emulates behavior in Navigator 4 and Internet 4591 * > Explorer 5. This is essential in order to support websites that were 4592 * > built before the widespread adoption of web standards. 4593 * 4594 * @see self::$compat_mode 4595 * @see https://developer.mozilla.org/en-US/docs/Web/HTML/Quirks_Mode_and_Standards_Mode 4596 * 4597 * @since 6.7.0 4598 * 4599 * @var string 4600 */ 4601 const QUIRKS_MODE = 'quirks-mode'; 4602 4603 /** 4604 * Indicates that a span of text may contain any combination of significant 4605 * kinds of characters: NULL bytes, whitespace, and others. 4606 * 4607 * @see self::$text_node_classification 4608 * @see self::subdivide_text_appropriately 4609 * 4610 * @since 6.7.0 4611 */ 4612 const TEXT_IS_GENERIC = 'TEXT_IS_GENERIC'; 4613 4614 /** 4615 * Indicates that a span of text comprises a sequence only of NULL bytes. 4616 * 4617 * @see self::$text_node_classification 4618 * @see self::subdivide_text_appropriately 4619 * 4620 * @since 6.7.0 4621 */ 4622 const TEXT_IS_NULL_SEQUENCE = 'TEXT_IS_NULL_SEQUENCE'; 4623 4624 /** 4625 * Indicates that a span of decoded text comprises only whitespace. 4626 * 4627 * @see self::$text_node_classification 4628 * @see self::subdivide_text_appropriately 4629 * 4630 * @since 6.7.0 4631 */ 4632 const TEXT_IS_WHITESPACE = 'TEXT_IS_WHITESPACE'; 4633 }
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