File: /var/www/vhosts/uyarreklam.com.tr/httpdocs/html-api.tar
class-wp-html-active-formatting-elements.php 0000644 00000013206 15153115175 0015211 0 ustar 00 <?php
/**
* HTML API: WP_HTML_Active_Formatting_Elements class
*
* @package WordPress
* @subpackage HTML-API
* @since 6.4.0
*/
/**
* Core class used by the HTML processor during HTML parsing
* for managing the stack of active formatting elements.
*
* This class is designed for internal use by the HTML processor.
*
* > Initially, the list of active formatting elements is empty.
* > It is used to handle mis-nested formatting element tags.
* >
* > The list contains elements in the formatting category, and markers.
* > The markers are inserted when entering applet, object, marquee,
* > template, td, th, and caption elements, and are used to prevent
* > formatting from "leaking" into applet, object, marquee, template,
* > td, th, and caption elements.
* >
* > In addition, each element in the list of active formatting elements
* > is associated with the token for which it was created, so that
* > further elements can be created for that token if necessary.
*
* @since 6.4.0
*
* @access private
*
* @see https://html.spec.whatwg.org/#list-of-active-formatting-elements
* @see WP_HTML_Processor
*/
class WP_HTML_Active_Formatting_Elements {
/**
* Holds the stack of active formatting element references.
*
* @since 6.4.0
*
* @var WP_HTML_Token[]
*/
private $stack = array();
/**
* Reports if a specific node is in the stack of active formatting elements.
*
* @since 6.4.0
*
* @param WP_HTML_Token $token Look for this node in the stack.
* @return bool Whether the referenced node is in the stack of active formatting elements.
*/
public function contains_node( $token ) {
foreach ( $this->walk_up() as $item ) {
if ( $token->bookmark_name === $item->bookmark_name ) {
return true;
}
}
return false;
}
/**
* Returns how many nodes are currently in the stack of active formatting elements.
*
* @since 6.4.0
*
* @return int How many node are in the stack of active formatting elements.
*/
public function count() {
return count( $this->stack );
}
/**
* Returns the node at the end of the stack of active formatting elements,
* if one exists. If the stack is empty, returns null.
*
* @since 6.4.0
*
* @return WP_HTML_Token|null Last node in the stack of active formatting elements, if one exists, otherwise null.
*/
public function current_node() {
$current_node = end( $this->stack );
return $current_node ? $current_node : null;
}
/**
* Pushes a node onto the stack of active formatting elements.
*
* @since 6.4.0
*
* @see https://html.spec.whatwg.org/#push-onto-the-list-of-active-formatting-elements
*
* @param WP_HTML_Token $token Push this node onto the stack.
*/
public function push( $token ) {
/*
* > If there are already three elements in the list of active formatting elements after the last marker,
* > if any, or anywhere in the list if there are no markers, that have the same tag name, namespace, and
* > attributes as element, then remove the earliest such element from the list of active formatting
* > elements. For these purposes, the attributes must be compared as they were when the elements were
* > created by the parser; two elements have the same attributes if all their parsed attributes can be
* > paired such that the two attributes in each pair have identical names, namespaces, and values
* > (the order of the attributes does not matter).
*
* @todo Implement the "Noah's Ark clause" to only add up to three of any given kind of formatting elements to the stack.
*/
// > Add element to the list of active formatting elements.
$this->stack[] = $token;
}
/**
* Removes a node from the stack of active formatting elements.
*
* @since 6.4.0
*
* @param WP_HTML_Token $token Remove this node from the stack, if it's there already.
* @return bool Whether the node was found and removed from the stack of active formatting elements.
*/
public function remove_node( $token ) {
foreach ( $this->walk_up() as $position_from_end => $item ) {
if ( $token->bookmark_name !== $item->bookmark_name ) {
continue;
}
$position_from_start = $this->count() - $position_from_end - 1;
array_splice( $this->stack, $position_from_start, 1 );
return true;
}
return false;
}
/**
* Steps through the stack of active formatting elements, starting with the
* top element (added first) and walking downwards to the one added last.
*
* This generator function is designed to be used inside a "foreach" loop.
*
* Example:
*
* $html = '<em><strong><a>We are here';
* foreach ( $stack->walk_down() as $node ) {
* echo "{$node->node_name} -> ";
* }
* > EM -> STRONG -> A ->
*
* To start with the most-recently added element and walk towards the top,
* see WP_HTML_Active_Formatting_Elements::walk_up().
*
* @since 6.4.0
*/
public function walk_down() {
$count = count( $this->stack );
for ( $i = 0; $i < $count; $i++ ) {
yield $this->stack[ $i ];
}
}
/**
* Steps through the stack of active formatting elements, starting with the
* bottom element (added last) and walking upwards to the one added first.
*
* This generator function is designed to be used inside a "foreach" loop.
*
* Example:
*
* $html = '<em><strong><a>We are here';
* foreach ( $stack->walk_up() as $node ) {
* echo "{$node->node_name} -> ";
* }
* > A -> STRONG -> EM ->
*
* To start with the first added element and walk towards the bottom,
* see WP_HTML_Active_Formatting_Elements::walk_down().
*
* @since 6.4.0
*/
public function walk_up() {
for ( $i = count( $this->stack ) - 1; $i >= 0; $i-- ) {
yield $this->stack[ $i ];
}
}
}
class-wp-html-attribute-token.php 0000644 00000005327 15153115176 0013103 0 ustar 00 <?php
/**
* HTML API: WP_HTML_Attribute_Token class
*
* @package WordPress
* @subpackage HTML-API
* @since 6.2.0
*/
/**
* Core class used by the HTML tag processor as a data structure for the attribute token,
* allowing to drastically improve performance.
*
* This class is for internal usage of the WP_HTML_Tag_Processor class.
*
* @access private
* @since 6.2.0
* @since 6.5.0 Replaced `end` with `length` to more closely match `substr()`.
*
* @see WP_HTML_Tag_Processor
*/
class WP_HTML_Attribute_Token {
/**
* Attribute name.
*
* @since 6.2.0
*
* @var string
*/
public $name;
/**
* Attribute value.
*
* @since 6.2.0
*
* @var int
*/
public $value_starts_at;
/**
* How many bytes the value occupies in the input HTML.
*
* @since 6.2.0
*
* @var int
*/
public $value_length;
/**
* The string offset where the attribute name starts.
*
* @since 6.2.0
*
* @var int
*/
public $start;
/**
* Byte length of text spanning the attribute inside a tag.
*
* This span starts at the first character of the attribute name
* and it ends after one of three cases:
*
* - at the end of the attribute name for boolean attributes.
* - at the end of the value for unquoted attributes.
* - at the final single or double quote for quoted attributes.
*
* Example:
*
* <div class="post">
* ------------ length is 12, including quotes
*
* <input type="checked" checked id="selector">
* ------- length is 6
*
* <a rel=noopener>
* ------------ length is 11
*
* @since 6.5.0 Replaced `end` with `length` to more closely match `substr()`.
*
* @var int
*/
public $length;
/**
* Whether the attribute is a boolean attribute with value `true`.
*
* @since 6.2.0
*
* @var bool
*/
public $is_true;
/**
* Constructor.
*
* @since 6.2.0
* @since 6.5.0 Replaced `end` with `length` to more closely match `substr()`.
*
* @param string $name Attribute name.
* @param int $value_start Attribute value.
* @param int $value_length Number of bytes attribute value spans.
* @param int $start The string offset where the attribute name starts.
* @param int $length Byte length of the entire attribute name or name and value pair expression.
* @param bool $is_true Whether the attribute is a boolean attribute with true value.
*/
public function __construct( $name, $value_start, $value_length, $start, $length, $is_true ) {
$this->name = $name;
$this->value_starts_at = $value_start;
$this->value_length = $value_length;
$this->start = $start;
$this->length = $length;
$this->is_true = $is_true;
}
}
class-wp-html-open-elements.php 0000644 00000030571 15153115176 0012534 0 ustar 00 <?php
/**
* HTML API: WP_HTML_Open_Elements class
*
* @package WordPress
* @subpackage HTML-API
* @since 6.4.0
*/
/**
* Core class used by the HTML processor during HTML parsing
* for managing the stack of open elements.
*
* This class is designed for internal use by the HTML processor.
*
* > Initially, the stack of open elements is empty. The stack grows
* > downwards; the topmost node on the stack is the first one added
* > to the stack, and the bottommost node of the stack is the most
* > recently added node in the stack (notwithstanding when the stack
* > is manipulated in a random access fashion as part of the handling
* > for misnested tags).
*
* @since 6.4.0
*
* @access private
*
* @see https://html.spec.whatwg.org/#stack-of-open-elements
* @see WP_HTML_Processor
*/
class WP_HTML_Open_Elements {
/**
* Holds the stack of open element references.
