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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 * For all script states a "-->" transitions 1501 * back into the normal unescaped script mode, 1502 * even if that's the current state. 1503 */ 1504 if ( 1505 $at + 2 < $doc_length && 1506 '-' === $html[ $at ] && 1507 '-' === $html[ $at + 1 ] && 1508 '>' === $html[ $at + 2 ] 1509 ) { 1510 $at += 3; 1511 $state = 'unescaped'; 1512 continue; 1513 } 1514 1515 if ( $at + 1 >= $doc_length ) { 1516 return false; 1517 } 1518 1519 /* 1520 * Everything of interest past here starts with "<". 1521 * Check this character and advance position regardless. 1522 */ 1523 if ( '<' !== $html[ $at++ ] ) { 1524 continue; 1525 } 1526 1527 /* 1528 * Unlike with "-->", the "<!--" only transitions 1529 * into the escaped mode if not already there. 1530 * 1531 * Inside the escaped modes it will be ignored; and 1532 * should never break out of the double-escaped 1533 * mode and back into the escaped mode. 1534 * 1535 * While this requires a mode change, it does not 1536 * impact the parsing otherwise, so continue 1537 * parsing after updating the state. 1538 */ 1539 if ( 1540 $at + 2 < $doc_length && 1541 '!' === $html[ $at ] && 1542 '-' === $html[ $at + 1 ] && 1543 '-' === $html[ $at + 2 ] 1544 ) { 1545 $at += 3; 1546 $state = 'unescaped' === $state ? 'escaped' : $state; 1547 continue; 1548 } 1549 1550 if ( '/' === $html[ $at ] ) { 1551 $closer_potentially_starts_at = $at - 1; 1552 $is_closing = true; 1553 ++$at; 1554 } else { 1555 $is_closing = false; 1556 } 1557 1558 /* 1559 * At this point the only remaining state-changes occur with the 1560 * <script> and </script> tags; unless one of these appears next, 1561 * proceed scanning to the next potential token in the text. 1562 */ 1563 if ( ! ( 1564 $at + 6 < $doc_length && 1565 ( 's' === $html[ $at ] || 'S' === $html[ $at ] ) && 1566 ( 'c' === $html[ $at + 1 ] || 'C' === $html[ $at + 1 ] ) && 1567 ( 'r' === $html[ $at + 2 ] || 'R' === $html[ $at + 2 ] ) && 1568 ( 'i' === $html[ $at + 3 ] || 'I' === $html[ $at + 3 ] ) && 1569 ( 'p' === $html[ $at + 4 ] || 'P' === $html[ $at + 4 ] ) && 1570 ( 't' === $html[ $at + 5 ] || 'T' === $html[ $at + 5 ] ) 1571 ) ) { 1572 ++$at; 1573 continue; 1574 } 1575 1576 /* 1577 * Ensure that the script tag terminates to avoid matching on 1578 * substrings of a non-match. For example, the sequence 1579 * "<script123" should not end a script region even though 1580 * "<script" is found within the text. 1581 */ 1582 if ( $at + 6 >= $doc_length ) { 1583 continue; 1584 } 1585 $at += 6; 1586 $c = $html[ $at ]; 1587 if ( ' ' !== $c && "\t" !== $c && "\r" !== $c && "\n" !== $c && '/' !== $c && '>' !== $c ) { 1588 ++$at; 1589 continue; 1590 } 1591 1592 if ( 'escaped' === $state && ! $is_closing ) { 1593 $state = 'double-escaped'; 1594 continue; 1595 } 1596 1597 if ( 'double-escaped' === $state && $is_closing ) { 1598 $state = 'escaped'; 1599 continue; 1600 } 1601 1602 if ( $is_closing ) { 1603 $this->bytes_already_parsed = $closer_potentially_starts_at; 1604 $this->tag_name_starts_at = $closer_potentially_starts_at; 1605 if ( $this->bytes_already_parsed >= $doc_length ) { 1606 return false; 1607 } 1608 1609 while ( $this->parse_next_attribute() ) { 1610 continue; 1611 } 1612 1613 if ( $this->bytes_already_parsed >= $doc_length ) { 1614 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 1615 1616 return false; 1617 } 1618 1619 if ( '>' === $html[ $this->bytes_already_parsed ] ) { 1620 ++$this->bytes_already_parsed; 1621 return true; 1622 } 1623 } 1624 1625 ++$at; 1626 } 1627 1628 return false; 1629 } 1630 1631 /** 1632 * Parses the next tag. 1633 * 1634 * This will find and start parsing the next tag, including 1635 * the opening `<`, the potential closer `/`, and the tag 1636 * name. It does not parse the attributes or scan to the 1637 * closing `>`; these are left for other methods. 1638 * 1639 * @since 6.2.0 1640 * @since 6.2.1 Support abruptly-closed comments, invalid-tag-closer-comments, and empty elements. 1641 * 1642 * @return bool Whether a tag was found before the end of the document. 1643 */ 1644 private function parse_next_tag(): bool { 1645 $this->after_tag(); 1646 1647 $html = $this->html; 1648 $doc_length = strlen( $html ); 1649 $was_at = $this->bytes_already_parsed; 1650 $at = $was_at; 1651 1652 while ( $at < $doc_length ) { 1653 $at = strpos( $html, '<', $at ); 1654 if ( false === $at ) { 1655 break; 1656 } 1657 1658 if ( $at > $was_at ) { 1659 /* 1660 * A "<" normally starts a new HTML tag or syntax token, but in cases where the 1661 * following character can't produce a valid token, the "<" is instead treated 1662 * as plaintext and the parser should skip over it. This avoids a problem when 1663 * following earlier practices of typing emoji with text, e.g. "<3". This 1664 * should be a heart, not a tag. It's supposed to be rendered, not hidden. 1665 * 1666 * At this point the parser checks if this is one of those cases and if it is 1667 * will continue searching for the next "<" in search of a token boundary. 1668 * 1669 * @see https://html.spec.whatwg.org/#tag-open-state 1670 */ 1671 if ( 1 !== strspn( $html, '!/?abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ', $at + 1, 1 ) ) { 1672 ++$at; 1673 continue; 1674 } 1675 1676 $this->parser_state = self::STATE_TEXT_NODE; 1677 $this->token_starts_at = $was_at; 1678 $this->token_length = $at - $was_at; 1679 $this->text_starts_at = $was_at; 1680 $this->text_length = $this->token_length; 1681 $this->bytes_already_parsed = $at; 1682 return true; 1683 } 1684 1685 $this->token_starts_at = $at; 1686 1687 if ( $at + 1 < $doc_length && '/' === $this->html[ $at + 1 ] ) { 1688 $this->is_closing_tag = true; 1689 ++$at; 1690 } else { 1691 $this->is_closing_tag = false; 1692 } 1693 1694 /* 1695 * HTML tag names must start with [a-zA-Z] otherwise they are not tags. 1696 * For example, "<3" is rendered as text, not a tag opener. If at least 1697 * one letter follows the "<" then _it is_ a tag, but if the following 1698 * character is anything else it _is not a tag_. 1699 * 1700 * It's not uncommon to find non-tags starting with `<` in an HTML 1701 * document, so it's good for performance to make this pre-check before 1702 * continuing to attempt to parse a tag name. 1703 * 1704 * Reference: 1705 * * https://html.spec.whatwg.org/multipage/parsing.html#data-state 1706 * * https://html.spec.whatwg.org/multipage/parsing.html#tag-open-state 1707 */ 1708 $tag_name_prefix_length = strspn( $html, 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ', $at + 1 ); 1709 if ( $tag_name_prefix_length > 0 ) { 1710 ++$at; 1711 $this->parser_state = self::STATE_MATCHED_TAG; 1712 $this->tag_name_starts_at = $at; 1713 $this->tag_name_length = $tag_name_prefix_length + strcspn( $html, " \t\f\r\n/>", $at + $tag_name_prefix_length ); 1714 $this->bytes_already_parsed = $at + $this->tag_name_length; 1715 return true; 1716 } 1717 1718 /* 1719 * Abort if no tag is found before the end of 1720 * the document. There is nothing left to parse. 1721 */ 1722 if ( $at + 1 >= $doc_length ) { 1723 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 1724 1725 return false; 1726 } 1727 1728 /* 1729 * `<!` transitions to markup declaration open state 1730 * https://html.spec.whatwg.org/multipage/parsing.html#markup-declaration-open-state 1731 */ 1732 if ( ! $this->is_closing_tag && '!' === $html[ $at + 1 ] ) { 1733 /* 1734 * `<!--` transitions to a comment state – apply further comment rules. 1735 * https://html.spec.whatwg.org/multipage/parsing.html#tag-open-state 1736 */ 1737 if ( 0 === substr_compare( $html, '--', $at + 2, 2 ) ) { 1738 $closer_at = $at + 4; 1739 // If it's not possible to close the comment then there is nothing more to scan. 1740 if ( $doc_length <= $closer_at ) { 1741 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 1742 1743 return false; 1744 } 1745 1746 // Abruptly-closed empty comments are a sequence of dashes followed by `>`. 1747 $span_of_dashes = strspn( $html, '-', $closer_at ); 1748 if ( '>' === $html[ $closer_at + $span_of_dashes ] ) { 1749 /* 1750 * @todo When implementing `set_modifiable_text()` ensure that updates to this token 1751 * don't break the syntax for short comments, e.g. `<!--->`. Unlike other comment 1752 * and bogus comment syntax, these leave no clear insertion point for text and 1753 * they need to be modified specially in order to contain text. E.g. to store 1754 * `?` as the modifiable text, the `<!--->` needs to become `<!--?-->`, which 1755 * involves inserting an additional `-` into the token after the modifiable text. 1756 */ 1757 $this->parser_state = self::STATE_COMMENT; 1758 $this->comment_type = self::COMMENT_AS_ABRUPTLY_CLOSED_COMMENT; 1759 $this->token_length = $closer_at + $span_of_dashes + 1 - $this->token_starts_at; 1760 1761 // Only provide modifiable text if the token is long enough to contain it. 1762 if ( $span_of_dashes >= 2 ) { 1763 $this->comment_type = self::COMMENT_AS_HTML_COMMENT; 1764 $this->text_starts_at = $this->token_starts_at + 4; 1765 $this->text_length = $span_of_dashes - 2; 1766 } 1767 1768 $this->bytes_already_parsed = $closer_at + $span_of_dashes + 1; 1769 return true; 1770 } 1771 1772 /* 1773 * Comments may be closed by either a --> or an invalid --!>. 1774 * The first occurrence closes the comment. 1775 * 1776 * See https://html.spec.whatwg.org/#parse-error-incorrectly-closed-comment 1777 */ 1778 --$closer_at; // Pre-increment inside condition below reduces risk of accidental infinite looping. 1779 while ( ++$closer_at < $doc_length ) { 1780 $closer_at = strpos( $html, '--', $closer_at ); 1781 if ( false === $closer_at ) { 1782 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 1783 1784 return false; 1785 } 1786 1787 if ( $closer_at + 2 < $doc_length && '>' === $html[ $closer_at + 2 ] ) { 1788 $this->parser_state = self::STATE_COMMENT; 1789 $this->comment_type = self::COMMENT_AS_HTML_COMMENT; 1790 $this->token_length = $closer_at + 3 - $this->token_starts_at; 1791 $this->text_starts_at = $this->token_starts_at + 4; 1792 $this->text_length = $closer_at - $this->text_starts_at; 1793 $this->bytes_already_parsed = $closer_at + 3; 1794 return true; 1795 } 1796 1797 if ( 1798 $closer_at + 3 < $doc_length && 1799 '!' === $html[ $closer_at + 2 ] && 1800 '>' === $html[ $closer_at + 3 ] 1801 ) { 1802 $this->parser_state = self::STATE_COMMENT; 1803 $this->comment_type = self::COMMENT_AS_HTML_COMMENT; 1804 $this->token_length = $closer_at + 4 - $this->token_starts_at; 1805 $this->text_starts_at = $this->token_starts_at + 4; 1806 $this->text_length = $closer_at - $this->text_starts_at; 1807 $this->bytes_already_parsed = $closer_at + 4; 1808 return true; 1809 } 1810 } 1811 } 1812 1813 /* 1814 * `<!DOCTYPE` transitions to DOCTYPE state – skip to the nearest > 1815 * These are ASCII-case-insensitive. 1816 * https://html.spec.whatwg.org/multipage/parsing.html#tag-open-state 1817 */ 1818 if ( 1819 $doc_length > $at + 8 && 1820 ( 'D' === $html[ $at + 2 ] || 'd' === $html[ $at + 2 ] ) && 1821 ( 'O' === $html[ $at + 3 ] || 'o' === $html[ $at + 3 ] ) && 1822 ( 'C' === $html[ $at + 4 ] || 'c' === $html[ $at + 4 ] ) && 1823 ( 'T' === $html[ $at + 5 ] || 't' === $html[ $at + 5 ] ) && 1824 ( 'Y' === $html[ $at + 6 ] || 'y' === $html[ $at + 6 ] ) && 1825 ( 'P' === $html[ $at + 7 ] || 'p' === $html[ $at + 7 ] ) && 1826 ( 'E' === $html[ $at + 8 ] || 'e' === $html[ $at + 8 ] ) 1827 ) { 1828 $closer_at = strpos( $html, '>', $at + 9 ); 1829 if ( false === $closer_at ) { 1830 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 1831 1832 return false; 1833 } 1834 1835 $this->parser_state = self::STATE_DOCTYPE; 1836 $this->token_length = $closer_at + 1 - $this->token_starts_at; 1837 $this->text_starts_at = $this->token_starts_at + 9; 1838 $this->text_length = $closer_at - $this->text_starts_at; 1839 $this->bytes_already_parsed = $closer_at + 1; 1840 return true; 1841 } 1842 1843 if ( 1844 'html' !