*
* @since 6.4.0
*
* @var WP_HTML_Token[]
*/
public $stack = array();
/**
* Whether a P element is in button scope currently.
*
* This class optimizes scope lookup by pre-calculating
* this value when elements are added and removed to the
* stack of open elements which might change its value.
* This avoids frequent iteration over the stack.
*
* @since 6.4.0
*
* @var bool
*/
private $has_p_in_button_scope = false;
/**
* Reports if a specific node is in the stack of open elements.
*
* @since 6.4.0
*
* @param WP_HTML_Token $token Look for this node in the stack.
* @return bool Whether the referenced node is in the stack of open elements.
*/
public function contains_node( $token ) {
foreach ( $this->walk_up() as $item ) {
if ( $token->bookmark_name === $item->bookmark_name ) {
return true;
}
}
return false;
}
/**
* Returns how many nodes are currently in the stack of open elements.
*
* @since 6.4.0
*
* @return int How many node are in the stack of open elements.
*/
public function count() {
return count( $this->stack );
}
/**
* Returns the node at the end of the stack of open elements,
* if one exists. If the stack is empty, returns null.
*
* @since 6.4.0
*
* @return WP_HTML_Token|null Last node in the stack of open elements, if one exists, otherwise null.
*/
public function current_node() {
$current_node = end( $this->stack );
return $current_node ? $current_node : null;
}
/**
* Returns whether an element is in a specific scope.
*
* ## HTML Support
*
* This function skips checking for the termination list because there
* are no supported elements which appear in the termination list.
*
* @since 6.4.0
*
* @see https://html.spec.whatwg.org/#has-an-element-in-the-specific-scope
*
* @param string $tag_name Name of tag check.
* @param string[] $termination_list List of elements that terminate the search.
* @return bool Whether the element was found in a specific scope.
*/
public function has_element_in_specific_scope( $tag_name, $termination_list ) {
foreach ( $this->walk_up() as $node ) {
if ( $node->node_name === $tag_name ) {
return true;
}
if (
'(internal: H1 through H6 - do not use)' === $tag_name &&
in_array( $node->node_name, array( 'H1', 'H2', 'H3', 'H4', 'H5', 'H6' ), true )
) {
return true;
}
switch ( $node->node_name ) {
case 'HTML':
return false;
}
if ( in_array( $node->node_name, $termination_list, true ) ) {
return false;
}
}
return false;
}
/**
* Returns whether a particular element is in scope.
*
* @since 6.4.0
*
* @see https://html.spec.whatwg.org/#has-an-element-in-scope
*
* @param string $tag_name Name of tag to check.
* @return bool Whether given element is in scope.
*/
public function has_element_in_scope( $tag_name ) {
return $this->has_element_in_specific_scope(
$tag_name,
array(
/*
* Because it's not currently possible to encounter
* one of the termination elements, they don't need
* to be listed here. If they were, they would be
* unreachable and only waste CPU cycles while
* scanning through HTML.
*/
)
);
}
/**
* Returns whether a particular element is in list item scope.
*
* @since 6.4.0
* @since 6.5.0 Implemented: no longer throws on every invocation.
*
* @see https://html.spec.whatwg.org/#has-an-element-in-list-item-scope
*
* @param string $tag_name Name of tag to check.
* @return bool Whether given element is in scope.
*/
public function has_element_in_list_item_scope( $tag_name ) {
return $this->has_element_in_specific_scope(
$tag_name,
array(
// There are more elements that belong here which aren't currently supported.
'OL',
'UL',
)
);
}
/**
* Returns whether a particular element is in button scope.
*
* @since 6.4.0
*
* @see https://html.spec.whatwg.org/#has-an-element-in-button-scope
*
* @param string $tag_name Name of tag to check.
* @return bool Whether given element is in scope.
*/
public function has_element_in_button_scope( $tag_name ) {
return $this->has_element_in_specific_scope( $tag_name, array( 'BUTTON' ) );
}
/**
* Returns whether a particular element is in table scope.
*
* @since 6.4.0
*
* @see https://html.spec.whatwg.org/#has-an-element-in-table-scope
*
* @throws WP_HTML_Unsupported_Exception Always until this function is implemented.
*
* @param string $tag_name Name of tag to check.
* @return bool Whether given element is in scope.
*/
public function has_element_in_table_scope( $tag_name ) {
throw new WP_HTML_Unsupported_Exception( 'Cannot process elements depending on table scope.' );
return false; // The linter requires this unreachable code until the function is implemented and can return.
}
/**
* Returns whether a particular element is in select scope.
*
* @since 6.4.0
*
* @see https://html.spec.whatwg.org/#has-an-element-in-select-scope
*
* @throws WP_HTML_Unsupported_Exception Always until this function is implemented.
*
* @param string $tag_name Name of tag to check.
* @return bool Whether given element is in scope.
*/
public function has_element_in_select_scope( $tag_name ) {
throw new WP_HTML_Unsupported_Exception( 'Cannot process elements depending on select scope.' );
return false; // The linter requires this unreachable code until the function is implemented and can return.
}
/**
* Returns whether a P is in BUTTON scope.
*
* @since 6.4.0
*
* @see https://html.spec.whatwg.org/#has-an-element-in-button-scope
*
* @return bool Whether a P is in BUTTON scope.
*/
public function has_p_in_button_scope() {
return $this->has_p_in_button_scope;
}
/**
* Pops a node off of the stack of open elements.
*
* @since 6.4.0
*
* @see https://html.spec.whatwg.org/#stack-of-open-elements
*
* @return bool Whether a node was popped off of the stack.
*/
public function pop() {
$item = array_pop( $this->stack );
if ( null === $item ) {
return false;
}
$this->after_element_pop( $item );
return true;
}
/**
* Pops nodes off of the stack of open elements until one with the given tag name has been popped.
*
* @since 6.4.0
*
* @see WP_HTML_Open_Elements::pop
*
* @param string $tag_name Name of tag that needs to be popped off of the stack of open elements.
* @return bool Whether a tag of the given name was found and popped off of the stack of open elements.
*/
public function pop_until( $tag_name ) {
foreach ( $this->walk_up() as $item ) {
$this->pop();
if (
'(internal: H1 through H6 - do not use)' === $tag_name &&
in_array( $item->node_name, array( 'H1', 'H2', 'H3', 'H4', 'H5', 'H6' ), true )
) {
return true;
}
if ( $tag_name === $item->node_name ) {
return true;
}
}
return false;
}
/**
* Pushes a node onto the stack of open elements.
*
* @since 6.4.0
*
* @see https://html.spec.whatwg.org/#stack-of-open-elements
*
* @param WP_HTML_Token $stack_item Item to add onto stack.
*/
public function push( $stack_item ) {
$this->stack[] = $stack_item;
$this->after_element_push( $stack_item );
}
/**
* Removes a specific node from the stack of open elements.
*
* @since 6.4.0
*
* @param WP_HTML_Token $token The node to remove from the stack of open elements.
* @return bool Whether the node was found and removed from the stack of open elements.
*/
public function remove_node( $token ) {
foreach ( $this->walk_up() as $position_from_end => $item ) {
if ( $token->bookmark_name !== $item->bookmark_name ) {
continue;
}
$position_from_start = $this->count() - $position_from_end - 1;
array_splice( $this->stack, $position_from_start, 1 );
$this->after_element_pop( $item );
return true;
}
return false;
}
/**
* Steps through the stack of open elements, starting with the top element
* (added first) and walking downwards to the one added last.
*
* This generator function is designed to be used inside a "foreach" loop.
*
* Example:
*
* $html = '<em><strong><a>We are here';
* foreach ( $stack->walk_down() as $node ) {
* echo "{$node->node_name} -> ";
* }
* > EM -> STRONG -> A ->
*
* To start with the most-recently added element and walk towards the top,
* see WP_HTML_Open_Elements::walk_up().
*
* @since 6.4.0
*/
public function walk_down() {
$count = count( $this->stack );
for ( $i = 0; $i < $count; $i++ ) {
yield $this->stack[ $i ];
}
}
/**
* Steps through the stack of open elements, starting with the bottom element
* (added last) and walking upwards to the one added first.
*
* This generator function is designed to be used inside a "foreach" loop.
*
* Example:
*
* $html = '<em><strong><a>We are here';
* foreach ( $stack->walk_up() as $node ) {
* echo "{$node->node_name} -> ";
* }
* > A -> STRONG -> EM ->
*
* To start with the first added element and walk towards the bottom,
* see WP_HTML_Open_Elements::walk_down().
*
* @since 6.4.0
* @since 6.5.0 Accepts $above_this_node to start traversal above a given node, if it exists.
*
* @param ?WP_HTML_Token $above_this_node Start traversing above this node, if provided and if the node exists.