== $this->parsing_namespace && 1845 strlen( $html ) > $at + 8 && 1846 '[' === $html[ $at + 2 ] && 1847 'C' === $html[ $at + 3 ] && 1848 'D' === $html[ $at + 4 ] && 1849 'A' === $html[ $at + 5 ] && 1850 'T' === $html[ $at + 6 ] && 1851 'A' === $html[ $at + 7 ] && 1852 '[' === $html[ $at + 8 ] 1853 ) { 1854 $closer_at = strpos( $html, ']]>', $at + 9 ); 1855 if ( false === $closer_at ) { 1856 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 1857 1858 return false; 1859 } 1860 1861 $this->parser_state = self::STATE_CDATA_NODE; 1862 $this->text_starts_at = $at + 9; 1863 $this->text_length = $closer_at - $this->text_starts_at; 1864 $this->token_length = $closer_at + 3 - $this->token_starts_at; 1865 $this->bytes_already_parsed = $closer_at + 3; 1866 return true; 1867 } 1868 1869 /* 1870 * Anything else here is an incorrectly-opened comment and transitions 1871 * to the bogus comment state - skip to the nearest >. If no closer is 1872 * found then the HTML was truncated inside the markup declaration. 1873 */ 1874 $closer_at = strpos( $html, '>', $at + 1 ); 1875 if ( false === $closer_at ) { 1876 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 1877 1878 return false; 1879 } 1880 1881 $this->parser_state = self::STATE_COMMENT; 1882 $this->comment_type = self::COMMENT_AS_INVALID_HTML; 1883 $this->token_length = $closer_at + 1 - $this->token_starts_at; 1884 $this->text_starts_at = $this->token_starts_at + 2; 1885 $this->text_length = $closer_at - $this->text_starts_at; 1886 $this->bytes_already_parsed = $closer_at + 1; 1887 1888 /* 1889 * Identify nodes that would be CDATA if HTML had CDATA sections. 1890 * 1891 * This section must occur after identifying the bogus comment end 1892 * because in an HTML parser it will span to the nearest `>`, even 1893 * if there's no `]]>` as would be required in an XML document. It 1894 * is therefore not possible to parse a CDATA section containing 1895 * a `>` in the HTML syntax. 1896 * 1897 * Inside foreign elements there is a discrepancy between browsers 1898 * and the specification on this. 1899 * 1900 * @todo Track whether the Tag Processor is inside a foreign element 1901 * and require the proper closing `]]>` in those cases. 1902 */ 1903 if ( 1904 $this->token_length >= 10 && 1905 '[' === $html[ $this->token_starts_at + 2 ] && 1906 'C' === $html[ $this->token_starts_at + 3 ] && 1907 'D' === $html[ $this->token_starts_at + 4 ] && 1908 'A' === $html[ $this->token_starts_at + 5 ] && 1909 'T' === $html[ $this->token_starts_at + 6 ] && 1910 'A' === $html[ $this->token_starts_at + 7 ] && 1911 '[' === $html[ $this->token_starts_at + 8 ] && 1912 ']' === $html[ $closer_at - 1 ] && 1913 ']' === $html[ $closer_at - 2 ] 1914 ) { 1915 $this->parser_state = self::STATE_COMMENT; 1916 $this->comment_type = self::COMMENT_AS_CDATA_LOOKALIKE; 1917 $this->text_starts_at += 7; 1918 $this->text_length -= 9; 1919 } 1920 1921 return true; 1922 } 1923 1924 /* 1925 * </> is a missing end tag name, which is ignored. 1926 * 1927 * This was also known as the "presumptuous empty tag" 1928 * in early discussions as it was proposed to close 1929 * the nearest previous opening tag. 1930 * 1931 * See https://html.spec.whatwg.org/#parse-error-missing-end-tag-name 1932 */ 1933 if ( '>' === $html[ $at + 1 ] ) { 1934 // `<>` is interpreted as plaintext. 1935 if ( ! $this->is_closing_tag ) { 1936 ++$at; 1937 continue; 1938 } 1939 1940 $this->parser_state = self::STATE_PRESUMPTUOUS_TAG; 1941 $this->token_length = $at + 2 - $this->token_starts_at; 1942 $this->bytes_already_parsed = $at + 2; 1943 return true; 1944 } 1945 1946 /* 1947 * `<?` transitions to a bogus comment state – skip to the nearest > 1948 * See https://html.spec.whatwg.org/multipage/parsing.html#tag-open-state 1949 */ 1950 if ( ! $this->is_closing_tag && '?' === $html[ $at + 1 ] ) { 1951 $closer_at = strpos( $html, '>', $at + 2 ); 1952 if ( false === $closer_at ) { 1953 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 1954 1955 return false; 1956 } 1957 1958 $this->parser_state = self::STATE_COMMENT; 1959 $this->comment_type = self::COMMENT_AS_INVALID_HTML; 1960 $this->token_length = $closer_at + 1 - $this->token_starts_at; 1961 $this->text_starts_at = $this->token_starts_at + 2; 1962 $this->text_length = $closer_at - $this->text_starts_at; 1963 $this->bytes_already_parsed = $closer_at + 1; 1964 1965 /* 1966 * Identify a Processing Instruction node were HTML to have them. 1967 * 1968 * This section must occur after identifying the bogus comment end 1969 * because in an HTML parser it will span to the nearest `>`, even 1970 * if there's no `?>` as would be required in an XML document. It 1971 * is therefore not possible to parse a Processing Instruction node 1972 * containing a `>` in the HTML syntax. 1973 * 1974 * XML allows for more target names, but this code only identifies 1975 * those with ASCII-representable target names. This means that it 1976 * may identify some Processing Instruction nodes as bogus comments, 1977 * but it will not misinterpret the HTML structure. By limiting the 1978 * identification to these target names the Tag Processor can avoid 1979 * the need to start parsing UTF-8 sequences. 1980 * 1981 * > NameStartChar ::= ":" | [A-Z] | "_" | [a-z] | [#xC0-#xD6] | [#xD8-#xF6] | [#xF8-#x2FF] | 1982 * [#x370-#x37D] | [#x37F-#x1FFF] | [#x200C-#x200D] | [#x2070-#x218F] | 1983 * [#x2C00-#x2FEF] | [#x3001-#xD7FF] | [#xF900-#xFDCF] | [#xFDF0-#xFFFD] | 1984 * [#x10000-#xEFFFF] 1985 * > NameChar ::= NameStartChar | "-" | "." | [0-9] | #xB7 | [#x0300-#x036F] | [#x203F-#x2040] 1986 * 1987 * @todo Processing instruction nodes in SGML may contain any kind of markup. XML defines a 1988 * special case with `<?xml ... ?>` syntax, but the `?` is part of the bogus comment. 1989 * 1990 * @see https://www.w3.org/TR/2006/REC-xml11-20060816/#NT-PITarget 1991 */ 1992 if ( $this->token_length >= 5 && '?' === $html[ $closer_at - 1 ] ) { 1993 $comment_text = substr( $html, $this->token_starts_at + 2, $this->token_length - 4 ); 1994 $pi_target_length = strspn( $comment_text, 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ:_' ); 1995 1996 if ( 0 < $pi_target_length ) { 1997 $pi_target_length += strspn( $comment_text, 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789:_-.', $pi_target_length ); 1998 1999 $this->comment_type = self::COMMENT_AS_PI_NODE_LOOKALIKE; 2000 $this->tag_name_starts_at = $this->token_starts_at + 2; 2001 $this->tag_name_length = $pi_target_length; 2002 $this->text_starts_at += $pi_target_length; 2003 $this->text_length -= $pi_target_length + 1; 2004 } 2005 } 2006 2007 return true; 2008 } 2009 2010 /* 2011 * If a non-alpha starts the tag name in a tag closer it's a comment. 2012 * Find the first `>`, which closes the comment. 2013 * 2014 * This parser classifies these particular comments as special "funky comments" 2015 * which are made available for further processing. 2016 * 2017 * See https://html.spec.whatwg.org/#parse-error-invalid-first-character-of-tag-name 2018 */ 2019 if ( $this->is_closing_tag ) { 2020 // No chance of finding a closer. 2021 if ( $at + 3 > $doc_length ) { 2022 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 2023 2024 return false; 2025 } 2026 2027 $closer_at = strpos( $html, '>', $at + 2 ); 2028 if ( false === $closer_at ) { 2029 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 2030 2031 return false; 2032 } 2033 2034 $this->parser_state = self::STATE_FUNKY_COMMENT; 2035 $this->token_length = $closer_at + 1 - $this->token_starts_at; 2036 $this->text_starts_at = $this->token_starts_at + 2; 2037 $this->text_length = $closer_at - $this->text_starts_at; 2038 $this->bytes_already_parsed = $closer_at + 1; 2039 return true; 2040 } 2041 2042 ++$at; 2043 } 2044 2045 /* 2046 * This does not imply an incomplete parse; it indicates that there 2047 * can be nothing left in the document other than a #text node. 2048 */ 2049 $this->parser_state = self::STATE_TEXT_NODE; 2050 $this->token_starts_at = $was_at; 2051 $this->token_length = $doc_length - $was_at; 2052 $this->text_starts_at = $was_at; 2053 $this->text_length = $this->token_length; 2054 $this->bytes_already_parsed = $doc_length; 2055 return true; 2056 } 2057 2058 /** 2059 * Parses the next attribute. 2060 * 2061 * @since 6.2.0 2062 * 2063 * @return bool Whether an attribute was found before the end of the document. 2064 */ 2065 private function parse_next_attribute(): bool { 2066 $doc_length = strlen( $this->html ); 2067 2068 // Skip whitespace and slashes. 2069 $this->bytes_already_parsed += strspn( $this->html, " \t\f\r\n/", $this->bytes_already_parsed ); 2070 if ( $this->bytes_already_parsed >= $doc_length ) { 2071 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 2072 2073 return false; 2074 } 2075 2076 /* 2077 * Treat the equal sign as a part of the attribute 2078 * name if it is the first encountered byte. 2079 * 2080 * @see https://html.spec.whatwg.org/multipage/parsing.html#before-attribute-name-state 2081 */ 2082 $name_length = '=' === $this->html[ $this->bytes_already_parsed ] 2083 ? 1 + strcspn( $this->html, "=/> \t\f\r\n", $this->bytes_already_parsed + 1 ) 2084 : strcspn( $this->html, "=/> \t\f\r\n", $this->bytes_already_parsed ); 2085 2086 // No attribute, just tag closer. 2087 if ( 0 === $name_length || $this->bytes_already_parsed + $name_length >= $doc_length ) { 2088 return false; 2089 } 2090 2091 $attribute_start = $this->bytes_already_parsed; 2092 $attribute_name = substr( $this->html, $attribute_start, $name_length ); 2093 $this->bytes_already_parsed += $name_length; 2094 if ( $this->bytes_already_parsed >= $doc_length ) { 2095 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 2096 2097 return false; 2098 } 2099 2100 $this->skip_whitespace(); 2101 if ( $this->bytes_already_parsed >= $doc_length ) { 2102 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 2103 2104 return false; 2105 } 2106 2107 $has_value = '=' === $this->html[ $this->bytes_already_parsed ]; 2108 if ( $has_value ) { 2109 ++$this->bytes_already_parsed; 2110 $this->skip_whitespace(); 2111 if ( $this->bytes_already_parsed >= $doc_length ) { 2112 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 2113 2114 return false; 2115 } 2116 2117 switch ( $this->html[ $this->bytes_already_parsed ] ) { 2118 case "'": 2119 case '"': 2120 $quote = $this->html[ $this->bytes_already_parsed ]; 2121 $value_start = $this->bytes_already_parsed + 1; 2122 $end_quote_at = strpos( $this->html, $quote, $value_start ); 2123 $end_quote_at = false === $end_quote_at ? $doc_length : $end_quote_at; 2124 $value_length = $end_quote_at - $value_start; 2125 $attribute_end = $end_quote_at + 1; 2126 $this->bytes_already_parsed = $attribute_end; 2127 break; 2128 2129 default: 2130 $value_start = $this->bytes_already_parsed; 2131 $value_length = strcspn( $this->html, "> \t\f\r\n", $value_start ); 2132 $attribute_end = $value_start + $value_length; 2133 $this->bytes_already_parsed = $attribute_end; 2134 } 2135 } else { 2136 $value_start = $this->bytes_already_parsed; 2137 $value_length = 0; 2138 $attribute_end = $attribute_start + $name_length; 2139 } 2140 2141 if ( $attribute_end >= $doc_length ) { 2142 $this->parser_state = self::STATE_INCOMPLETE_INPUT; 2143 2144 return false; 2145 } 2146 2147 if ( $this->is_closing_tag ) { 2148 return true; 2149 } 2150 2151 /* 2152 * > There must never be two or more attributes on 2153 * > the same start tag whose names are an ASCII 2154 * > case-insensitive match for each other. 2155 * - HTML 5 spec 2156 * 2157 * @see https://html.spec.whatwg.org/multipage/syntax.html#attributes-2:ascii-case-insensitive 2158 */ 2159 $comparable_name = strtolower( $attribute_name ); 2160 2161 // If an attribute is listed many times, only use the first declaration and ignore the rest. 2162 if ( ! isset( $this->attributes[ $comparable_name ] ) ) { 2163 $this->attributes[ $comparable_name ] = new WP_HTML_Attribute_Token( 2164 $attribute_name, 2165 $value_start, 2166 $value_length, 2167 $attribute_start, 2168 $attribute_end - $attribute_start, 2169 ! $has_value 2170 ); 2171 2172 return true; 2173 } 2174 2175 /* 2176 * Track the duplicate attributes so if we remove it, all disappear together. 2177 * 2178 * While `$this->duplicated_attributes` could always be stored as an `array()`, 2179 * which would simplify the logic here, storing a `null` and only allocating 2180 * an array when encountering duplicates avoids needless allocations in the 2181 * normative case of parsing tags with no duplicate attributes. 2182 */ 2183 $duplicate_span = new WP_HTML_Span( $attribute_start, $attribute_end - $attribute_start ); 2184 if ( null === $this->duplicate_attributes ) { 2185 $this->duplicate_attributes = array( $comparable_name => array( $duplicate_span ) ); 2186 } elseif ( ! isset( $this->duplicate_attributes[ $comparable_name ] ) ) { 2187 $this->duplicate_attributes[ $comparable_name ] = array( $duplicate_span ); 2188 } else { 2189 $this->duplicate_attributes[ $comparable_name ][] = $duplicate_span; 2190 } 2191 2192 return true; 2193 } 2194 2195 /** 2196 * Move the internal cursor past any immediate successive whitespace. 2197 * 2198 * @since 6.2.0 2199 */ 2200 private function skip_whitespace(): void { 2201 $this->bytes_already_parsed += strspn( $this->html, " \t\f\r\n", $this->bytes_already_parsed ); 2202 } 2203 2204 /** 2205 * Applies attribute updates and cleans up once a tag is fully parsed. 2206 * 2207 * @since 6.2.0 2208 */ 2209 private function after_tag(): void { 2210 /* 2211 * There could be lexical updates enqueued for an attribute that 2212 * also exists on the next tag. In order to avoid conflating the 2213 * attributes across the two tags, lexical updates with names 2214 * need to be flushed to raw lexical updates. 2215 */ 2216 $this->class_name_updates_to_attributes_updates(); 2217 2218 /* 2219 * Purge updates if there are too many. The actual count isn't 2220 * scientific, but a few values from 100 to a few thousand were 2221 * tests to find a practically-useful limit. 2222 * 2223 * If the update queue grows too big, then the Tag Processor 2224 * will spend more time iterating through them and lose the 2225 * efficiency gains of deferring applying them. 2226 */ 2227 if ( 1000 < count( $this->lexical_updates ) ) { 2228 $this->get_updated_html(); 2229 } 2230 2231 foreach ( $this->lexical_updates as $name => $update ) { 2232 /* 2233 * Any updates appearing after the cursor should be applied 2234 * before proceeding, otherwise they may be overlooked. 2235 */ 2236 if ( $update->start >= $this->bytes_already_parsed ) { 2237 $this->get_updated_html(); 2238 break; 2239 } 2240 2241 if ( is_int( $name ) ) { 2242 continue; 2243 } 2244 2245 $this->lexical_updates[] = $update; 2246 unset( $this->lexical_updates[ $name ] ); 2247 } 2248 2249 $this->token_starts_at = null; 2250 $this->token_length = null; 2251 $this->tag_name_starts_at = null; 2252 $this->tag_name_length = null; 2253 $this->text_starts_at = 0; 2254 $this->text_length = 0; 2255 $this->is_closing_tag = null; 2256 $this->attributes = array(); 2257 $this->comment_type = null; 2258 $this->text_node_classification = self::TEXT_IS_GENERIC; 2259 $this->duplicate_attributes = null; 2260 } 2261 2262 /** 2263 * Converts class name updates into tag attributes updates 2264 * (they are accumulated in different data formats for performance). 2265 * 2266 * @since 6.2.0 2267 * 2268 * @see WP_HTML_Tag_Processor::$lexical_updates 2269 * @see WP_HTML_Tag_Processor::$classname_updates 2270 */ 2271 private function class_name_updates_to_attributes_updates(): void { 2272 if ( count( $this->classname_updates ) === 0 ) { 2273 return; 2274 } 2275 2276 $existing_class = $this->get_enqueued_attribute_value( 'class' ); 2277 if ( null === $existing_class || true === $existing_class ) { 2278 $existing_class = ''; 2279 } 2280 2281 if ( false === $existing_class && isset( $this->attributes['class'] ) ) { 2282 $existing_class = substr( 2283 $this->html, 2284 $this->attributes['class']->value_starts_at, 2285 $this->attributes['class']->value_length 2286 ); 2287 } 2288 2289 if ( false === $existing_class ) { 2290 $existing_class = ''; 2291 } 2292 2293 /** 2294 * Updated "class" attribute value. 2295 * 2296 * This is incrementally built while scanning through the existing class 2297 * attribute, skipping removed classes on the way, and then appending 2298 * added classes at the end. Only when finished processing will the 2299 * value contain the final new value. 2300 2301 * @var string $class 2302 */ 2303 $class = ''; 2304 2305 /** 2306 * Tracks the cursor position in the existing 2307 * class attribute value while parsing. 2308 * 2309 * @var int $at 2310 */ 2311 $at = 0; 2312 2313 /** 2314 * Indicates if there's any need to modify the existing class attribute. 2315 * 2316 * If a call to `add_class()` and `remove_class()` wouldn't impact 2317 * the `class` attribute value then there's no need to rebuild it. 2318 * For example, when adding a class that's already present or 2319 * removing one that isn't. 2320 * 2321 * This flag enables a performance optimization when none of the enqueued 2322 * class updates would impact the `class` attribute; namely, that the 2323 * processor can continue without modifying the input document, as if 2324 * none of the `add_class()` or `remove_class()` calls had been made. 2325 * 2326 * This flag is set upon the first change that requires a string update. 2327 * 2328 * @var bool $modified 2329 */ 2330 $modified = false; 2331 2332 $seen = array(); 2333 $to_remove = array(); 2334 $is_quirks = self::QUIRKS_MODE === $this->compat_mode; 2335 if ( $is_quirks ) { 2336 foreach ( $this->classname_updates as $updated_name => $action ) { 2337 if ( self::REMOVE_CLASS === $action ) { 2338 $to_remove[] = strtolower( $updated_name ); 2339 } 2340 } 2341 } else { 2342 foreach ( $this->classname_updates as $updated_name => $action ) { 2343 if ( self::REMOVE_CLASS === $action ) { 2344 $to_remove[] = $updated_name; 2345 } 2346 } 2347 } 2348 2349 // Remove unwanted classes by only copying the new ones. 2350 $existing_class_length = strlen( $existing_class ); 2351 while ( $at < $existing_class_length ) { 2352 // Skip to the first non-whitespace character. 2353 $ws_at = $at; 2354 $ws_length = strspn( $existing_class, " \t\f\r\n", $ws_at ); 2355 $at += $ws_length; 2356 2357 // Capture the class name – it's everything until the next whitespace. 2358 $name_length = strcspn( $existing_class, " \t\f\r\n", $at ); 2359 if ( 0 === $name_length ) { 2360 // If no more class names are found then that's the end. 2361 break; 2362 } 2363 2364 $name = substr( $existing_class, $at, $name_length ); 2365 $comparable_class_name = $is_quirks ? strtolower( $name ) : $name; 2366 $at += $name_length; 2367 2368 // If this class is marked for removal, remove it and move on to the next one. 2369 if ( in_array( $comparable_class_name, $to_remove, true ) ) { 2370 $modified = true; 2371 continue; 2372 } 2373 2374 // If a class has already been seen then skip it; it should not be added twice. 2375 if ( in_array( $comparable_class_name, $seen, true ) ) { 2376 continue; 2377 } 2378 2379 $seen[] = $comparable_class_name; 2380 2381 /* 2382 * Otherwise, append it to the new "class" attribute value. 2383 * 2384 * There are options for handling whitespace between tags. 2385 * Preserving the existing whitespace produces fewer changes 2386 * to the HTML content and should clarify the before/after 2387 * content when debugging the modified output. 2388 * 2389 * This approach contrasts normalizing the inter-class 2390 * whitespace to a single space, which might appear cleaner 2391 * in the output HTML but produce a noisier change. 2392 */ 2393 if ( '' !== $class ) { 2394 $class .= substr( $existing_class, $ws_at, $ws_length ); 2395 } 2396 $class .= $name; 2397 } 2398 2399 // Add new classes by appending those which haven't already been seen. 2400 foreach ( $this->classname_updates as $name => $operation ) { 2401 $comparable_name = $is_quirks ? strtolower( $name ) : $name; 2402 if ( self::ADD_CLASS === $operation && ! in_array( $comparable_name, $seen, true ) ) { 2403 $modified = true; 2404 2405 $class .= strlen( $class ) > 0 ? ' ' : ''; 2406 $class .= $name; 2407 } 2408 } 2409 2410 $this->classname_updates = array(); 2411 if ( ! $modified ) { 2412 return; 2413 } 2414 2415 if ( strlen( $class ) > 0 ) { 2416 $this->set_attribute( 'class', $class ); 2417 } else { 2418 $this->remove_attribute( 'class' ); 2419 } 2420 } 2421 2422 /** 2423 * Applies attribute updates to HTML document. 2424 * 2425 * @since 6.2.0 2426 * @since 6.2.1 Accumulates shift for internal cursor and passed pointer. 2427 * @since 6.3.0 Invalidate any bookmarks whose targets are overwritten. 2428 * 2429 * @param int $shift_this_point Accumulate and return shift for this position. 2430 * @return int How many bytes the given pointer moved in response to the updates. 2431 */ 2432 private function apply_attributes_updates( int $shift_this_point ): int { 2433 if ( ! count( $this->lexical_updates ) ) { 2434 return 0; 2435 } 2436 2437 $accumulated_shift_for_given_point = 0; 2438 2439 /* 2440 * Attribute updates can be enqueued in any order but updates 2441 * to the document must occur in lexical order; that is, each 2442 * replacement must be made before all others which follow it 2443 * at later string indices in the input document. 2444 * 2445 * Sorting avoid making out-of-order replacements which 2446 * can lead to mangled output, partially-duplicated 2447 * attributes, and overwritten attributes. 2448 */ 2449 usort( $this->lexical_updates, array( self::class, 'sort_start_ascending' ) ); 2450 2451 $bytes_already_copied = 0; 2452 $output_buffer = ''; 2453 foreach ( $this->lexical_updates as $diff ) { 2454 $shift = strlen( $diff->text ) - $diff->length; 2455 2456 // Adjust the cursor position by however much an update affects it. 2457 if ( $diff->start < $this->bytes_already_parsed ) { 2458 $this->bytes_already_parsed += $shift; 2459 } 2460 2461 // Accumulate shift of the given pointer within this function call. 2462 if ( $diff->start < $shift_this_point ) { 2463 $accumulated_shift_for_given_point += $shift; 2464 } 2465 2466 $output_buffer .= substr( $this->html, $bytes_already_copied, $diff->start - $bytes_already_copied ); 2467 $output_buffer .= $diff->text; 2468 $bytes_already_copied = $diff->start + $diff->length; 2469 } 2470 2471 $this->html = $output_buffer . substr( $this->html, $bytes_already_copied ); 2472 2473 /* 2474 * Adjust bookmark locations to account for how the text 2475 * replacements adjust offsets in the input document. 2476 */ 2477 foreach ( $this->bookmarks as $bookmark_name => $bookmark ) { 2478 $bookmark_end = $bookmark->start + $bookmark->length; 2479 2480 /* 2481 * Each lexical update which appears before the bookmark's endpoints 2482 * might shift the offsets for those endpoints. Loop through each change 2483 * and accumulate the total shift for each bookmark, then apply that 2484 * shift after tallying the full delta. 2485 */ 2486 $head_delta = 0; 2487 $tail_delta = 0; 2488 2489 foreach ( $this->lexical_updates as $diff ) { 2490 $diff_end = $diff->start + $diff->length; 2491 2492 if ( $bookmark->start < $diff->start && $bookmark_end < $diff->start ) { 2493 break; 2494 } 2495 2496 if ( $bookmark->start >= $diff->start && $bookmark_end < $diff_end ) { 2497 $this->release_bookmark( $bookmark_name ); 2498 continue 2; 2499 } 2500 2501 $delta = strlen( $diff->text ) - $diff->length; 2502 2503 if ( $bookmark->start >= $diff->start ) { 2504 $head_delta += $delta; 2505 } 2506 2507 if ( $bookmark_end >= $diff_end ) { 2508 $tail_delta += $delta; 2509 } 2510 } 2511 2512 $bookmark->start += $head_delta; 2513 $bookmark->length += $tail_delta - $head_delta; 2514 } 2515 2516 $this->lexical_updates = array(); 2517 2518 return $accumulated_shift_for_given_point; 2519 } 2520 2521 /** 2522 * Checks whether a bookmark with the given name exists. 2523 * 2524 * @since 6.3.0 2525 * 2526 * @param string $bookmark_name Name to identify a bookmark that potentially exists. 2527 * @return bool Whether that bookmark exists. 2528 */ 2529 public function has_bookmark( $bookmark_name ): bool { 2530 return array_key_exists( $bookmark_name, $this->bookmarks ); 2531 } 2532 2533 /** 2534 * Move the internal cursor in the Tag Processor to a given bookmark's location. 2535 * 2536 * In order to prevent accidental infinite loops, there's a 2537 * maximum limit on the number of times seek() can be called. 2538 * 2539 * @since 6.2.0 2540 * 2541 * @param string $bookmark_name Jump to the place in the document identified by this bookmark name. 2542 * @return bool Whether the internal cursor was successfully moved to the bookmark's location. 2543 */ 2544 public function seek( $bookmark_name ): bool { 2545 if ( ! array_key_exists( $bookmark_name, $this->bookmarks ) ) { 2546 _doing_it_wrong( 2547 __METHOD__, 2548 __( 'Unknown bookmark name.' ), 2549 '6.2.0' 2550 ); 2551 return false; 2552 } 2553 2554 $existing_bookmark = $this->bookmarks[ $bookmark_name ]; 2555 2556 if ( 2557 $this->token_starts_at === $existing_bookmark->start && 2558 $this->token_length === $existing_bookmark->length 2559 ) { 2560 return true; 2561 } 2562 2563 if ( ++$this->seek_count > static::MAX_SEEK_OPS ) { 2564 _doing_it_wrong( 2565 __METHOD__, 2566 __( 'Too many calls to seek() - this can lead to performance issues.' ), 2567 '6.2.0' 2568 ); 2569 return false; 2570 } 2571 2572 // Flush out any pending updates to the document. 