*/
public function walk_up( $above_this_node = null ) {
$has_found_node = null === $above_this_node;
for ( $i = count( $this->stack ) - 1; $i >= 0; $i-- ) {
$node = $this->stack[ $i ];
if ( ! $has_found_node ) {
$has_found_node = $node === $above_this_node;
continue;
}
yield $node;
}
}
/*
* Internal helpers.
*/
/**
* Updates internal flags after adding an element.
*
* Certain conditions (such as "has_p_in_button_scope") are maintained here as
* flags that are only modified when adding and removing elements. This allows
* the HTML Processor to quickly check for these conditions instead of iterating
* over the open stack elements upon each new tag it encounters. These flags,
* however, need to be maintained as items are added and removed from the stack.
*
* @since 6.4.0
*
* @param WP_HTML_Token $item Element that was added to the stack of open elements.
*/
public function after_element_push( $item ) {
/*
* When adding support for new elements, expand this switch to trap
* cases where the precalculated value needs to change.
*/
switch ( $item->node_name ) {
case 'BUTTON':
$this->has_p_in_button_scope = false;
break;
case 'P':
$this->has_p_in_button_scope = true;
break;
}
}
/**
* Updates internal flags after removing an element.
*
* Certain conditions (such as "has_p_in_button_scope") are maintained here as
* flags that are only modified when adding and removing elements. This allows
* the HTML Processor to quickly check for these conditions instead of iterating
* over the open stack elements upon each new tag it encounters. These flags,
* however, need to be maintained as items are added and removed from the stack.
*
* @since 6.4.0
*
* @param WP_HTML_Token $item Element that was removed from the stack of open elements.
*/
public function after_element_pop( $item ) {
/*
* When adding support for new elements, expand this switch to trap
* cases where the precalculated value needs to change.
*/
switch ( $item->node_name ) {
case 'BUTTON':
$this->has_p_in_button_scope = $this->has_element_in_button_scope( 'P' );
break;
case 'P':
$this->has_p_in_button_scope = $this->has_element_in_button_scope( 'P' );
break;
}
}
}
class-wp-html-processor-state.php 0000644 00000006402 15153115177 0013113 0 ustar 00 <?php
/**
* HTML API: WP_HTML_Processor_State class
*
* @package WordPress
* @subpackage HTML-API
* @since 6.4.0
*/
/**
* Core class used by the HTML processor during HTML parsing
* for managing the internal parsing state.
*
* This class is designed for internal use by the HTML processor.
*
* @since 6.4.0
*
* @access private
*
* @see WP_HTML_Processor
*/
class WP_HTML_Processor_State {
/*
* Insertion mode constants.
*
* These constants exist and are named to make it easier to
* discover and recognize the supported insertion modes in
* the parser.
*
* Out of all the possible insertion modes, only those
* supported by the parser are listed here. As support
* is added to the parser for more modes, add them here
* following the same naming and value pattern.
*
* @see https://html.spec.whatwg.org/#the-insertion-mode
*/
/**
* Initial insertion mode for full HTML parser.
*
* @since 6.4.0
*
* @see https://html.spec.whatwg.org/#the-initial-insertion-mode
* @see WP_HTML_Processor_State::$insertion_mode
*
* @var string
*/
const INSERTION_MODE_INITIAL = 'insertion-mode-initial';
/**
* In body insertion mode for full HTML parser.
*
* @since 6.4.0
*
* @see https://html.spec.whatwg.org/#parsing-main-inbody
* @see WP_HTML_Processor_State::$insertion_mode
*
* @var string
*/
const INSERTION_MODE_IN_BODY = 'insertion-mode-in-body';
/**
* Tracks open elements while scanning HTML.
*
* This property is initialized in the constructor and never null.
*
* @since 6.4.0
*
* @see https://html.spec.whatwg.org/#stack-of-open-elements
*
* @var WP_HTML_Open_Elements
*/
public $stack_of_open_elements = null;
/**
* Tracks open formatting elements, used to handle mis-nested formatting element tags.
*
* This property is initialized in the constructor and never null.
*
* @since 6.4.0
*
* @see https://html.spec.whatwg.org/#list-of-active-formatting-elements
*
* @var WP_HTML_Active_Formatting_Elements
*/
public $active_formatting_elements = null;
/**
* Refers to the currently-matched tag, if any.
*
* @since 6.4.0
*
* @var WP_HTML_Token|null
*/
public $current_token = null;
/**
* Tree construction insertion mode.
*
* @since 6.4.0
*
* @see https://html.spec.whatwg.org/#insertion-mode
*
* @var string
*/
public $insertion_mode = self::INSERTION_MODE_INITIAL;
/**
* Context node initializing fragment parser, if created as a fragment parser.
*
* @since 6.4.0
*
* @see https://html.spec.whatwg.org/#concept-frag-parse-context
*
* @var [string, array]|null
*/
public $context_node = null;
/**
* The frameset-ok flag indicates if a `FRAMESET` element is allowed in the current state.
*
* > The frameset-ok flag is set to "ok" when the parser is created. It is set to "not ok" after certain tokens are seen.
*
* @since 6.4.0
*
* @see https://html.spec.whatwg.org/#frameset-ok-flag
*
* @var bool
*/
public $frameset_ok = true;
/**
* Constructor - creates a new and empty state value.
*
* @since 6.4.0
*
* @see WP_HTML_Processor
*/
public function __construct() {
$this->stack_of_open_elements = new WP_HTML_Open_Elements();
$this->active_formatting_elements = new WP_HTML_Active_Formatting_Elements();
}
}
class-wp-html-processor.php 0000644 00000171626 15153115177 0012010 0 ustar 00 <?php
/**
* HTML API: WP_HTML_Processor class
*
* @package WordPress
* @subpackage HTML-API
* @since 6.4.0
*/
/**
* Core class used to safely parse and modify an HTML document.
*
* The HTML Processor class properly parses and modifies HTML5 documents.
*
* It supports a subset of the HTML5 specification, and when it encounters
* unsupported markup, it aborts early to avoid unintentionally breaking
* the document. The HTML Processor should never break an HTML document.
*
* While the `WP_HTML_Tag_Processor` is a valuable tool for modifying
* attributes on individual HTML tags, the HTML Processor is more capable
* and useful for the following operations:
*
* - Querying based on nested HTML structure.
*
* Eventually the HTML Processor will also support:
* - Wrapping a tag in surrounding HTML.
* - Unwrapping a tag by removing its parent.
* - Inserting and removing nodes.
* - Reading and changing inner content.
* - Navigating up or around HTML structure.
*
* ## Usage
*
* Use of this class requires three steps:
*
* 1. Call a static creator method with your input HTML document.
* 2. Find the location in the document you are looking for.
* 3. Request changes to the document at that location.
*
* Example:
*
* $processor = WP_HTML_Processor::create_fragment( $html );
* if ( $processor->next_tag( array( 'breadcrumbs' => array( 'DIV', 'FIGURE', 'IMG' ) ) ) ) {
* $processor->add_class( 'responsive-image' );
* }
*
* #### Breadcrumbs
*
* Breadcrumbs represent the stack of open elements from the root
* of the document or fragment down to the currently-matched node,
* if one is currently selected. Call WP_HTML_Processor::get_breadcrumbs()
* to inspect the breadcrumbs for a matched tag.
*
* Breadcrumbs can specify nested HTML structure and are equivalent
* to a CSS selector comprising tag names separated by the child
* combinator, such as "DIV > FIGURE > IMG".
*
* Since all elements find themselves inside a full HTML document
* when parsed, the return value from `get_breadcrumbs()` will always
* contain any implicit outermost elements. For example, when parsing
* with `create_fragment()` in the `BODY` context (the default), any
* tag in the given HTML document will contain `array( 'HTML', 'BODY', … )`
* in its breadcrumbs.
*
* Despite containing the implied outermost elements in their breadcrumbs,
* tags may be found with the shortest-matching breadcrumb query. That is,
* `array( 'IMG' )` matches all IMG elements and `array( 'P', 'IMG' )`
* matches all IMG elements directly inside a P element. To ensure that no
* partial matches erroneously match it's possible to specify in a query
* the full breadcrumb match all the way down from the root HTML element.
*
* Example:
*
* $html = '<figure><img><figcaption>A <em>lovely</em> day outside</figcaption></figure>';
* // ----- Matches here.
* $processor->next_tag( array( 'breadcrumbs' => array( 'FIGURE', 'IMG' ) ) );
*
* $html = '<figure><img><figcaption>A <em>lovely</em> day outside</figcaption></figure>';
* // ---- Matches here.
* $processor->next_tag( array( 'breadcrumbs' => array( 'FIGURE', 'FIGCAPTION', 'EM' ) ) );
*
* $html = '<div><img></div><img>';
* // ----- Matches here, because IMG must be a direct child of the implicit BODY.
* $processor->next_tag( array( 'breadcrumbs' => array( 'BODY', 'IMG' ) ) );
*
* ## HTML Support
*
* This class implements a small part of the HTML5 specification.