2573 $this->get_updated_html(); 2574 2575 // Point this tag processor before the sought tag opener and consume it. 2576 $this->bytes_already_parsed = $this->bookmarks[ $bookmark_name ]->start; 2577 $this->parser_state = self::STATE_READY; 2578 return $this->next_token(); 2579 } 2580 2581 /** 2582 * Compare two WP_HTML_Text_Replacement objects. 2583 * 2584 * @since 6.2.0 2585 * 2586 * @param WP_HTML_Text_Replacement $a First attribute update. 2587 * @param WP_HTML_Text_Replacement $b Second attribute update. 2588 * @return int Comparison value for string order. 2589 */ 2590 private static function sort_start_ascending( WP_HTML_Text_Replacement $a, WP_HTML_Text_Replacement $b ): int { 2591 $by_start = $a->start - $b->start; 2592 if ( 0 !== $by_start ) { 2593 return $by_start; 2594 } 2595 2596 $by_text = isset( $a->text, $b->text ) ? strcmp( $a->text, $b->text ) : 0; 2597 if ( 0 !== $by_text ) { 2598 return $by_text; 2599 } 2600 2601 /* 2602 * This code should be unreachable, because it implies the two replacements 2603 * start at the same location and contain the same text. 2604 */ 2605 return $a->length - $b->length; 2606 } 2607 2608 /** 2609 * Return the enqueued value for a given attribute, if one exists. 2610 * 2611 * Enqueued updates can take different data types: 2612 * - If an update is enqueued and is boolean, the return will be `true` 2613 * - If an update is otherwise enqueued, the return will be the string value of that update. 2614 * - If an attribute is enqueued to be removed, the return will be `null` to indicate that. 2615 * - If no updates are enqueued, the return will be `false` to differentiate from "removed." 2616 * 2617 * @since 6.2.0 2618 * 2619 * @param string $comparable_name The attribute name in its comparable form. 2620 * @return string|boolean|null Value of enqueued update if present, otherwise false. 2621 */ 2622 private function get_enqueued_attribute_value( string $comparable_name ) { 2623 if ( self::STATE_MATCHED_TAG !== $this->parser_state ) { 2624 return false; 2625 } 2626 2627 if ( ! isset( $this->lexical_updates[ $comparable_name ] ) ) { 2628 return false; 2629 } 2630 2631 $enqueued_text = $this->lexical_updates[ $comparable_name ]->text; 2632 2633 // Removed attributes erase the entire span. 2634 if ( '' === $enqueued_text ) { 2635 return null; 2636 } 2637 2638 /* 2639 * Boolean attribute updates are just the attribute name without a corresponding value. 2640 * 2641 * This value might differ from the given comparable name in that there could be leading 2642 * or trailing whitespace, and that the casing follows the name given in `set_attribute`. 2643 * 2644 * Example: 2645 * 2646 * $p->set_attribute( 'data-TEST-id', 'update' ); 2647 * 'update' === $p->get_enqueued_attribute_value( 'data-test-id' ); 2648 * 2649 * Detect this difference based on the absence of the `=`, which _must_ exist in any 2650 * attribute containing a value, e.g. `<input type="text" enabled />`. 2651 * ¹ ² 2652 * 1. Attribute with a string value. 2653 * 2. Boolean attribute whose value is `true`. 2654 */ 2655 $equals_at = strpos( $enqueued_text, '=' ); 2656 if ( false === $equals_at ) { 2657 return true; 2658 } 2659 2660 /* 2661 * Finally, a normal update's value will appear after the `=` and 2662 * be double-quoted, as performed incidentally by `set_attribute`. 2663 * 2664 * e.g. `type="text"` 2665 * ¹² ³ 2666 * 1. Equals is here. 2667 * 2. Double-quoting starts one after the equals sign. 2668 * 3. Double-quoting ends at the last character in the update. 2669 */ 2670 $enqueued_value = substr( $enqueued_text, $equals_at + 2, -1 ); 2671 return WP_HTML_Decoder::decode_attribute( $enqueued_value ); 2672 } 2673 2674 /** 2675 * Returns the value of a requested attribute from a matched tag opener if that attribute exists. 2676 * 2677 * Example: 2678 * 2679 * $p = new WP_HTML_Tag_Processor( '<div enabled class="test" data-test-id="14">Test</div>' ); 2680 * $p->next_tag( array( 'class_name' => 'test' ) ) === true; 2681 * $p->get_attribute( 'data-test-id' ) === '14'; 2682 * $p->get_attribute( 'enabled' ) === true; 2683 * $p->get_attribute( 'aria-label' ) === null; 2684 * 2685 * $p->next_tag() === false; 2686 * $p->get_attribute( 'class' ) === null; 2687 * 2688 * @since 6.2.0 2689 * 2690 * @param string $name Name of attribute whose value is requested. 2691 * @return string|true|null Value of attribute or `null` if not available. Boolean attributes return `true`. 2692 */ 2693 public function get_attribute( $name ) { 2694 if ( self::STATE_MATCHED_TAG !== $this->parser_state ) { 2695 return null; 2696 } 2697 2698 $comparable = strtolower( $name ); 2699 2700 /* 2701 * For every attribute other than `class` it's possible to perform a quick check if 2702 * there's an enqueued lexical update whose value takes priority over what's found in 2703 * the input document. 2704 * 2705 * The `class` attribute is special though because of the exposed helpers `add_class` 2706 * and `remove_class`. These form a builder for the `class` attribute, so an additional 2707 * check for enqueued class changes is required in addition to the check for any enqueued 2708 * attribute values. If any exist, those enqueued class changes must first be flushed out 2709 * into an attribute value update. 2710 */ 2711 if ( 'class' === $name ) { 2712 $this->class_name_updates_to_attributes_updates(); 2713 } 2714 2715 // Return any enqueued attribute value updates if they exist. 2716 $enqueued_value = $this->get_enqueued_attribute_value( $comparable ); 2717 if ( false !== $enqueued_value ) { 2718 return $enqueued_value; 2719 } 2720 2721 if ( ! isset( $this->attributes[ $comparable ] ) ) { 2722 return null; 2723 } 2724 2725 $attribute = $this->attributes[ $comparable ]; 2726 2727 /* 2728 * This flag distinguishes an attribute with no value 2729 * from an attribute with an empty string value. For 2730 * unquoted attributes this could look very similar. 2731 * It refers to whether an `=` follows the name. 2732 * 2733 * e.g. <div boolean-attribute empty-attribute=></div> 2734 * ¹ ² 2735 * 1. Attribute `boolean-attribute` is `true`. 2736 * 2. Attribute `empty-attribute` is `""`. 2737 */ 2738 if ( true === $attribute->is_true ) { 2739 return true; 2740 } 2741 2742 $raw_value = substr( $this->html, $attribute->value_starts_at, $attribute->value_length ); 2743 2744 return WP_HTML_Decoder::decode_attribute( $raw_value ); 2745 } 2746 2747 /** 2748 * Gets lowercase names of all attributes matching a given prefix in the current tag. 2749 * 2750 * Note that matching is case-insensitive. This is in accordance with the spec: 2751 * 2752 * > There must never be two or more attributes on 2753 * > the same start tag whose names are an ASCII 2754 * > case-insensitive match for each other. 2755 * - HTML 5 spec 2756 * 2757 * Example: 2758 * 2759 * $p = new WP_HTML_Tag_Processor( '<div data-ENABLED class="test" DATA-test-id="14">Test</div>' ); 2760 * $p->next_tag( array( 'class_name' => 'test' ) ) === true; 2761 * $p->get_attribute_names_with_prefix( 'data-' ) === array( 'data-enabled', 'data-test-id' ); 2762 * 2763 * $p->next_tag() === false; 2764 * $p->get_attribute_names_with_prefix( 'data-' ) === null; 2765 * 2766 * @since 6.2.0 2767 * 2768 * @see https://html.spec.whatwg.org/multipage/syntax.html#attributes-2:ascii-case-insensitive 2769 * 2770 * @param string $prefix Prefix of requested attribute names. 2771 * @return array|null List of attribute names, or `null` when no tag opener is matched. 2772 */ 2773 public function get_attribute_names_with_prefix( $prefix ): ?array { 2774 if ( 2775 self::STATE_MATCHED_TAG !== $this->parser_state || 2776 $this->is_closing_tag 2777 ) { 2778 return null; 2779 } 2780 2781 $comparable = strtolower( $prefix ); 2782 2783 $matches = array(); 2784 foreach ( array_keys( $this->attributes ) as $attr_name ) { 2785 if ( str_starts_with( $attr_name, $comparable ) ) { 2786 $matches[] = $attr_name; 2787 } 2788 } 2789 return $matches; 2790 } 2791 2792 /** 2793 * Returns the namespace of the matched token. 2794 * 2795 * @since 6.7.0 2796 * 2797 * @return string One of 'html', 'math', or 'svg'. 2798 */ 2799 public function get_namespace(): string { 2800 return $this->parsing_namespace; 2801 } 2802 2803 /** 2804 * Returns the uppercase name of the matched tag. 2805 * 2806 * Example: 2807 * 2808 * $p = new WP_HTML_Tag_Processor( '<div class="test">Test</div>' ); 2809 * $p->next_tag() === true; 2810 * $p->get_tag() === 'DIV'; 2811 * 2812 * $p->next_tag() === false; 2813 * $p->get_tag() === null; 2814 * 2815 * @since 6.2.0 2816 * 2817 * @return string|null Name of currently matched tag in input HTML, or `null` if none found. 2818 */ 2819 public function get_tag(): ?string { 2820 if ( null === $this->tag_name_starts_at ) { 2821 return null; 2822 } 2823 2824 $tag_name = substr( $this->html, $this->tag_name_starts_at, $this->tag_name_length ); 2825 2826 if ( self::STATE_MATCHED_TAG === $this->parser_state ) { 2827 return strtoupper( $tag_name ); 2828 } 2829 2830 if ( 2831 self::STATE_COMMENT === $this->parser_state && 2832 self::COMMENT_AS_PI_NODE_LOOKALIKE === $this->get_comment_type() 2833 ) { 2834 return $tag_name; 2835 } 2836 2837 return null; 2838 } 2839 2840 /** 2841 * Returns the adjusted tag name for a given token, taking into 2842 * account the current parsing context, whether HTML, SVG, or MathML. 2843 * 2844 * @since 6.7.0 2845 * 2846 * @return string|null Name of current tag name. 2847 */ 2848 public function get_qualified_tag_name(): ?string { 2849 $tag_name = $this->get_tag(); 2850 if ( null === $tag_name ) { 2851 return null; 2852 } 2853 2854 if ( 'html' === $this->get_namespace() ) { 2855 return $tag_name; 2856 } 2857 2858 $lower_tag_name = strtolower( $tag_name ); 2859 if ( 'math' === $this->get_namespace() ) { 2860 return $lower_tag_name; 2861 } 2862 2863 if ( 'svg' === $this->get_namespace() ) { 2864 switch ( $lower_tag_name ) { 2865 case 'altglyph': 2866 return 'altGlyph'; 2867 2868 case 'altglyphdef': 2869 return 'altGlyphDef'; 2870 2871 case 'altglyphitem': 2872 return 'altGlyphItem'; 2873 2874 case 'animatecolor': 2875 return 'animateColor'; 2876 2877 case 'animatemotion': 2878 return 'animateMotion'; 2879 2880 case 'animatetransform': 2881 return 'animateTransform'; 2882 2883 case 'clippath': 2884 return 'clipPath'; 2885 2886 case 'feblend': 2887 return 'feBlend'; 2888 2889 case 'fecolormatrix': 2890 return 'feColorMatrix'; 2891 2892 case 'fecomponenttransfer': 2893 return 'feComponentTransfer'; 2894 2895 case 'fecomposite': 2896 return 'feComposite'; 2897 2898 case 'feconvolvematrix': 2899 return 'feConvolveMatrix'; 2900 2901 case 'fediffuselighting': 2902 return 'feDiffuseLighting'; 2903 2904 case 'fedisplacementmap': 2905 return 'feDisplacementMap'; 2906 2907 case 'fedistantlight': 2908 return 'feDistantLight'; 2909 2910 case 'fedropshadow': 2911 return 'feDropShadow'; 2912 2913 case 'feflood': 2914 return 'feFlood'; 2915 2916 case 'fefunca': 2917 return 'feFuncA'; 2918 2919 case 'fefuncb': 2920 return 'feFuncB'; 2921 2922 case 'fefuncg': 2923 return 'feFuncG'; 2924 2925 case 'fefuncr': 2926 return 'feFuncR'; 2927 2928 case 'fegaussianblur': 2929 return 'feGaussianBlur'; 2930 2931 case 'feimage': 2932 return 'feImage'; 2933 2934 case 'femerge': 2935 return 'feMerge'; 2936 2937 case 'femergenode': 2938 return 'feMergeNode'; 2939 2940 case 'femorphology': 2941 return 'feMorphology'; 2942 2943 case 'feoffset': 2944 return 'feOffset'; 2945 2946 case 'fepointlight': 2947 return 'fePointLight'; 2948 2949 case 'fespecularlighting': 2950 return 'feSpecularLighting'; 2951 2952 case 'fespotlight': 2953 return 'feSpotLight'; 2954 2955 case 'fetile': 2956 return 'feTile'; 2957 2958 case 'feturbulence': 2959 return 'feTurbulence'; 2960 2961 case 'foreignobject': 2962 return 'foreignObject'; 2963 2964 case 'glyphref': 2965 return 'glyphRef'; 2966 2967 case 'lineargradient': 2968 return 'linearGradient'; 2969 2970 case 'radialgradient': 2971 return 'radialGradient'; 2972 2973 case 'textpath': 2974 return 'textPath'; 2975 2976 default: 2977 return $lower_tag_name; 2978 } 2979 } 2980 2981 // This unnecessary return prevents tools from inaccurately reporting type errors. 2982 return $tag_name; 2983 } 2984 2985 /** 2986 * Returns the adjusted attribute name for a given attribute, taking into 2987 * account the current parsing context, whether HTML, SVG, or MathML. 