* It's designed to operate within its support and abort early whenever
* encountering circumstances it can't properly handle. This is
* the principle way in which this class remains as simple as possible
* without cutting corners and breaking compliance.
*
* ### Supported elements
*
* If any unsupported element appears in the HTML input the HTML Processor
* will abort early and stop all processing. This draconian measure ensures
* that the HTML Processor won't break any HTML it doesn't fully understand.
*
* The following list specifies the HTML tags that _are_ supported:
*
* - Containers: ADDRESS, BLOCKQUOTE, DETAILS, DIALOG, DIV, FOOTER, HEADER, MAIN, MENU, SPAN, SUMMARY.
* - Custom elements: All custom elements are supported. :)
* - Form elements: BUTTON, DATALIST, FIELDSET, INPUT, LABEL, LEGEND, METER, PROGRESS, SEARCH.
* - Formatting elements: B, BIG, CODE, EM, FONT, I, PRE, SMALL, STRIKE, STRONG, TT, U, WBR.
* - Heading elements: H1, H2, H3, H4, H5, H6, HGROUP.
* - Links: A.
* - Lists: DD, DL, DT, LI, OL, UL.
* - Media elements: AUDIO, CANVAS, EMBED, FIGCAPTION, FIGURE, IMG, MAP, PICTURE, SOURCE, TRACK, VIDEO.
* - Paragraph: BR, P.
* - Phrasing elements: ABBR, AREA, BDI, BDO, CITE, DATA, DEL, DFN, INS, MARK, OUTPUT, Q, SAMP, SUB, SUP, TIME, VAR.
* - Sectioning elements: ARTICLE, ASIDE, HR, NAV, SECTION.
* - Templating elements: SLOT.
* - Text decoration: RUBY.
* - Deprecated elements: ACRONYM, BLINK, CENTER, DIR, ISINDEX, KEYGEN, LISTING, MULTICOL, NEXTID, PARAM, SPACER.
*
* ### Supported markup
*
* Some kinds of non-normative HTML involve reconstruction of formatting elements and
* re-parenting of mis-nested elements. For example, a DIV tag found inside a TABLE
* may in fact belong _before_ the table in the DOM. If the HTML Processor encounters
* such a case it will stop processing.
*
* The following list specifies HTML markup that _is_ supported:
*
* - Markup involving only those tags listed above.
* - Fully-balanced and non-overlapping tags.
* - HTML with unexpected tag closers.
* - Some unbalanced or overlapping tags.
* - P tags after unclosed P tags.
* - BUTTON tags after unclosed BUTTON tags.
* - A tags after unclosed A tags that don't involve any active formatting elements.
*
* @since 6.4.0
*
* @see WP_HTML_Tag_Processor
* @see https://html.spec.whatwg.org/
*/
class WP_HTML_Processor extends WP_HTML_Tag_Processor {
/**
* The maximum number of bookmarks allowed to exist at any given time.
*
* HTML processing requires more bookmarks than basic tag processing,
* so this class constant from the Tag Processor is overwritten.
*
* @since 6.4.0
*
* @var int
*/
const MAX_BOOKMARKS = 100;
/**
* Holds the working state of the parser, including the stack of
* open elements and the stack of active formatting elements.
*
* Initialized in the constructor.
*
* @since 6.4.0
*
* @var WP_HTML_Processor_State
*/
private $state = null;
/**
* Used to create unique bookmark names.
*
* This class sets a bookmark for every tag in the HTML document that it encounters.
* The bookmark name is auto-generated and increments, starting with `1`. These are
* internal bookmarks and are automatically released when the referring WP_HTML_Token
* goes out of scope and is garbage-collected.
*
* @since 6.4.0
*
* @see WP_HTML_Processor::$release_internal_bookmark_on_destruct
*
* @var int
*/
private $bookmark_counter = 0;
/**
* Stores an explanation for why something failed, if it did.
*
* @see self::get_last_error
*
* @since 6.4.0
*
* @var string|null
*/
private $last_error = null;
/**
* Releases a bookmark when PHP garbage-collects its wrapping WP_HTML_Token instance.
*
* This function is created inside the class constructor so that it can be passed to
* the stack of open elements and the stack of active formatting elements without
* exposing it as a public method on the class.
*
* @since 6.4.0
*
* @var closure
*/
private $release_internal_bookmark_on_destruct = null;
/*
* Public Interface Functions
*/
/**
* Creates an HTML processor in the fragment parsing mode.
*
* Use this for cases where you are processing chunks of HTML that
* will be found within a bigger HTML document, such as rendered
* block output that exists within a post, `the_content` inside a
* rendered site layout.
*
* Fragment parsing occurs within a context, which is an HTML element
* that the document will eventually be placed in. It becomes important
* when special elements have different rules than others, such as inside
* a TEXTAREA or a TITLE tag where things that look like tags are text,
* or inside a SCRIPT tag where things that look like HTML syntax are JS.
*
* The context value should be a representation of the tag into which the
* HTML is found. For most cases this will be the body element. The HTML
* form is provided because a context element may have attributes that
* impact the parse, such as with a SCRIPT tag and its `type` attribute.
*
* ## Current HTML Support
*
* - The only supported context is `<body>`, which is the default value.
* - The only supported document encoding is `UTF-8`, which is the default value.
*
* @since 6.4.0
*
* @param string $html Input HTML fragment to process.
* @param string $context Context element for the fragment, must be default of `<body>`.
* @param string $encoding Text encoding of the document; must be default of 'UTF-8'.
* @return WP_HTML_Processor|null The created processor if successful, otherwise null.
*/
public static function create_fragment( $html, $context = '<body>', $encoding = 'UTF-8' ) {
if ( '<body>' !== $context || 'UTF-8' !== $encoding ) {
return null;
}
$processor = new self( $html, self::CONSTRUCTOR_UNLOCK_CODE );
$processor->state->context_node = array( 'BODY', array() );
$processor->state->insertion_mode = WP_HTML_Processor_State::INSERTION_MODE_IN_BODY;
// @todo Create "fake" bookmarks for non-existent but implied nodes.
$processor->bookmarks['root-node'] = new WP_HTML_Span( 0, 0 );
$processor->bookmarks['context-node'] = new WP_HTML_Span( 0, 0 );
$processor->state->stack_of_open_elements->push(
new WP_HTML_Token(
'root-node',
'HTML',
false
)
);
$processor->state->stack_of_open_elements->push(
new WP_HTML_Token(
'context-node',
$processor->state->context_node[0],
false
)
);
return $processor;
}
/**
* Constructor.
*
* Do not use this method. Use the static creator methods instead.
*
* @access private
*
* @since 6.4.0
*
* @see WP_HTML_Processor::create_fragment()
*
* @param string $html HTML to process.
* @param string|null $use_the_static_create_methods_instead This constructor should not be called manually.
*/
public function __construct( $html, $use_the_static_create_methods_instead = null ) {
parent::__construct( $html );
if ( self::CONSTRUCTOR_UNLOCK_CODE !== $use_the_static_create_methods_instead ) {
_doing_it_wrong(
__METHOD__,
sprintf(
/* translators: %s: WP_HTML_Processor::create_fragment(). */
__( 'Call %s to create an HTML Processor instead of calling the constructor directly.' ),
'<code>WP_HTML_Processor::create_fragment()</code>'
),
'6.4.0'
);
}
$this->state = new WP_HTML_Processor_State();
/*
* Create this wrapper so that it's possible to pass
* a private method into WP_HTML_Token classes without
* exposing it to any public API.
*/
$this->release_internal_bookmark_on_destruct = function ( $name ) {
parent::release_bookmark( $name );
};
}
/**
* Returns the last error, if any.
*
* Various situations lead to parsing failure but this class will
* return `false` in all those cases. To determine why something
* failed it's possible to request the last error. This can be
* helpful to know to distinguish whether a given tag couldn't
* be found or if content in the document caused the processor
* to give up and abort processing.
*
* Example
*
* $processor = WP_HTML_Processor::create_fragment( '<template><strong><button><em><p><em>' );
* false === $processor->next_tag();
* WP_HTML_Processor::ERROR_UNSUPPORTED === $processor->get_last_error();
*
* @since 6.4.0
*
* @see self::ERROR_UNSUPPORTED
* @see self::ERROR_EXCEEDED_MAX_BOOKMARKS
*
* @return string|null The last error, if one exists, otherwise null.
*/
public function get_last_error() {
return $this->last_error;
}
/**
* Finds the next tag matching the $query.
*
* @todo Support matching the class name and tag name.
*
* @since 6.4.0
*
* @throws Exception When unable to allocate a bookmark for the next token in the input HTML document.
*
* @param array|string|null $query {
* Optional. Which tag name to find, having which class, etc. Default is to find any tag.