2988 * 2989 * @since 6.7.0 2990 * 2991 * @param string $attribute_name Which attribute to adjust. 2992 * 2993 * @return string|null 2994 */ 2995 public function get_qualified_attribute_name( $attribute_name ): ?string { 2996 if ( self::STATE_MATCHED_TAG !== $this->parser_state ) { 2997 return null; 2998 } 2999 3000 $namespace = $this->get_namespace(); 3001 $lower_name = strtolower( $attribute_name ); 3002 3003 if ( 'math' === $namespace && 'definitionurl' === $lower_name ) { 3004 return 'definitionURL'; 3005 } 3006 3007 if ( 'svg' === $this->get_namespace() ) { 3008 switch ( $lower_name ) { 3009 case 'attributename': 3010 return 'attributeName'; 3011 3012 case 'attributetype': 3013 return 'attributeType'; 3014 3015 case 'basefrequency': 3016 return 'baseFrequency'; 3017 3018 case 'baseprofile': 3019 return 'baseProfile'; 3020 3021 case 'calcmode': 3022 return 'calcMode'; 3023 3024 case 'clippathunits': 3025 return 'clipPathUnits'; 3026 3027 case 'diffuseconstant': 3028 return 'diffuseConstant'; 3029 3030 case 'edgemode': 3031 return 'edgeMode'; 3032 3033 case 'filterunits': 3034 return 'filterUnits'; 3035 3036 case 'glyphref': 3037 return 'glyphRef'; 3038 3039 case 'gradienttransform': 3040 return 'gradientTransform'; 3041 3042 case 'gradientunits': 3043 return 'gradientUnits'; 3044 3045 case 'kernelmatrix': 3046 return 'kernelMatrix'; 3047 3048 case 'kernelunitlength': 3049 return 'kernelUnitLength'; 3050 3051 case 'keypoints': 3052 return 'keyPoints'; 3053 3054 case 'keysplines': 3055 return 'keySplines'; 3056 3057 case 'keytimes': 3058 return 'keyTimes'; 3059 3060 case 'lengthadjust': 3061 return 'lengthAdjust'; 3062 3063 case 'limitingconeangle': 3064 return 'limitingConeAngle'; 3065 3066 case 'markerheight': 3067 return 'markerHeight'; 3068 3069 case 'markerunits': 3070 return 'markerUnits'; 3071 3072 case 'markerwidth': 3073 return 'markerWidth'; 3074 3075 case 'maskcontentunits': 3076 return 'maskContentUnits'; 3077 3078 case 'maskunits': 3079 return 'maskUnits'; 3080 3081 case 'numoctaves': 3082 return 'numOctaves'; 3083 3084 case 'pathlength': 3085 return 'pathLength'; 3086 3087 case 'patterncontentunits': 3088 return 'patternContentUnits'; 3089 3090 case 'patterntransform': 3091 return 'patternTransform'; 3092 3093 case 'patternunits': 3094 return 'patternUnits'; 3095 3096 case 'pointsatx': 3097 return 'pointsAtX'; 3098 3099 case 'pointsaty': 3100 return 'pointsAtY'; 3101 3102 case 'pointsatz': 3103 return 'pointsAtZ'; 3104 3105 case 'preservealpha': 3106 return 'preserveAlpha'; 3107 3108 case 'preserveaspectratio': 3109 return 'preserveAspectRatio'; 3110 3111 case 'primitiveunits': 3112 return 'primitiveUnits'; 3113 3114 case 'refx': 3115 return 'refX'; 3116 3117 case 'refy': 3118 return 'refY'; 3119 3120 case 'repeatcount': 3121 return 'repeatCount'; 3122 3123 case 'repeatdur': 3124 return 'repeatDur'; 3125 3126 case 'requiredextensions': 3127 return 'requiredExtensions'; 3128 3129 case 'requiredfeatures': 3130 return 'requiredFeatures'; 3131 3132 case 'specularconstant': 3133 return 'specularConstant'; 3134 3135 case 'specularexponent': 3136 return 'specularExponent'; 3137 3138 case 'spreadmethod': 3139 return 'spreadMethod'; 3140 3141 case 'startoffset': 3142 return 'startOffset'; 3143 3144 case 'stddeviation': 3145 return 'stdDeviation'; 3146 3147 case 'stitchtiles': 3148 return 'stitchTiles'; 3149 3150 case 'surfacescale': 3151 return 'surfaceScale'; 3152 3153 case 'systemlanguage': 3154 return 'systemLanguage'; 3155 3156 case 'tablevalues': 3157 return 'tableValues'; 3158 3159 case 'targetx': 3160 return 'targetX'; 3161 3162 case 'targety': 3163 return 'targetY'; 3164 3165 case 'textlength': 3166 return 'textLength'; 3167 3168 case 'viewbox': 3169 return 'viewBox'; 3170 3171 case 'viewtarget': 3172 return 'viewTarget'; 3173 3174 case 'xchannelselector': 3175 return 'xChannelSelector'; 3176 3177 case 'ychannelselector': 3178 return 'yChannelSelector'; 3179 3180 case 'zoomandpan': 3181 return 'zoomAndPan'; 3182 } 3183 } 3184 3185 if ( 'html' !== $namespace ) { 3186 switch ( $lower_name ) { 3187 case 'xlink:actuate': 3188 return 'xlink actuate'; 3189 3190 case 'xlink:arcrole': 3191 return 'xlink arcrole'; 3192 3193 case 'xlink:href': 3194 return 'xlink href'; 3195 3196 case 'xlink:role': 3197 return 'xlink role'; 3198 3199 case 'xlink:show': 3200 return 'xlink show'; 3201 3202 case 'xlink:title': 3203 return 'xlink title'; 3204 3205 case 'xlink:type': 3206 return 'xlink type'; 3207 3208 case 'xml:lang': 3209 return 'xml lang'; 3210 3211 case 'xml:space': 3212 return 'xml space'; 3213 3214 case 'xmlns': 3215 return 'xmlns'; 3216 3217 case 'xmlns:xlink': 3218 return 'xmlns xlink'; 3219 } 3220 } 3221 3222 return $attribute_name; 3223 } 3224 3225 /** 3226 * Indicates if the currently matched tag contains the self-closing flag. 3227 * 3228 * No HTML elements ought to have the self-closing flag and for those, the self-closing 3229 * flag will be ignored. For void elements this is benign because they "self close" 3230 * automatically. For non-void HTML elements though problems will appear if someone 3231 * intends to use a self-closing element in place of that element with an empty body. 3232 * For HTML foreign elements and custom elements the self-closing flag determines if 3233 * they self-close or not. 3234 * 3235 * This function does not determine if a tag is self-closing, 3236 * but only if the self-closing flag is present in the syntax. 3237 * 3238 * @since 6.3.0 3239 * 3240 * @return bool Whether the currently matched tag contains the self-closing flag. 3241 */ 3242 public function has_self_closing_flag(): bool { 3243 if ( self::STATE_MATCHED_TAG !== $this->parser_state ) { 3244 return false; 3245 } 3246 3247 /* 3248 * The self-closing flag is the solidus at the _end_ of the tag, not the beginning. 3249 * 3250 * Example: 3251 * 3252 * <figure /> 3253 * ^ this appears one character before the end of the closing ">". 3254 */ 3255 return '/' === $this->html[ $this->token_starts_at + $this->token_length - 2 ]; 3256 } 3257 3258 /** 3259 * Indicates if the current tag token is a tag closer. 3260 * 3261 * Example: 3262 * 3263 * $p = new WP_HTML_Tag_Processor( '<div></div>' ); 3264 * $p->next_tag( array( 'tag_name' => 'div', 'tag_closers' => 'visit' ) ); 3265 * $p->is_tag_closer() === false; 3266 * 3267 * $p->next_tag( array( 'tag_name' => 'div', 'tag_closers' => 'visit' ) ); 3268 * $p->is_tag_closer() === true; 3269 * 3270 * @since 6.2.0 3271 * @since 6.7.0 Reports all BR tags as opening tags. 3272 * 3273 * @return bool Whether the current tag is a tag closer. 3274 */ 3275 public function is_tag_closer(): bool { 3276 return ( 3277 self::STATE_MATCHED_TAG === $this->parser_state && 3278 $this->is_closing_tag && 3279 3280 /* 3281 * The BR tag can only exist as an opening tag. If something like `</br>` 3282 * appears then the HTML parser will treat it as an opening tag with no 3283 * attributes. The BR tag is unique in this way. 3284 * 3285 * @see https://html.spec.whatwg.org/#parsing-main-inbody 3286 */ 3287 'BR' !== $this->get_tag() 3288 ); 3289 } 3290 3291 /** 3292 * Indicates the kind of matched token, if any. 3293 * 3294 * This differs from `get_token_name()` in that it always 3295 * returns a static string indicating the type, whereas 3296 * `get_token_name()` may return values derived from the 3297 * token itself, such as a tag name or processing 3298 * instruction tag. 3299 * 3300 * Possible values: 3301 * - `#tag` when matched on a tag. 3302 * - `#text` when matched on a text node. 3303 * - `#cdata-section` when matched on a CDATA node. 3304 * - `#comment` when matched on a comment. 3305 * - `#doctype` when matched on a DOCTYPE declaration. 3306 * - `#presumptuous-tag` when matched on an empty tag closer. 3307 * - `#funky-comment` when matched on a funky comment. 3308 * 3309 * @since 6.5.0 3310 * 3311 * @return string|null What kind of token is matched, or null. 3312 */ 3313 public function get_token_type(): ?string { 3314 switch ( $this->parser_state ) { 3315 case self::STATE_MATCHED_TAG: 3316 return '#tag'; 3317 3318 case self::STATE_DOCTYPE: 3319 return '#doctype'; 3320 3321 default: 3322 return $this->get_token_name(); 3323 } 3324 } 3325 3326 /** 3327 * Returns the node name represented by the token. 3328 * 3329 * This matches the DOM API value `nodeName`. Some values 3330 * are static, such as `#text` for a text node, while others 3331 * are dynamically generated from the token itself. 3332 * 3333 * Dynamic names: 3334 * - Uppercase tag name for tag matches. 3335 * - `html` for DOCTYPE declarations. 3336 * 3337 * Note that if the Tag Processor is not matched on a token 3338 * then this function will return `null`, either because it 3339 * hasn't yet found a token or because it reached the end 3340 * of the document without matching a token. 3341 * 3342 * @since 6.5.0 3343 * 3344 * @return string|null Name of the matched token. 3345 */ 3346 public function get_token_name(): ?string { 3347 switch ( $this->parser_state ) { 3348 case self::STATE_MATCHED_TAG: 3349 return $this->get_tag(); 3350 3351 case self::STATE_TEXT_NODE: 3352 return '#text'; 3353 3354 case self::STATE_CDATA_NODE: 3355 return '#cdata-section'; 3356 3357 case self::STATE_COMMENT: 3358 return '#comment'; 3359 3360 case self::STATE_DOCTYPE: 3361 return 'html'; 3362 3363 case self::STATE_PRESUMPTUOUS_TAG: 3364 return '#presumptuous-tag'; 3365 3366 case self::STATE_FUNKY_COMMENT: 3367 return '#funky-comment'; 3368 } 3369 3370 return null; 3371 } 3372 3373 /** 3374 * Indicates what kind of comment produced the comment node. 3375 * 3376 * Because there are different kinds of HTML syntax which produce 3377 * comments, the Tag Processor tracks and exposes this as a type 3378 * for the comment. Nominally only regular HTML comments exist as 3379 * they are commonly known, but a number of unrelated syntax errors 3380 * also produce comments. 3381 * 3382 * @see self::COMMENT_AS_ABRUPTLY_CLOSED_COMMENT 3383 * @see self::COMMENT_AS_CDATA_LOOKALIKE 3384 * @see self::COMMENT_AS_INVALID_HTML 3385 * @see self::COMMENT_AS_HTML_COMMENT 3386 * @see self::COMMENT_AS_PI_NODE_LOOKALIKE 3387 * 3388 * @since 6.5.0 3389 * 3390 * @return string|null 3391 */ 3392 public function get_comment_type(): ?string { 3393 if ( self::STATE_COMMENT !== $this->parser_state ) { 3394 return null; 3395 } 3396 3397 return $this->comment_type; 3398 } 3399 3400 /** 3401 * Returns the text of a matched comment or null if not on a comment type node. 3402 * 3403 * This method returns the entire text content of a comment node as it 3404 * would appear in the browser. 3405 * 3406 * This differs from {@see ::get_modifiable_text()} in that certain comment 3407 * types in the HTML API cannot allow their entire comment text content to 3408 * be modified. Namely, "bogus comments" of the form `<?not allowed in html>` 3409 * will create a comment whose text content starts with `?`. Note that if 3410 * that character were modified, it would be possible to change the node 3411 * type. 3412 * 3413 * @since 6.7.0 3414 * 3415 * @return string|null The comment text as it would appear in the browser or null 3416 * if not on a comment type node. 3417 */ 3418 public function get_full_comment_text(): ?string { 3419 if ( self::STATE_FUNKY_COMMENT === $this->parser_state ) { 3420 return $this->get_modifiable_text(); 3421 } 3422 3423 if ( self::STATE_COMMENT !== $this->parser_state ) { 3424 return null; 3425 } 3426 3427 switch ( $this->get_comment_type() ) { 3428 case self::COMMENT_AS_HTML_COMMENT: 3429 case self::COMMENT_AS_ABRUPTLY_CLOSED_COMMENT: 3430 return $this->get_modifiable_text(); 3431 3432 case self::COMMENT_AS_CDATA_LOOKALIKE: 3433 return "[CDATA[{$this->get_modifiable_text()}]]"; 3434 3435 case self::COMMENT_AS_PI_NODE_LOOKALIKE: 3436 return "?{$this->get_tag()}{$this->get_modifiable_text()}?"; 3437 3438 /* 3439 * This represents "bogus comments state" from HTML tokenization. 3440 * This can be entered by `<?` or `<!`, where `?` is included in 3441 * the comment text but `!` is not. 3442 */ 3443 case self::COMMENT_AS_INVALID_HTML: 3444 $preceding_character = $this->html[ $this->text_starts_at - 1 ]; 3445 $comment_start = '?' === $preceding_character ? '?' : ''; 3446 return "{$comment_start}{$this->get_modifiable_text()}"; 3447 } 3448 3449 return null; 3450 } 3451 3452 /** 3453 * Subdivides a matched text node, splitting NULL byte sequences and decoded whitespace as 3454 * distinct nodes prefixes. 3455 * 3456 * Note that once anything that's neither a NULL byte nor decoded whitespace is 3457 * encountered, then the remainder of the text node is left intact as generic text. 3458 * 3459 * - The HTML Processor uses this to apply distinct rules for different kinds of text. 3460 * - Inter-element whitespace can be detected and skipped with this method. 3461 * 3462 * Text nodes aren't eagerly subdivided because there's no need to split them unless 3463 * decisions are being made on NULL byte sequences or whitespace-only text. 3464 * 3465 * Example: 3466 * 3467 * $processor = new WP_HTML_Tag_Processor( "\x00Apples & Oranges" ); 3468 * true === $processor->next_token(); // Text is "Apples & Oranges". 3469 * true === $processor->subdivide_text_appropriately(); // Text is "". 3470 * true === $processor->next_token(); // Text is "Apples & Oranges". 3471 * false === $processor->subdivide_text_appropriately(); 3472 * 3473 * $processor = new WP_HTML_Tag_Processor( " \r\n\tMore" ); 3474 * true === $processor->next_token(); // Text is " ␉More". 3475 * true === $processor->subdivide_text_appropriately(); // Text is " ␉". 3476 * true === $processor->next_token(); // Text is "More". 3477 * false === $processor->subdivide_text_appropriately(); 3478 * 3479 * @since 6.7.0 3480 * 3481 * @return bool Whether the text node was subdivided. 3482 */ 3483 public function subdivide_text_appropriately(): bool { 3484 if ( self::STATE_TEXT_NODE !== $this->parser_state ) { 3485 return false; 3486 } 3487 3488 $this->text_node_classification = self::TEXT_IS_GENERIC; 3489 3490 /* 3491 * NULL bytes are treated categorically different than numeric character 3492 * references whose number is zero. `�` is not the same as `"\x00"`. 3493 */ 3494 $leading_nulls = strspn( $this->html, "\x00", $this->text_starts_at, $this->text_length ); 3495 if ( $leading_nulls > 0 ) { 3496 $this->token_length = $leading_nulls; 3497 $this->text_length = $leading_nulls; 3498 $this->bytes_already_parsed = $this->token_starts_at + $leading_nulls; 3499 $this->text_node_classification = self::TEXT_IS_NULL_SEQUENCE; 3500 return true; 3501 } 3502 3503 /* 3504 * Start a decoding loop to determine the point at which the 3505 * text subdivides. This entails raw whitespace bytes and any 3506 * character reference that decodes to the same. 3507 */ 3508 $at = $this->text_starts_at; 3509 $end = $this->text_starts_at + $this->text_length; 3510 while ( $at < $end ) { 3511 $skipped = strspn( $this->html, " \t\f\r\n", $at, $end - $at ); 3512 $at += $skipped; 3513 3514 if ( $at < $end && '&' === $this->html[ $at ] ) { 3515 $matched_byte_length = null; 3516 $replacement = WP_HTML_Decoder::read_character_reference( 'data', $this->html, $at, $matched_byte_length ); 3517 if ( isset( $replacement ) && 1 === strspn( $replacement, " \t\f\r\n" ) ) { 3518 $at += $matched_byte_length; 3519 continue; 3520 } 3521 } 3522 3523 break; 3524 } 3525 3526 if ( $at > $this->text_starts_at ) { 3527 $new_length = $at - $this->text_starts_at; 3528 $this->text_length = $new_length; 3529 $this->token_length = $new_length; 3530 $this->bytes_already_parsed = $at; 3531 $this->text_node_classification = self::TEXT_IS_WHITESPACE; 3532 return true; 3533 } 3534 3535 return false; 3536 } 3537 3538 /** 3539 * Returns the modifiable text for a matched token, or an empty string. 3540 * 3541 * Modifiable text is text content that may be read and changed without 3542 * changing the HTML structure of the document around it. This includes 3543 * the contents of `#text` nodes in the HTML as well as the inner 3544 * contents of HTML comments, Processing Instructions, and others, even 3545 * though these nodes aren't part of a parsed DOM tree. They also contain 3546 * the contents of SCRIPT and STYLE tags, of TEXTAREA tags, and of any 3547 * other section in an HTML document which cannot contain HTML markup (DATA). 3548 * 3549 * If a token has no modifiable text then an empty string is returned to 3550 * avoid needless crashing or type errors. An empty string does not mean 3551 * that a token has modifiable text, and a token with modifiable text may 3552 * have an empty string (e.g. a comment with no contents). 3553 * 3554 * Limitations: 3555 * 3556 * - This function will not strip the leading newline appropriately 3557 * after seeking into a LISTING or PRE element. To ensure that the 3558 * newline is treated properly, seek to the LISTING or PRE opening 3559 * tag instead of to the first text node inside the element. 3560 * 3561 * @since 6.5.0 3562 * @since 6.7.0 Replaces NULL bytes (U+0000) and newlines appropriately. 3563 * 3564 * @return string 3565 */ 3566 public function get_modifiable_text(): string { 3567 $has_enqueued_update = isset( $this->lexical_updates['modifiable text'] ); 3568 3569 if ( ! $has_enqueued_update && ( null === $this->text_starts_at || 0 === $this->text_length ) ) { 3570 return ''; 3571 } 3572 3573 $text = $has_enqueued_update 3574 ? $this->lexical_updates['modifiable text']->text 3575 : substr( $this->html, $this->text_starts_at, $this->text_length ); 3576 3577 /* 3578 * Pre-processing the input stream would normally happen before 3579 * any parsing is done, but deferring it means it's possible to 3580 * skip in most cases. When getting the modifiable text, however 3581 * it's important to apply the pre-processing steps, which is 3582 * normalizing newlines. 3583 * 3584 * @see https://html.spec.whatwg.org/#preprocessing-the-input-stream 3585 * @see https://infra.spec.whatwg.org/#normalize-newlines 3586 */ 3587 $text = str_replace( "\r\n", "\n", $text ); 3588 $text = str_replace( "\r", "\n", $text ); 3589 3590 // Comment data is not decoded. 3591 if ( 3592 self::STATE_CDATA_NODE === $this->parser_state || 3593 self::STATE_COMMENT === $this->parser_state || 3594 self::STATE_DOCTYPE === $this->parser_state || 3595 self::STATE_FUNKY_COMMENT === $this->parser_state 3596 ) { 3597 return str_replace( "\x00", "\u{FFFD}", $text ); 3598 } 3599 3600 $tag_name = $this->get_token_name(); 3601 if ( 3602 // Script data is not decoded. 3603 'SCRIPT' === $tag_name || 3604 3605 // RAWTEXT data is not decoded. 3606 'IFRAME' === $tag_name || 3607 'NOEMBED' === $tag_name || 3608 'NOFRAMES' === $tag_name || 3609 'STYLE' === $tag_name || 3610 'XMP' === $tag_name 3611 ) { 3612 return str_replace( "\x00", "\u{FFFD}", $text ); 3613 } 3614 3615 $decoded = WP_HTML_Decoder::decode_text_node( $text ); 3616 3617 /* 3618 * Skip the first line feed after LISTING, PRE, and TEXTAREA opening tags. 3619 * 3620 * Note that this first newline may come in the form of a character 3621 * reference, such as `
`, and so it's important to perform 3622 * this transformation only after decoding the raw text content. 3623 */ 3624 if ( 3625 ( "\n" === ( $decoded[0] ?? '' ) ) && 3626 ( ( $this->skip_newline_at === $this->token_starts_at && '#text' === $tag_name ) || 'TEXTAREA' === $tag_name ) 3627 ) { 3628 $decoded = substr( $decoded, 1 ); 3629 } 3630 3631 /* 3632 * Only in normative text nodes does the NULL byte (U+0000) get removed. 3633 * In all other contexts it's replaced by the replacement character (U+FFFD) 3634 * for security reasons (to avoid joining together strings that were safe 3635 * when separated, but not when joined). 3636 * 3637 * @todo Inside HTML integration points and MathML integration points, the 3638 * text is processed according to the insertion mode, not according 3639 * to the foreign content rules. This should strip the NULL bytes. 3640 */ 3641 return ( '#text' === $tag_name && 'html' === $this->get_namespace() ) 3642 ? str_replace( "\x00", '', $decoded ) 3643 : str_replace( "\x00", "\u{FFFD}", $decoded ); 3644 } 3645 3646 /** 3647 * Sets the modifiable text for the matched token, if matched. 3648 * 3649 * Modifiable text is text content that may be read and changed without 3650 * changing the HTML structure of the document around it. This includes 3651 * the contents of `#text` nodes in the HTML as well as the inner 3652 * contents of HTML comments, Processing Instructions, and others, even 3653 * though these nodes aren't part of a parsed DOM tree. They also contain 3654 * the contents of SCRIPT and STYLE tags, of TEXTAREA tags, and of any 3655 * other section in an HTML document which cannot contain HTML markup (DATA). 3656 * 3657 * Not all modifiable text may be set by this method, and not all content 3658 * may be set as modifiable text. In the case that this fails it will return 3659 * `false` indicating as much. For instance, it will not allow inserting the 3660 * string `</script` into a SCRIPT element, because the rules for escaping 3661 * that safely are complicated. Similarly, it will not allow setting content 3662 * into a comment which would prematurely terminate the comment. 3663 * 3664 * Example: 3665 * 3666 * // Add a preface to all STYLE contents. 3667 * while ( $processor->next_tag( 'STYLE' ) ) { 3668 * $style = $processor->get_modifiable_text(); 3669 * $processor->set_modifiable_text( "// Made with love on the World Wide Web\n{$style}" ); 3670 * } 3671 * 3672 * // Replace smiley text with Emoji smilies. 3673 * while ( $processor->next_token() ) { 3674 * if ( '#text' !== $processor->get_token_name() ) { 3675 * continue; 3676 * } 3677 * 3678 * $chunk = $processor->get_modifiable_text(); 3679 * if ( ! str_contains( $chunk, ':)' ) ) { 3680 * continue; 3681 * } 3682 * 3683 * $processor->set_modifiable_text( str_replace( ':)', '🙂', $chunk ) ); 3684 * } 3685 * 3686 * @since 6.7.0 3687 * 3688 * @param string $plaintext_content New text content to represent in the matched token. 3689 * 3690 * @return bool Whether the text was able to update. 3691 */ 3692 public function set_modifiable_text( string $plaintext_content ): bool { 3693 if ( self::STATE_TEXT_NODE === $this->parser_state ) { 3694 $this->lexical_updates['modifiable text'] = new WP_HTML_Text_Replacement( 3695 $this->text_starts_at, 3696 $this->text_length, 3697 htmlspecialchars( $plaintext_content, ENT_QUOTES | ENT_HTML5 ) 3698 ); 3699 3700 return true; 3701 } 3702 3703 // Comment data is not encoded. 3704 if ( 3705 self::STATE_COMMENT === $this->parser_state && 3706 self::COMMENT_AS_HTML_COMMENT === $this->comment_type 3707 ) { 3708 // Check if the text could close the comment. 3709 if ( 1 === preg_match( '/--!?>/', $plaintext_content ) ) { 3710 return false; 3711 } 3712 3713 $this->lexical_updates['modifiable text'] = new WP_HTML_Text_Replacement( 3714 $this->text_starts_at, 3715 $this->text_length, 3716 $plaintext_content 3717 ); 3718 3719 return true; 3720 } 3721 3722 if ( self::STATE_MATCHED_TAG !== $this->parser_state ) { 3723 return false; 3724 } 3725 3726 switch ( $this->get_tag() ) { 3727 case 'SCRIPT': 3728 /* 3729 * This is over-protective, but ensures the update doesn't break 3730 * out of the SCRIPT element. A more thorough check would need to 3731 * ensure that the script closing tag doesn't exist, and isn't 3732 * also "hidden" inside the script double-escaped state. 3733 * 3734 * It may seem like replacing `</script` with `<\/script` would 3735 * properly escape these things, but this could mask regex patterns 3736 * that previously worked. Resolve this by not sending `</script` 3737 */ 3738 if ( false !== stripos( $plaintext_content, '</script' ) ) { 3739 return false; 3740 } 3741 3742 $this->lexical_updates['modifiable text'] = new WP_HTML_Text_Replacement( 3743 $this->text_starts_at, 3744 $this->text_length, 3745 $plaintext_content 3746 ); 3747 3748 return true; 3749 3750 case 'STYLE': 3751 $plaintext_content = preg_replace_callback( 3752 '~</(?P<TAG_NAME>style)~i', 3753 static function ( $tag_match ) { 3754 return "\\3c\\2f{$tag_match['TAG_NAME']}"; 3755 }, 3756 $plaintext_content 3757 ); 3758 3759 $this->lexical_updates['modifiable text'] = new WP_HTML_Text_Replacement( 3760 $this->text_starts_at, 3761 $this->text_length, 3762 $plaintext_content 3763 ); 3764 3765 return true; 3766 3767 case 'TEXTAREA': 3768 case 'TITLE': 3769 $plaintext_content = preg_replace_callback( 3770 "~</(?P<TAG_NAME>{$this->get_tag()})~i", 3771 static function ( $tag_match ) { 3772 return "</{$tag_match['TAG_NAME']}"; 3773 }, 3774 $plaintext_content 3775 ); 3776 3777 /* 3778 * These don't _need_ to be escaped, but since they are decoded it's 3779 * safe to leave them escaped and this can prevent other code from 3780 * naively detecting tags within the contents. 