*
* @type string|null $tag_name Which tag to find, or `null` for "any tag."
* @type int|null $match_offset Find the Nth tag matching all search criteria.
* 1 for "first" tag, 3 for "third," etc.
* Defaults to first tag.
* @type string|null $class_name Tag must contain this whole class name to match.
* @type string[] $breadcrumbs DOM sub-path at which element is found, e.g. `array( 'FIGURE', 'IMG' )`.
* May also contain the wildcard `*` which matches a single element, e.g. `array( 'SECTION', '*' )`.
* }
* @return bool Whether a tag was matched.
*/
public function next_tag( $query = null ) {
if ( null === $query ) {
while ( $this->step() ) {
if ( '#tag' !== $this->get_token_type() ) {
continue;
}
if ( ! $this->is_tag_closer() ) {
return true;
}
}
return false;
}
if ( is_string( $query ) ) {
$query = array( 'breadcrumbs' => array( $query ) );
}
if ( ! is_array( $query ) ) {
_doing_it_wrong(
__METHOD__,
__( 'Please pass a query array to this function.' ),
'6.4.0'
);
return false;
}
if ( ! ( array_key_exists( 'breadcrumbs', $query ) && is_array( $query['breadcrumbs'] ) ) ) {
while ( $this->step() ) {
if ( '#tag' !== $this->get_token_type() ) {
continue;
}
if ( ! $this->is_tag_closer() ) {
return true;
}
}
return false;
}
if ( isset( $query['tag_closers'] ) && 'visit' === $query['tag_closers'] ) {
_doing_it_wrong(
__METHOD__,
__( 'Cannot visit tag closers in HTML Processor.' ),
'6.4.0'
);
return false;
}
$breadcrumbs = $query['breadcrumbs'];
$match_offset = isset( $query['match_offset'] ) ? (int) $query['match_offset'] : 1;
while ( $match_offset > 0 && $this->step() ) {
if ( '#tag' !== $this->get_token_type() ) {
continue;
}
if ( $this->matches_breadcrumbs( $breadcrumbs ) && 0 === --$match_offset ) {
return true;
}
}
return false;
}
/**
* Ensures internal accounting is maintained for HTML semantic rules while
* the underlying Tag Processor class is seeking to a bookmark.
*
* This doesn't currently have a way to represent non-tags and doesn't process
* semantic rules for text nodes. For access to the raw tokens consider using
* WP_HTML_Tag_Processor instead.
*
* @since 6.5.0 Added for internal support; do not use.
*
* @access private
*
* @return bool
*/
public function next_token() {
return $this->step();
}
/**
* Indicates if the currently-matched tag matches the given breadcrumbs.
*
* A "*" represents a single tag wildcard, where any tag matches, but not no tags.
*
* At some point this function _may_ support a `**` syntax for matching any number
* of unspecified tags in the breadcrumb stack. This has been intentionally left
* out, however, to keep this function simple and to avoid introducing backtracking,
* which could open up surprising performance breakdowns.
*
* Example:
*
* $processor = WP_HTML_Processor::create_fragment( '<div><span><figure><img></figure></span></div>' );
* $processor->next_tag( 'img' );
* true === $processor->matches_breadcrumbs( array( 'figure', 'img' ) );
* true === $processor->matches_breadcrumbs( array( 'span', 'figure', 'img' ) );
* false === $processor->matches_breadcrumbs( array( 'span', 'img' ) );
* true === $processor->matches_breadcrumbs( array( 'span', '*', 'img' ) );
*
* @since 6.4.0
*
* @param string[] $breadcrumbs DOM sub-path at which element is found, e.g. `array( 'FIGURE', 'IMG' )`.
* May also contain the wildcard `*` which matches a single element, e.g. `array( 'SECTION', '*' )`.
* @return bool Whether the currently-matched tag is found at the given nested structure.
*/
public function matches_breadcrumbs( $breadcrumbs ) {
// Everything matches when there are zero constraints.
if ( 0 === count( $breadcrumbs ) ) {
return true;
}
// Start at the last crumb.
$crumb = end( $breadcrumbs );
if ( '*' !== $crumb && $this->get_tag() !== strtoupper( $crumb ) ) {
return false;
}
foreach ( $this->state->stack_of_open_elements->walk_up() as $node ) {
$crumb = strtoupper( current( $breadcrumbs ) );
if ( '*' !== $crumb && $node->node_name !== $crumb ) {
return false;
}
if ( false === prev( $breadcrumbs ) ) {
return true;
}
}
return false;
}
/**
* Steps through the HTML document and stop at the next tag, if any.
*
* @since 6.4.0
*
* @throws Exception When unable to allocate a bookmark for the next token in the input HTML document.
*
* @see self::PROCESS_NEXT_NODE
* @see self::REPROCESS_CURRENT_NODE
*
* @param string $node_to_process Whether to parse the next node or reprocess the current node.
* @return bool Whether a tag was matched.
*/
public function step( $node_to_process = self::PROCESS_NEXT_NODE ) {
// Refuse to proceed if there was a previous error.
if ( null !== $this->last_error ) {
return false;
}
if ( self::REPROCESS_CURRENT_NODE !== $node_to_process ) {
/*
* Void elements still hop onto the stack of open elements even though
* there's no corresponding closing tag. This is important for managing
* stack-based operations such as "navigate to parent node" or checking
* on an element's breadcrumbs.
*
* When moving on to the next node, therefore, if the bottom-most element
* on the stack is a void element, it must be closed.
*
* @todo Once self-closing foreign elements and BGSOUND are supported,
* they must also be implicitly closed here too. BGSOUND is
* special since it's only self-closing if the self-closing flag
* is provided in the opening tag, otherwise it expects a tag closer.
*/
$top_node = $this->state->stack_of_open_elements->current_node();
if (
$top_node && (
// Void elements.
self::is_void( $top_node->node_name ) ||
// Comments, text nodes, and other atomic tokens.
'#' === $top_node->node_name[0] ||
// Doctype declarations.
'html' === $top_node->node_name
)
) {
$this->state->stack_of_open_elements->pop();
}
}
if ( self::PROCESS_NEXT_NODE === $node_to_process ) {
parent::next_token();
}
// Finish stepping when there are no more tokens in the document.
if (
WP_HTML_Tag_Processor::STATE_INCOMPLETE_INPUT === $this->parser_state ||
WP_HTML_Tag_Processor::STATE_COMPLETE === $this->parser_state
) {
return false;
}
$this->state->current_token = new WP_HTML_Token(
$this->bookmark_token(),
$this->get_token_name(),
$this->has_self_closing_flag(),
$this->release_internal_bookmark_on_destruct
);
try {
switch ( $this->state->insertion_mode ) {
case WP_HTML_Processor_State::INSERTION_MODE_IN_BODY:
return $this->step_in_body();
default:
$this->last_error = self::ERROR_UNSUPPORTED;
throw new WP_HTML_Unsupported_Exception( "No support for parsing in the '{$this->state->insertion_mode}' state." );
}
} catch ( WP_HTML_Unsupported_Exception $e ) {
/*
* Exceptions are used in this class to escape deep call stacks that
* otherwise might involve messier calling and return conventions.
*/
return false;
}
}
/**
* Computes the HTML breadcrumbs for the currently-matched node, if matched.
*
* Breadcrumbs start at the outermost parent and descend toward the matched element.
* They always include the entire path from the root HTML node to the matched element.
*
* @todo It could be more efficient to expose a generator-based version of this function
* to avoid creating the array copy on tag iteration. If this is done, it would likely
* be more useful to walk up the stack when yielding instead of starting at the top.
*
* Example
*
* $processor = WP_HTML_Processor::create_fragment( '<p><strong><em><img></em></strong></p>' );
* $processor->next_tag( 'IMG' );
* $processor->get_breadcrumbs() === array( 'HTML', 'BODY', 'P', 'STRONG', 'EM', 'IMG' );
*
* @since 6.4.0
*
* @return string[]|null Array of tag names representing path to matched node, if matched, otherwise NULL.
*/
public function get_breadcrumbs() {
$breadcrumbs = array();
foreach ( $this->state->stack_of_open_elements->walk_down() as $stack_item ) {
$breadcrumbs[] = $stack_item->node_name;
}
return $breadcrumbs;
}
/**
* Parses next element in the 'in body' insertion mode.
*
* This internal function performs the 'in body' insertion mode
* logic for the generalized WP_HTML_Processor::step() function.
*
* @since 6.4.0
*
* @throws WP_HTML_Unsupported_Exception When encountering unsupported HTML input.
*
* @see https://html.spec.whatwg.org/#parsing-main-inbody
* @see WP_HTML_Processor::step
*
* @return bool Whether an element was found.
*/
private function step_in_body() {
$token_name = $this->get_token_name();
$token_type = $this->get_token_type();
$op_sigil = '#tag' === $token_type ? ( $this->is_tag_closer() ? '-' : '+' ) : '';
$op = "{$op_sigil}{$token_name}";
switch ( $op ) {
case '#comment':
case '#funky-comment':
case '#presumptuous-tag':
$this->insert_html_element( $this->state->current_token );
return true;
case '#text':
$this->reconstruct_active_formatting_elements();
$current_token = $this->bookmarks[ $this->state->current_token->bookmark_name ];
/*
* > A character token that is U+0000 NULL
*
* Any successive sequence of NULL bytes is ignored and won't
* trigger active format reconstruction. Therefore, if the text
* only comprises NULL bytes then the token should be ignored
* here, but if there are any other characters in the stream
* the active formats should be reconstructed.
*/
if (
1 <= $current_token->length &&
"\x00" === $this->html[ $current_token->start ] &&
strspn( $this->html, "\x00", $current_token->start, $current_token->length ) === $current_token->length
) {
// Parse error: ignore the token.
return $this->step();
}
/*
* Whitespace-only text does not affect the frameset-ok flag.
* It is probably inter-element whitespace, but it may also
* contain character references which decode only to whitespace.
*/
$text = $this->get_modifiable_text();
if ( strlen( $text ) !== strspn( $text, " \t\n\f\r" ) ) {
$this->state->frameset_ok = false;
}
$this->insert_html_element( $this->state->current_token );
return true;
case 'html':
/*
* > A DOCTYPE token
* > Parse error. Ignore the token.
*/
return $this->step();
/*
* > A start tag whose tag name is "button"
*/
case '+BUTTON':
if ( $this->state->stack_of_open_elements->has_element_in_scope( 'BUTTON' ) ) {
// @todo Indicate a parse error once it's possible. This error does not impact the logic here.
$this->generate_implied_end_tags();
$this->state->stack_of_open_elements->pop_until( 'BUTTON' );
}
$this->reconstruct_active_formatting_elements();
$this->insert_html_element( $this->state->current_token );
$this->state->frameset_ok = false;
return true;
/*
* > A start tag whose tag name is one of: "address", "article", "aside",
* > "blockquote", "center", "details", "dialog", "dir", "div", "dl",
* > "fieldset", "figcaption", "figure", "footer", "header", "hgroup",
* > "main", "menu", "nav", "ol", "p", "search", "section", "summary", "ul"
*/
case '+ADDRESS':
case '+ARTICLE':
case '+ASIDE':
case '+BLOCKQUOTE':
case '+CENTER':
case '+DETAILS':
case '+DIALOG':
case '+DIR':
case '+DIV':
case '+DL':
case '+FIELDSET':
case '+FIGCAPTION':
case '+FIGURE':
case '+FOOTER':
case '+HEADER':
case '+HGROUP':
case '+MAIN':
case '+MENU':
case '+NAV':
case '+OL':
case '+P':
case '+SEARCH':
case '+SECTION':
case '+SUMMARY':
case '+UL':
if ( $this->state->stack_of_open_elements->has_p_in_button_scope() ) {
$this->close_a_p_element();
}
$this->insert_html_element( $this->state->current_token );
return true;
/*
* > An end tag whose tag name is one of: "address", "article", "aside", "blockquote",
* > "button", "center", "details", "dialog", "dir", "div", "dl", "fieldset",
* > "figcaption", "figure", "footer", "header", "hgroup", "listing", "main",
* > "menu", "nav", "ol", "pre", "search", "section", "summary", "ul"
*/
case '-ADDRESS':
case '-ARTICLE':
case '-ASIDE':
case '-BLOCKQUOTE':
case '-BUTTON':
case '-CENTER':
case '-DETAILS':
case '-DIALOG':
case '-DIR':
case '-DIV':
case '-DL':
case '-FIELDSET':
case '-FIGCAPTION':
case '-FIGURE':
case '-FOOTER':
case '-HEADER':
case '-HGROUP':
case '-LISTING':
case '-MAIN':
case '-MENU':
case '-NAV':
case '-OL':
case '-PRE':
case '-SEARCH':
case '-SECTION':
case '-SUMMARY':
case '-UL':
if ( ! $this->state->stack_of_open_elements->has_element_in_scope( $token_name ) ) {
// @todo Report parse error.
// Ignore the token.
return $this->step();
}
$this->generate_implied_end_tags();
if ( $this->state->stack_of_open_elements->current_node()->node_name !== $token_name ) {
// @todo Record parse error: this error doesn't impact parsing.
}
$this->state->stack_of_open_elements->pop_until( $token_name );
return true;
/*
* > A start tag whose tag name is one of: "h1", "h2", "h3", "h4", "h5", "h6"
*/
case '+H1':
case '+H2':
case '+H3':
case '+H4':
case '+H5':
case '+H6':
if ( $this->state->stack_of_open_elements->has_p_in_button_scope() ) {
$this->close_a_p_element();
}
if (
in_array(
$this->state->stack_of_open_elements->current_node()->node_name,
array( 'H1', 'H2', 'H3', 'H4', 'H5', 'H6' ),
true
)
) {
// @todo Indicate a parse error once it's possible.
$this->state->stack_of_open_elements->pop();
}
$this->insert_html_element( $this->state->current_token );
return true;
/*
* > A start tag whose tag name is one of: "pre", "listing"
*/
case '+PRE':
case '+LISTING':
if ( $this->state->stack_of_open_elements->has_p_in_button_scope() ) {
$this->close_a_p_element();
}
$this->insert_html_element( $this->state->current_token );
$this->state->frameset_ok = false;
return true;
/*
* > An end tag whose tag name is one of: "h1", "h2", "h3", "h4", "h5", "h6"
*/
case '-H1':
case '-H2':
case '-H3':
case '-H4':
case '-H5':
case '-H6':
if ( ! $this->state->stack_of_open_elements->has_element_in_scope( '(internal: H1 through H6 - do not use)' ) ) {
/*
* This is a parse error; ignore the token.
*
* @todo Indicate a parse error once it's possible.
*/
return $this->step();
}
$this->generate_implied_end_tags();
if ( $this->state->stack_of_open_elements->current_node()->node_name !== $token_name ) {
// @todo Record parse error: this error doesn't impact parsing.
}
$this->state->stack_of_open_elements->pop_until( '(internal: H1 through H6 - do not use)' );
return true;
/*
* > A start tag whose tag name is "li"
* > A start tag whose tag name is one of: "dd", "dt"
*/
case '+DD':
case '+DT':
case '+LI':
$this->state->frameset_ok = false;
$node = $this->state->stack_of_open_elements->current_node();
$is_li = 'LI' === $token_name;
in_body_list_loop:
/*
* The logic for LI and DT/DD is the same except for one point: LI elements _only_
* close other LI elements, but a DT or DD element closes _any_ open DT or DD element.
*/
if ( $is_li ? 'LI' === $node->node_name : ( 'DD' === $node->node_name || 'DT' === $node->node_name ) ) {
$node_name = $is_li ? 'LI' : $node->node_name;
$this->generate_implied_end_tags( $node_name );
if ( $node_name !== $this->state->stack_of_open_elements->current_node()->node_name ) {
// @todo Indicate a parse error once it's possible. This error does not impact the logic here.
}
$this->state->stack_of_open_elements->pop_until( $node_name );
goto in_body_list_done;
}
if (
'ADDRESS' !== $node->node_name &&
'DIV' !== $node->node_name &&
'P' !== $node->node_name &&
$this->is_special( $node->node_name )
) {
/*
* > If node is in the special category, but is not an address, div,
* > or p element, then jump to the step labeled done below.
*/
goto in_body_list_done;
} else {
/*
* > Otherwise, set node to the previous entry in the stack of open elements
* > and return to the step labeled loop.
*/
foreach ( $this->state->stack_of_open_elements->walk_up( $node ) as $item ) {
$node = $item;
break;
}
goto in_body_list_loop;
}
in_body_list_done:
if ( $this->state->stack_of_open_elements->has_p_in_button_scope() ) {
$this->close_a_p_element();
}
$this->insert_html_element( $this->state->current_token );
return true;
/*
* > An end tag whose tag name is "li"
* > An end tag whose tag name is one of: "dd", "dt"
*/
case '-DD':
case '-DT':
case '-LI':
if (
/*
* An end tag whose tag name is "li":
* If the stack of open elements does not have an li element in list item scope,
* then this is a parse error; ignore the token.
*/
(
'LI' === $token_name &&
! $this->state->stack_of_open_elements->has_element_in_list_item_scope( 'LI' )
) ||
/*
* An end tag whose tag name is one of: "dd", "dt":
* If the stack of open elements does not have an element in scope that is an
* HTML element with the same tag name as that of the token, then this is a
* parse error; ignore the token.
*/
(
'LI' !== $token_name &&
! $this->state->stack_of_open_elements->has_element_in_scope( $token_name )
)
) {
/*
* This is a parse error, ignore the token.