3781 * 3782 * @todo It would be useful to prefix a multiline replacement text 3783 * with a newline, but not necessary. This is for aesthetics. 3784 */ 3785 $this->lexical_updates['modifiable text'] = new WP_HTML_Text_Replacement( 3786 $this->text_starts_at, 3787 $this->text_length, 3788 $plaintext_content 3789 ); 3790 3791 return true; 3792 } 3793 3794 return false; 3795 } 3796 3797 /** 3798 * Updates or creates a new attribute on the currently matched tag with the passed value. 3799 * 3800 * For boolean attributes special handling is provided: 3801 * - When `true` is passed as the value, then only the attribute name is added to the tag. 3802 * - When `false` is passed, the attribute gets removed if it existed before. 3803 * 3804 * For string attributes, the value is escaped using the `esc_attr` function. 3805 * 3806 * @since 6.2.0 3807 * @since 6.2.1 Fix: Only create a single update for multiple calls with case-variant attribute names. 3808 * 3809 * @param string $name The attribute name to target. 3810 * @param string|bool $value The new attribute value. 3811 * @return bool Whether an attribute value was set. 3812 */ 3813 public function set_attribute( $name, $value ): bool { 3814 if ( 3815 self::STATE_MATCHED_TAG !== $this->parser_state || 3816 $this->is_closing_tag 3817 ) { 3818 return false; 3819 } 3820 3821 /* 3822 * WordPress rejects more characters than are strictly forbidden 3823 * in HTML5. This is to prevent additional security risks deeper 3824 * in the WordPress and plugin stack. Specifically the 3825 * less-than (<) greater-than (>) and ampersand (&) aren't allowed. 3826 * 3827 * The use of a PCRE match enables looking for specific Unicode 3828 * code points without writing a UTF-8 decoder. Whereas scanning 3829 * for one-byte characters is trivial (with `strcspn`), scanning 3830 * for the longer byte sequences would be more complicated. Given 3831 * that this shouldn't be in the hot path for execution, it's a 3832 * reasonable compromise in efficiency without introducing a 3833 * noticeable impact on the overall system. 3834 * 3835 * @see https://html.spec.whatwg.org/#attributes-2 3836 * 3837 * @todo As the only regex pattern maybe we should take it out? 3838 * Are Unicode patterns available broadly in Core? 3839 */ 3840 if ( preg_match( 3841 '~[' . 3842 // Syntax-like characters. 3843 '"\'>&</ =' . 3844 // Control characters. 3845 '\x{00}-\x{1F}' . 3846 // HTML noncharacters. 3847 '\x{FDD0}-\x{FDEF}' . 3848 '\x{FFFE}\x{FFFF}\x{1FFFE}\x{1FFFF}\x{2FFFE}\x{2FFFF}\x{3FFFE}\x{3FFFF}' . 3849 '\x{4FFFE}\x{4FFFF}\x{5FFFE}\x{5FFFF}\x{6FFFE}\x{6FFFF}\x{7FFFE}\x{7FFFF}' . 3850 '\x{8FFFE}\x{8FFFF}\x{9FFFE}\x{9FFFF}\x{AFFFE}\x{AFFFF}\x{BFFFE}\x{BFFFF}' . 3851 '\x{CFFFE}\x{CFFFF}\x{DFFFE}\x{DFFFF}\x{EFFFE}\x{EFFFF}\x{FFFFE}\x{FFFFF}' . 3852 '\x{10FFFE}\x{10FFFF}' . 3853 ']~Ssu', 3854 $name 3855 ) ) { 3856 _doing_it_wrong( 3857 __METHOD__, 3858 __( 'Invalid attribute name.' ), 3859 '6.2.0' 3860 ); 3861 3862 return false; 3863 } 3864 3865 /* 3866 * > The values "true" and "false" are not allowed on boolean attributes. 3867 * > To represent a false value, the attribute has to be omitted altogether. 3868 * - HTML5 spec, https://html.spec.whatwg.org/#boolean-attributes 3869 */ 3870 if ( false === $value ) { 3871 return $this->remove_attribute( $name ); 3872 } 3873 3874 if ( true === $value ) { 3875 $updated_attribute = $name; 3876 } else { 3877 $comparable_name = strtolower( $name ); 3878 3879 /* 3880 * Escape URL attributes. 3881 * 3882 * @see https://html.spec.whatwg.org/#attributes-3 3883 */ 3884 $escaped_new_value = in_array( $comparable_name, wp_kses_uri_attributes(), true ) ? esc_url( $value ) : esc_attr( $value ); 3885 3886 // If the escaping functions wiped out the update, reject it and indicate it was rejected. 3887 if ( '' === $escaped_new_value && '' !== $value ) { 3888 return false; 3889 } 3890 3891 $updated_attribute = "{$name}=\"{$escaped_new_value}\""; 3892 } 3893 3894 /* 3895 * > There must never be two or more attributes on 3896 * > the same start tag whose names are an ASCII 3897 * > case-insensitive match for each other. 3898 * - HTML 5 spec 3899 * 3900 * @see https://html.spec.whatwg.org/multipage/syntax.html#attributes-2:ascii-case-insensitive 3901 */ 3902 $comparable_name = strtolower( $name ); 3903 3904 if ( isset( $this->attributes[ $comparable_name ] ) ) { 3905 /* 3906 * Update an existing attribute. 3907 * 3908 * Example – set attribute id to "new" in <div id="initial_id" />: 3909 * 3910 * <div id="initial_id"/> 3911 * ^-------------^ 3912 * start end 3913 * replacement: `id="new"` 3914 * 3915 * Result: <div id="new"/> 3916 */ 3917 $existing_attribute = $this->attributes[ $comparable_name ]; 3918 $this->lexical_updates[ $comparable_name ] = new WP_HTML_Text_Replacement( 3919 $existing_attribute->start, 3920 $existing_attribute->length, 3921 $updated_attribute 3922 ); 3923 } else { 3924 /* 3925 * Create a new attribute at the tag's name end. 3926 * 3927 * Example – add attribute id="new" to <div />: 3928 * 3929 * <div/> 3930 * ^ 3931 * start and end 3932 * replacement: ` id="new"` 3933 * 3934 * Result: <div id="new"/> 3935 */ 3936 $this->lexical_updates[ $comparable_name ] = new WP_HTML_Text_Replacement( 3937 $this->tag_name_starts_at + $this->tag_name_length, 3938 0, 3939 ' ' . $updated_attribute 3940 ); 3941 } 3942 3943 /* 3944 * Any calls to update the `class` attribute directly should wipe out any 3945 * enqueued class changes from `add_class` and `remove_class`. 3946 */ 3947 if ( 'class' === $comparable_name && ! empty( $this->classname_updates ) ) { 3948 $this->classname_updates = array(); 3949 } 3950 3951 return true; 3952 } 3953 3954 /** 3955 * Remove an attribute from the currently-matched tag. 3956 * 3957 * @since 6.2.0 3958 * 3959 * @param string $name The attribute name to remove. 3960 * @return bool Whether an attribute was removed. 3961 */ 3962 public function remove_attribute( $name ): bool { 3963 if ( 3964 self::STATE_MATCHED_TAG !== $this->parser_state || 3965 $this->is_closing_tag 3966 ) { 3967 return false; 3968 } 3969 3970 /* 3971 * > There must never be two or more attributes on 3972 * > the same start tag whose names are an ASCII 3973 * > case-insensitive match for each other. 3974 * - HTML 5 spec 3975 * 3976 * @see https://html.spec.whatwg.org/multipage/syntax.html#attributes-2:ascii-case-insensitive 3977 */ 3978 $name = strtolower( $name ); 3979 3980 /* 3981 * Any calls to update the `class` attribute directly should wipe out any 3982 * enqueued class changes from `add_class` and `remove_class`. 3983 */ 3984 if ( 'class' === $name && count( $this->classname_updates ) !== 0 ) { 3985 $this->classname_updates = array(); 3986 } 3987 3988 /* 3989 * If updating an attribute that didn't exist in the input 3990 * document, then remove the enqueued update and move on. 3991 * 3992 * For example, this might occur when calling `remove_attribute()` 3993 * after calling `set_attribute()` for the same attribute 3994 * and when that attribute wasn't originally present. 3995 */ 3996 if ( ! isset( $this->attributes[ $name ] ) ) { 3997 if ( isset( $this->lexical_updates[ $name ] ) ) { 3998 unset( $this->lexical_updates[ $name ] ); 3999 } 4000 return false; 4001 } 4002 4003 /* 4004 * Removes an existing tag attribute. 4005 * 4006 * Example – remove the attribute id from <div id="main"/>: 4007 * <div id="initial_id"/> 4008 * ^-------------^ 4009 * start end 4010 * replacement: `` 4011 * 4012 * Result: <div /> 4013 */ 4014 $this->lexical_updates[ $name ] = new WP_HTML_Text_Replacement( 4015 $this->attributes[ $name ]->start, 4016 $this->attributes[ $name ]->length, 4017 '' 4018 ); 4019 4020 // Removes any duplicated attributes if they were also present. 4021 foreach ( $this->duplicate_attributes[ $name ] ?? array() as $attribute_token ) { 4022 $this->lexical_updates[] = new WP_HTML_Text_Replacement( 4023 $attribute_token->start, 4024 $attribute_token->length, 4025 '' 4026 ); 4027 } 4028 4029 return true; 4030 } 4031 4032 /** 4033 * Adds a new class name to the currently matched tag. 4034 * 4035 * @since 6.2.0 4036 * 4037 * @param string $class_name The class name to add. 4038 * @return bool Whether the class was set to be added. 4039 */ 4040 public function add_class( $class_name ): bool { 4041 if ( 4042 self::STATE_MATCHED_TAG !== $this->parser_state || 4043 $this->is_closing_tag 4044 ) { 4045 return false; 4046 } 4047 4048 if ( self::QUIRKS_MODE !== $this->compat_mode ) { 4049 $this->classname_updates[ $class_name ] = self::ADD_CLASS; 4050 return true; 4051 } 4052 4053 /* 4054 * Because class names are matched ASCII-case-insensitively in quirks mode, 4055 * this needs to see if a case variant of the given class name is already 4056 * enqueued and update that existing entry, if so. This picks the casing of 4057 * the first-provided class name for all lexical variations. 4058 */ 4059 $class_name_length = strlen( $class_name ); 4060 foreach ( $this->classname_updates as $updated_name => $action ) { 4061 if ( 4062 strlen( $updated_name ) === $class_name_length && 4063 0 === substr_compare( $updated_name, $class_name, 0, $class_name_length, true ) 4064 ) { 4065 $this->classname_updates[ $updated_name ] = self::ADD_CLASS; 4066 return true; 4067 } 4068 } 4069 4070 $this->classname_updates[ $class_name ] = self::ADD_CLASS; 4071 return true; 4072 } 4073 4074 /** 4075 * Removes a class name from the currently matched tag. 4076 * 4077 * @since 6.2.0 4078 * 4079 * @param string $class_name The class name to remove. 4080 * @return bool Whether the class was set to be removed. 4081 */ 4082 public function remove_class( $class_name ): bool { 4083 if ( 4084 self::STATE_MATCHED_TAG !== $this->parser_state || 4085 $this->is_closing_tag 4086 ) { 4087 return false; 4088 } 4089 4090 if ( self::QUIRKS_MODE !== $this->compat_mode ) { 4091 $this->classname_updates[ $class_name ] = self::REMOVE_CLASS; 4092 return true; 4093 } 4094 4095 /* 4096 * Because class names are matched ASCII-case-insensitively in quirks mode, 4097 * this needs to see if a case variant of the given class name is already 4098 * enqueued and update that existing entry, if so. This picks the casing of 4099 * the first-provided class name for all lexical variations. 4100 */ 4101 $class_name_length = strlen( $class_name ); 4102 foreach ( $this->classname_updates as $updated_name => $action ) { 4103 if ( 4104 strlen( $updated_name ) === $class_name_length && 4105 0 === substr_compare( $updated_name, $class_name, 0, $class_name_length, true ) 4106 ) { 4107 $this->classname_updates[ $updated_name ] = self::REMOVE_CLASS; 4108 return true; 4109 } 4110 } 4111 4112 $this->classname_updates[ $class_name ] = self::REMOVE_CLASS; 4113 return true; 4114 } 4115 4116 /** 4117 * Returns the string representation of the HTML Tag Processor. 4118 * 4119 * @since 6.2.0 4120 * 4121 * @see WP_HTML_Tag_Processor::get_updated_html() 4122 * 4123 * @return string The processed HTML. 4124 */ 4125 public function __toString(): string { 4126 return $this->get_updated_html(); 4127 } 4128 4129 /** 4130 * Returns the string representation of the HTML Tag Processor. 4131 * 4132 * @since 6.2.0 4133 * @since 6.2.1 Shifts the internal cursor corresponding to the applied updates. 4134 * @since 6.4.0 No longer calls subclass method `next_tag()` after updating HTML. 4135 * 4136 * @return string The processed HTML. 4137 */ 4138 public function get_updated_html(): string { 4139 $requires_no_updating = 0 === count( $this->classname_updates ) && 0 === count( $this->lexical_updates ); 4140 4141 /* 4142 * When there is nothing more to update and nothing has already been 4143 * updated, return the original document and avoid a string copy. 4144 */ 4145 if ( $requires_no_updating ) { 4146 return $this->html; 4147 } 4148 4149 /* 4150 * Keep track of the position right before the current tag. This will 4151 * be necessary for reparsing the current tag after updating the HTML. 4152 */ 4153 $before_current_tag = $this->token_starts_at ?? 0; 4154 4155 /* 4156 * 1. Apply the enqueued edits and update all the pointers to reflect those changes. 4157 */ 4158 $this->class_name_updates_to_attributes_updates(); 4159 $before_current_tag += $this->apply_attributes_updates( $before_current_tag ); 4160 4161 /* 4162 * 2. Rewind to before the current tag and reparse to get updated attributes. 4163 * 4164 * At this point the internal cursor points to the end of the tag name. 4165 * Rewind before the tag name starts so that it's as if the cursor didn't 4166 * move; a call to `next_tag()` will reparse the recently-updated attributes 4167 * and additional calls to modify the attributes will apply at this same 4168 * location, but in order to avoid issues with subclasses that might add 4169 * behaviors to `next_tag()`, the internal methods should be called here 4170 * instead. 4171 * 4172 * It's important to note that in this specific place there will be no change 4173 * because the processor was already at a tag when this was called and it's 4174 * rewinding only to the beginning of this very tag before reprocessing it 4175 * and its attributes. 4176 * 4177 * <p>Previous HTML<em>More HTML</em></p> 4178 * ↑ │ back up by the length of the tag name plus the opening < 4179 * └←─┘ back up by strlen("em") + 1 ==> 3 4180 */ 4181 $this->bytes_already_parsed = $before_current_tag; 4182 $this->base_class_next_token(); 4183 4184 return $this->html; 4185 } 4186 4187 /** 4188 * Parses tag query input into internal search criteria. 4189 * 4190 * @since 6.2.0 4191 * 4192 * @param array|string|null $query { 4193 * Optional. Which tag name to find, having which class, etc. Default is to find any tag. 4194 * 4195 * @type string|null $tag_name Which tag to find, or `null` for "any tag." 4196 * @type int|null $match_offset Find the Nth tag matching all search criteria. 4197 * 1 for "first" tag, 3 for "third," etc. 4198 * Defaults to first tag. 4199 * @type string|null $class_name Tag must contain this class name to match. 4200 * @type string $tag_closers "visit" or "skip": whether to stop on tag closers, e.g. </div>. 4201 * } 4202 */ 4203 private function parse_query( $query ) { 4204 if ( null !== $query && $query === $this->last_query ) { 4205 return; 4206 } 4207 4208 $this->last_query = $query; 4209 $this->sought_tag_name = null; 4210 $this->sought_class_name = null; 4211 $this->sought_match_offset = 1; 4212 $this->stop_on_tag_closers = false; 4213 4214 // A single string value means "find the tag of this name". 4215 if ( is_string( $query ) ) { 4216 $this->sought_tag_name = $query; 4217 return; 4218 } 4219 4220 // An empty query parameter applies no restrictions on the search. 4221 if ( null === $query ) { 4222 return; 4223 } 4224 4225 // If not using the string interface, an associative array is required. 4226 if ( ! is_array( $query ) ) { 4227 _doing_it_wrong( 4228 __METHOD__, 4229 __( 'The query argument must be an array or a tag name.' ), 4230 '6.2.0' 4231 ); 4232 return; 4233 } 4234 4235 if ( isset( $query['tag_name'] ) && is_string( $query['tag_name'] ) ) { 4236 $this->sought_tag_name = $query['tag_name']; 4237 } 4238 4239 if ( isset( $query['class_name'] ) && is_string( $query['class_name'] ) ) { 4240 $this->sought_class_name = $query['class_name']; 4241 } 4242 4243 if ( isset( $query['match_offset'] ) && is_int( $query['match_offset'] ) && 0 < $query['match_offset'] ) { 4244 $this->sought_match_offset = $query['match_offset']; 4245 } 4246 4247 if ( isset( $query['tag_closers'] ) ) { 4248 $this->stop_on_tag_closers = 'visit' === $query['tag_closers']; 4249 } 4250 } 4251 4252 4253 /** 4254 * Checks whether a given tag and its attributes match the search criteria. 4255 * 4256 * @since 6.2.0 4257 * 4258 * @return bool Whether the given tag and its attribute match the search criteria. 4259 */ 4260 private function matches(): bool { 4261 if ( $this->is_closing_tag && ! $this->stop_on_tag_closers ) { 4262 return false; 4263 } 4264 4265 // Does the tag name match the requested tag name in a case-insensitive manner? 4266 if ( 4267 isset( $this->sought_tag_name ) && 4268 ( 4269 strlen( $this->sought_tag_name ) !== $this->tag_name_length || 4270 0 !== substr_compare( $this->html, $this->sought_tag_name, $this->tag_name_starts_at, $this->tag_name_length, true ) 4271 ) 4272 ) { 4273 return false; 4274 } 4275 4276 if ( null !== $this->sought_class_name && ! $this->has_class( $this->sought_class_name ) ) { 4277 return false; 4278 } 4279 4280 return true; 4281 } 4282 4283 /** 4284 * Gets DOCTYPE declaration info from a DOCTYPE token. 4285 * 4286 * DOCTYPE tokens may appear in many places in an HTML document. In most places, they are 4287 * simply ignored. The main parsing functions find the basic shape of DOCTYPE tokens but 4288 * do not perform detailed parsing. 4289 * 4290 * This method can be called to perform a full parse of the DOCTYPE token and retrieve 4291 * its information. 4292 * 4293 * @return WP_HTML_Doctype_Info|null The DOCTYPE declaration information or `null` if not 4294 * currently at a DOCTYPE node. 4295 */ 4296 public function get_doctype_info(): ?WP_HTML_Doctype_Info { 4297 if ( self::STATE_DOCTYPE !== $this->parser_state ) { 4298 return null; 4299 } 4300 4301 return WP_HTML_Doctype_Info::from_doctype_token( substr( $this->html, $this->token_starts_at, $this->token_length ) ); 4302 } 4303 4304 /** 4305 * Parser Ready State. 4306 * 4307 * Indicates that the parser is ready to run and waiting for a state transition. 4308 * It may not have started yet, or it may have just finished parsing a token and 4309 * is ready to find the next one. 4310 * 4311 * @since 6.5.0 4312 * 4313 * @access private 4314 */ 4315 const STATE_READY = 'STATE_READY'; 4316 4317 /** 4318 * Parser Complete State. 4319 * 4320 * Indicates that the parser has reached the end of the document and there is 4321 * nothing left to scan. It finished parsing the last token completely. 4322 * 4323 * @since 6.5.0 4324 * 4325 * @access private 4326 */ 4327 const STATE_COMPLETE = 'STATE_COMPLETE'; 4328 4329 /** 4330 * Parser Incomplete Input State. 4331 * 4332 * Indicates that the parser has reached the end of the document before finishing 4333 * a token. It started parsing a token but there is a possibility that the input 4334 * HTML document was truncated in the middle of a token. 4335 * 4336 * The parser is reset at the start of the incomplete token and has paused. There 4337 * is nothing more than can be scanned unless provided a more complete document. 4338 * 4339 * @since 6.5.0 4340 * 4341 * @access private 4342 */ 4343 const STATE_INCOMPLETE_INPUT = 'STATE_INCOMPLETE_INPUT'; 4344 4345 /** 4346 * Parser Matched Tag State. 4347 * 4348 * Indicates that the parser has found an HTML tag and it's possible to get 4349 * the tag name and read or modify its attributes (if it's not a closing tag). 4350 * 4351 * @since 6.5.0 4352 * 4353 * @access private 4354 */ 4355 const STATE_MATCHED_TAG = 'STATE_MATCHED_TAG'; 4356 4357 /** 4358 * Parser Text Node State. 4359 * 4360 * Indicates that the parser has found a text node and it's possible 4361 * to read and modify that text. 4362 * 4363 * @since 6.5.0 4364 * 4365 * @access private 4366 */ 4367 const STATE_TEXT_NODE = 'STATE_TEXT_NODE'; 4368 4369 /** 4370 * Parser CDATA Node State. 4371 * 4372 * Indicates that the parser has found a CDATA node and it's possible 4373 * to read and modify its modifiable text. Note that in HTML there are 4374 * no CDATA nodes outside of foreign content (SVG and MathML). Outside 4375 * of foreign content, they are treated as HTML comments. 4376 * 4377 * @since 6.5.0 4378 * 4379 * @access private 4380 */ 4381 const STATE_CDATA_NODE = 'STATE_CDATA_NODE'; 4382 4383 /** 4384 * Indicates that the parser has found an HTML comment and it's 4385 * possible to read and modify its modifiable text. 4386 * 4387 * @since 6.5.0 4388 * 4389 * @access private 4390 */ 4391 const STATE_COMMENT = 'STATE_COMMENT'; 4392 4393 /** 4394 * Indicates that the parser has found a DOCTYPE node and it's 4395 * possible to read its DOCTYPE information via `get_doctype_info()`. 4396 * 4397 * @since 6.5.0 4398 * 4399 * @access private 4400 */ 4401 const STATE_DOCTYPE = 'STATE_DOCTYPE'; 4402 4403 /** 4404 * Indicates that the parser has found an empty tag closer `</>`. 4405 * 4406 * Note that in HTML there are no empty tag closers, and they 4407 * are ignored. Nonetheless, the Tag Processor still 4408 * recognizes them as they appear in the HTML stream. 4409 * 4410 * These were historically discussed as a "presumptuous tag 4411 * closer," which would close the nearest open tag, but were 4412 * dismissed in favor of explicitly-closing tags. 4413 * 4414 * @since 6.5.0 4415 * 4416 * @access private 4417 */ 4418 const STATE_PRESUMPTUOUS_TAG = 'STATE_PRESUMPTUOUS_TAG'; 4419 4420 /** 4421 * Indicates that the parser has found a "funky comment" 4422 * and it's possible to read and modify its modifiable text. 4423 * 4424 * Example: 4425 * 4426 * </%url> 4427 * </{"wp-bit":"query/post-author"}> 4428 * </2> 4429 * 4430 * Funky comments are tag closers with invalid tag names. Note 4431 * that in HTML these are turn into bogus comments. Nonetheless, 4432 * the Tag Processor recognizes them in a stream of HTML and 4433 * exposes them for inspection and modification. 4434 * 4435 * @since 6.5.0 4436 * 4437 * @access private 4438 */ 4439 const STATE_FUNKY_COMMENT = 'STATE_WP_FUNKY'; 4440 4441 /** 4442 * Indicates that a comment was created when encountering abruptly-closed HTML comment. 4443 * 4444 * Example: 4445 * 4446 * <!--> 4447 * <!---> 4448 * 4449 * @since 6.5.0 4450 */ 4451 const COMMENT_AS_ABRUPTLY_CLOSED_COMMENT = 'COMMENT_AS_ABRUPTLY_CLOSED_COMMENT'; 4452 4453 /** 4454 * Indicates that a comment would be parsed as a CDATA node, 4455 * were HTML to allow CDATA nodes outside of foreign content. 4456 * 4457 * Example: 4458 * 4459 * <![CDATA[This is a CDATA node.]]> 4460 * 4461 * This is an HTML comment, but it looks like a CDATA node. 4462 * 4463 * @since 6.5.0 4464 */ 4465 const COMMENT_AS_CDATA_LOOKALIKE = 'COMMENT_AS_CDATA_LOOKALIKE'; 4466 4467 /** 4468 * Indicates that a comment was created when encountering 4469 * normative HTML comment syntax. 4470 * 4471 * Example: 4472 * 4473 * <!-- this is a comment --> 4474 * 4475 * @since 6.5.0 4476 */ 4477 const COMMENT_AS_HTML_COMMENT = 'COMMENT_AS_HTML_COMMENT'; 4478 4479 /** 4480 * Indicates that a comment would be parsed as a Processing 4481 * Instruction node, were they to exist within HTML. 4482 * 4483 * Example: 4484 * 4485 * <?wp __( 'Like' ) ?> 4486 * 4487 * This is an HTML comment, but it looks like a CDATA node. 4488 * 4489 * @since 6.5.0 4490 */ 4491 const COMMENT_AS_PI_NODE_LOOKALIKE = 'COMMENT_AS_PI_NODE_LOOKALIKE'; 4492 4493 /** 4494 * Indicates that a comment was created when encountering invalid 4495 * HTML input, a so-called "bogus comment." 4496 * 4497 * Example: 4498 * 4499 * <?nothing special> 4500 * <!{nothing special}> 4501 * 4502 * @since 6.5.0 4503 */ 4504 const COMMENT_AS_INVALID_HTML = 'COMMENT_AS_INVALID_HTML'; 4505 4506 /** 4507 * No-quirks mode document compatability mode. 4508 * 4509 * > In no-quirks mode, the behavior is (hopefully) the desired behavior 4510 * > described by the modern HTML and CSS specifications. 4511 * 4512 * @see self::$compat_mode 4513 * @see https://developer.mozilla.org/en-US/docs/Web/HTML/Quirks_Mode_and_Standards_Mode 4514 * 4515 * @since 6.7.0 4516 * 4517 * @var string 4518 */ 4519 const NO_QUIRKS_MODE = 'no-quirks-mode'; 4520 4521 /** 4522 * Quirks mode document compatability mode. 4523 * 4524 * > In quirks mode, layout emulates behavior in Navigator 4 and Internet 4525 * > Explorer 5. This is essential in order to support websites that were 4526 * > built before the widespread adoption of web standards. 4527 * 4528 * @see self::$compat_mode 4529 * @see https://developer.mozilla.org/en-US/docs/Web/HTML/Quirks_Mode_and_Standards_Mode 4530 * 4531 * @since 6.7.0 4532 * 4533 * @var string 4534 */ 4535 const QUIRKS_MODE = 'quirks-mode'; 4536 4537 /** 4538 * Indicates that a span of text may contain any combination of significant 4539 * kinds of characters: NULL bytes, whitespace, and others. 4540 * 4541 * @see self::$text_node_classification 4542 * @see self::subdivide_text_appropriately 4543 * 4544 * @since 6.7.0 4545 */ 4546 const TEXT_IS_GENERIC = 'TEXT_IS_GENERIC'; 4547 4548 /** 4549 * Indicates that a span of text comprises a sequence only of NULL bytes. 4550 * 4551 * @see self::$text_node_classification 4552 * @see self::subdivide_text_appropriately 4553 * 4554 * @since 6.7.0 4555 */ 4556 const TEXT_IS_NULL_SEQUENCE = 'TEXT_IS_NULL_SEQUENCE'; 4557 4558 /** 4559 * Indicates that a span of decoded text comprises only whitespace. 4560 * 4561 * @see self::$text_node_classification 4562 * @see self::subdivide_text_appropriately 4563 * 4564 * @since 6.7.0 4565 */ 4566 const TEXT_IS_WHITESPACE = 'TEXT_IS_WHITESPACE'; 4567 }
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