*
* @todo Indicate a parse error once it's possible.
*/
return $this->step();
}
$this->generate_implied_end_tags( $token_name );
if ( $token_name !== $this->state->stack_of_open_elements->current_node()->node_name ) {
// @todo Indicate a parse error once it's possible. This error does not impact the logic here.
}
$this->state->stack_of_open_elements->pop_until( $token_name );
return true;
/*
* > An end tag whose tag name is "p"
*/
case '-P':
if ( ! $this->state->stack_of_open_elements->has_p_in_button_scope() ) {
$this->insert_html_element( $this->state->current_token );
}
$this->close_a_p_element();
return true;
// > A start tag whose tag name is "a"
case '+A':
foreach ( $this->state->active_formatting_elements->walk_up() as $item ) {
switch ( $item->node_name ) {
case 'marker':
break;
case 'A':
$this->run_adoption_agency_algorithm();
$this->state->active_formatting_elements->remove_node( $item );
$this->state->stack_of_open_elements->remove_node( $item );
break;
}
}
$this->reconstruct_active_formatting_elements();
$this->insert_html_element( $this->state->current_token );
$this->state->active_formatting_elements->push( $this->state->current_token );
return true;
/*
* > A start tag whose tag name is one of: "b", "big", "code", "em", "font", "i",
* > "s", "small", "strike", "strong", "tt", "u"
*/
case '+B':
case '+BIG':
case '+CODE':
case '+EM':
case '+FONT':
case '+I':
case '+S':
case '+SMALL':
case '+STRIKE':
case '+STRONG':
case '+TT':
case '+U':
$this->reconstruct_active_formatting_elements();
$this->insert_html_element( $this->state->current_token );
$this->state->active_formatting_elements->push( $this->state->current_token );
return true;
/*
* > An end tag whose tag name is one of: "a", "b", "big", "code", "em", "font", "i",
* > "nobr", "s", "small", "strike", "strong", "tt", "u"
*/
case '-A':
case '-B':
case '-BIG':
case '-CODE':
case '-EM':
case '-FONT':
case '-I':
case '-S':
case '-SMALL':
case '-STRIKE':
case '-STRONG':
case '-TT':
case '-U':
$this->run_adoption_agency_algorithm();
return true;
/*
* > An end tag whose tag name is "br"
* > Parse error. Drop the attributes from the token, and act as described in the next
* > entry; i.e. act as if this was a "br" start tag token with no attributes, rather
* > than the end tag token that it actually is.
*/
case '-BR':
$this->last_error = self::ERROR_UNSUPPORTED;
throw new WP_HTML_Unsupported_Exception( 'Closing BR tags require unimplemented special handling.' );
/*
* > A start tag whose tag name is one of: "area", "br", "embed", "img", "keygen", "wbr"
*/
case '+AREA':
case '+BR':
case '+EMBED':
case '+IMG':
case '+KEYGEN':
case '+WBR':
$this->reconstruct_active_formatting_elements();
$this->insert_html_element( $this->state->current_token );
$this->state->frameset_ok = false;
return true;
/*
* > A start tag whose tag name is "input"
*/
case '+INPUT':
$this->reconstruct_active_formatting_elements();
$this->insert_html_element( $this->state->current_token );
$type_attribute = $this->get_attribute( 'type' );
/*
* > If the token does not have an attribute with the name "type", or if it does,
* > but that attribute's value is not an ASCII case-insensitive match for the
* > string "hidden", then: set the frameset-ok flag to "not ok".
*/
if ( ! is_string( $type_attribute ) || 'hidden' !== strtolower( $type_attribute ) ) {
$this->state->frameset_ok = false;
}
return true;
/*
* > A start tag whose tag name is "hr"
*/
case '+HR':
if ( $this->state->stack_of_open_elements->has_p_in_button_scope() ) {
$this->close_a_p_element();
}
$this->insert_html_element( $this->state->current_token );
$this->state->frameset_ok = false;
return true;
/*
* > A start tag whose tag name is one of: "param", "source", "track"
*/
case '+PARAM':
case '+SOURCE':
case '+TRACK':
$this->insert_html_element( $this->state->current_token );
return true;
}
/*
* These tags require special handling in the 'in body' insertion mode
* but that handling hasn't yet been implemented.
*
* As the rules for each tag are implemented, the corresponding tag
* name should be removed from this list. An accompanying test should
* help ensure this list is maintained.
*
* @see Tests_HtmlApi_WpHtmlProcessor::test_step_in_body_fails_on_unsupported_tags
*
* Since this switch structure throws a WP_HTML_Unsupported_Exception, it's
* possible to handle "any other start tag" and "any other end tag" below,
* as that guarantees execution doesn't proceed for the unimplemented tags.
*
* @see https://html.spec.whatwg.org/multipage/parsing.html#parsing-main-inbody
*/
switch ( $token_name ) {
case 'APPLET':
case 'BASE':
case 'BASEFONT':
case 'BGSOUND':
case 'BODY':
case 'CAPTION':
case 'COL':
case 'COLGROUP':
case 'FORM':
case 'FRAME':
case 'FRAMESET':
case 'HEAD':
case 'HTML':
case 'IFRAME':
case 'LINK':
case 'MARQUEE':
case 'MATH':
case 'META':
case 'NOBR':
case 'NOEMBED':
case 'NOFRAMES':
case 'NOSCRIPT':
case 'OBJECT':
case 'OPTGROUP':
case 'OPTION':
case 'PLAINTEXT':
case 'RB':
case 'RP':
case 'RT':
case 'RTC':
case 'SARCASM':
case 'SCRIPT':
case 'SELECT':
case 'STYLE':
case 'SVG':
case 'TABLE':
case 'TBODY':
case 'TD':
case 'TEMPLATE':
case 'TEXTAREA':
case 'TFOOT':
case 'TH':
case 'THEAD':
case 'TITLE':
case 'TR':
case 'XMP':
$this->last_error = self::ERROR_UNSUPPORTED;
throw new WP_HTML_Unsupported_Exception( "Cannot process {$token_name} element." );
}
if ( ! $this->is_tag_closer() ) {
/*
* > Any other start tag
*/
$this->reconstruct_active_formatting_elements();
$this->insert_html_element( $this->state->current_token );
return true;
} else {
/*
* > Any other end tag
*/
/*
* Find the corresponding tag opener in the stack of open elements, if
* it exists before reaching a special element, which provides a kind
* of boundary in the stack. For example, a `</custom-tag>` should not
* close anything beyond its containing `P` or `DIV` element.
*/
foreach ( $this->state->stack_of_open_elements->walk_up() as $node ) {
if ( $token_name === $node->node_name ) {
break;
}
if ( self::is_special( $node->node_name ) ) {
// This is a parse error, ignore the token.
return $this->step();
}
}
$this->generate_implied_end_tags( $token_name );
if ( $node !== $this->state->stack_of_open_elements->current_node() ) {
// @todo Record parse error: this error doesn't impact parsing.
}
foreach ( $this->state->stack_of_open_elements->walk_up() as $item ) {
$this->state->stack_of_open_elements->pop();
if ( $node === $item ) {
return true;
}
}
}
}
/*
* Internal helpers
*/
/**
* Creates a new bookmark for the currently-matched token and returns the generated name.
*
* @since 6.4.0
* @since 6.5.0 Renamed from bookmark_tag() to bookmark_token().
*
* @throws Exception When unable to allocate requested bookmark.
*
* @return string|false Name of created bookmark, or false if unable to create.
*/
private function bookmark_token() {
if ( ! parent::set_bookmark( ++$this->bookmark_counter ) ) {
$this->last_error = self::ERROR_EXCEEDED_MAX_BOOKMARKS;
throw new Exception( 'could not allocate bookmark' );
}
return "{$this->bookmark_counter}";
}
/*
* HTML semantic overrides for Tag Processor
*/
/**
* Returns the uppercase name of the matched tag.
*
* The semantic rules for HTML specify that certain tags be reprocessed
* with a different tag name. Because of this, the tag name presented
* by the HTML Processor may differ from the one reported by the HTML
* Tag Processor, which doesn't apply these semantic rules.
*
* Example:
*
* $processor = new WP_HTML_Tag_Processor( '<div class="test">Test</div>' );
* $processor->next_tag() === true;
* $processor->get_tag() === 'DIV';
*
* $processor->next_tag() === false;
* $processor->get_tag() === null;
*
* @since 6.4.0
*
* @return string|null Name of currently matched tag in input HTML, or `null` if none found.
*/
public function get_tag() {
if ( null !== $this->last_error ) {
return null;
}
$tag_name = parent::get_tag();
switch ( $tag_name ) {
case 'IMAGE':
/*
* > A start tag whose tag name is "image"
* > Change the token's tag name to "img" and reprocess it. (Don't ask.)
*/
return 'IMG';
default:
return $tag_name;
}
}
/**
* Removes a bookmark that is no longer needed.
*
* Releasing a bookmark frees up the small
* performance overhead it requires.
*
* @since 6.4.0
*
* @param string $bookmark_name Name of the bookmark to remove.
* @return bool Whether the bookmark already existed before removal.
*/
public function release_bookmark( $bookmark_name ) {
return parent::release_bookmark( "_{$bookmark_name}" );
}
/**
* Moves the internal cursor in the HTML Processor to a given bookmark's location.
*
* Be careful! Seeking backwards to a previous location resets the parser to the
* start of the document and reparses the entire contents up until it finds the
* sought-after bookmarked location.
*
* In order to prevent accidental infinite loops, there's a
* maximum limit on the number of times seek() can be called.
*
* @throws Exception When unable to allocate a bookmark for the next token in the input HTML document.
*
* @since 6.4.0
*
* @param string $bookmark_name Jump to the place in the document identified by this bookmark name.
* @return bool Whether the internal cursor was successfully moved to the bookmark's location.
*/
public function seek( $bookmark_name ) {
// Flush any pending updates to the document before beginning.
$this->get_updated_html();
$actual_bookmark_name = "_{$bookmark_name}";
$processor_started_at = $this->state->current_token
? $this->bookmarks[ $this->state->current_token->bookmark_name ]->start
: 0;
$bookmark_starts_at = $this->bookmarks[ $actual_bookmark_name ]->start;
$direction = $bookmark_starts_at > $processor_started_at ? 'forward' : 'backward';
/*
* If seeking backwards, it's possible that the sought-after bookmark exists within an element
* which has been closed before the current cursor; in other words, it has already been removed
* from the stack of open elements. This means that it's insufficient to simply pop off elements
* from the stack of open elements which appear after the bookmarked location and then jump to
* that location, as the elements which were open before won't be re-opened.
*
* In order to maintain consistency, the HTML Processor rewinds to the start of the document
* and reparses everything until it finds the sought-after bookmark.
*
* There are potentially better ways to do this: cache the parser state for each bookmark and
* restore it when seeking; store an immutable and idempotent register of where elements open
* and close.
*
* If caching the parser state it will be essential to properly maintain the cached stack of
* open elements and active formatting elements when modifying the document. This could be a
* tedious and time-consuming process as well, and so for now will not be performed.
*
* It may be possible to track bookmarks for where elements open and close, and in doing so
* be able to quickly recalculate breadcrumbs for any element in the document. It may even
* be possible to remove the stack of open elements and compute it on the fly this way.
* If doing this, the parser would need to track the opening and closing locations for all
* tokens in the breadcrumb path for any and all bookmarks. By utilizing bookmarks themselves
* this list could be automatically maintained while modifying the document. Finding the
* breadcrumbs would then amount to traversing that list from the start until the token
* being inspected. Once an element closes, if there are no bookmarks pointing to locations
* within that element, then all of these locations may be forgotten to save on memory use
* and computation time.
*/
if ( 'backward' === $direction ) {
/*
* Instead of clearing the parser state and starting fresh, calling the stack methods
* maintains the proper flags in the parser.
*/
foreach ( $this->state->stack_of_open_elements->walk_up() as $item ) {
if ( 'context-node' === $item->bookmark_name ) {
break;
}
$this->state->stack_of_open_elements->remove_node( $item );
}
foreach ( $this->state->active_formatting_elements->walk_up() as $item ) {
if ( 'context-node' === $item->bookmark_name ) {
break;
}
$this->state->active_formatting_elements->remove_node( $item );
}
parent::seek( 'context-node' );
$this->state->insertion_mode = WP_HTML_Processor_State::INSERTION_MODE_IN_BODY;
$this->state->frameset_ok = true;
}
// When moving forwards, reparse the document until reaching the same location as the original bookmark.
if ( $bookmark_starts_at === $this->bookmarks[ $this->state->current_token->bookmark_name ]->start ) {
return true;
}
while ( $this->step() ) {
if ( $bookmark_starts_at === $this->bookmarks[ $this->state->current_token->bookmark_name ]->start ) {
return true;
}
}
return false;
}
/**
* Sets a bookmark in the HTML document.
*
* Bookmarks represent specific places or tokens in the HTML
* document, such as a tag opener or closer. When applying
* edits to a document, such as setting an attribute, the
* text offsets of that token may shift; the bookmark is
* kept updated with those shifts and remains stable unless
* the entire span of text in which the token sits is removed.
*
* Release bookmarks when they are no longer needed.
*
* Example:
*
* <main><h2>Surprising fact you may not know!</h2></main>
* ^ ^
* \-|-- this `H2` opener bookmark tracks the token
*
* <main class="clickbait"><h2>Surprising fact you may no…
* ^ ^
* \-|-- it shifts with edits
*
* Bookmarks provide the ability to seek to a previously-scanned
* place in the HTML document. This avoids the need to re-scan
* the entire document.
*
* Example:
*
* <ul><li>One</li><li>Two</li><li>Three</li></ul>
* ^^^^
* want to note this last item
*
* $p = new WP_HTML_Tag_Processor( $html );
* $in_list = false;
* while ( $p->next_tag( array( 'tag_closers' => $in_list ? 'visit' : 'skip' ) ) ) {
* if ( 'UL' === $p->get_tag() ) {
* if ( $p->is_tag_closer() ) {
* $in_list = false;
* $p->set_bookmark( 'resume' );
* if ( $p->seek( 'last-li' ) ) {
* $p->add_class( 'last-li' );
* }
* $p->seek( 'resume' );
* $p->release_bookmark( 'last-li' );
* $p->release_bookmark( 'resume' );
* } else {
* $in_list = true;
* }
* }
*
* if ( 'LI' === $p->get_tag() ) {
* $p->set_bookmark( 'last-li' );
* }
* }
*
* Bookmarks intentionally hide the internal string offsets
* to which they refer. They are maintained internally as
* updates are applied to the HTML document and therefore
* retain their "position" - the location to which they
* originally pointed. The inability to use bookmarks with
* functions like `substr` is therefore intentional to guard
* against accidentally breaking the HTML.
*
* Because bookmarks allocate memory and require processing
* for every applied update, they are limited and require
* a name. They should not be created with programmatically-made
* names, such as "li_{$index}" with some loop. As a general
* rule they should only be created with string-literal names
* like "start-of-section" or "last-paragraph".
*
* Bookmarks are a powerful tool to enable complicated behavior.
* Consider double-checking that you need this tool if you are
* reaching for it, as inappropriate use could lead to broken
* HTML structure or unwanted processing overhead.
*
* @since 6.4.0
*
* @param string $bookmark_name Identifies this particular bookmark.
* @return bool Whether the bookmark was successfully created.
*/
public function set_bookmark( $bookmark_name ) {
return parent::set_bookmark( "_{$bookmark_name}" );
}
/**
* Checks whether a bookmark with the given name exists.
*
* @since 6.5.0
*
* @param string $bookmark_name Name to identify a bookmark that potentially exists.
* @return bool Whether that bookmark exists.
*/
public function has_bookmark( $bookmark_name ) {
return parent::has_bookmark( "_{$bookmark_name}" );
}
/*
* HTML Parsing Algorithms
*/
/**
* Closes a P element.
*
* @since 6.4.0
*
* @throws WP_HTML_Unsupported_Exception When encountering unsupported HTML input.
*
* @see https://html.spec.whatwg.org/#close-a-p-element
*/
private function close_a_p_element() {
$this->generate_implied_end_tags( 'P' );
$this->state->stack_of_open_elements->pop_until( 'P' );
}
/**
* Closes elements that have implied end tags.
*
* @since 6.4.0
*
* @see https://html.spec.whatwg.org/#generate-implied-end-tags
*
* @param string|null $except_for_this_element Perform as if this element doesn't exist in the stack of open elements.
*/
private function generate_implied_end_tags( $except_for_this_element = null ) {
$elements_with_implied_end_tags = array(
'DD',
'DT',
'LI',
'P',
);
$current_node = $this->state->stack_of_open_elements->current_node();
while (
$current_node && $current_node->node_name !== $except_for_this_element &&
in_array( $this->state->stack_of_open_elements->current_node(), $elements_with_implied_end_tags, true )
) {
$this->state->stack_of_open_elements->pop();
}
}
/**
* Closes elements that have implied end tags, thoroughly.
*
* See the HTML specification for an explanation why this is
* different from generating end tags in the normal sense.
*
* @since 6.4.0
*
* @see WP_HTML_Processor::generate_implied_end_tags
* @see https://html.spec.whatwg.org/#generate-implied-end-tags
*/
private function generate_implied_end_tags_thoroughly() {
$elements_with_implied_end_tags = array(
'DD',
'DT',
'LI',
'P',
);
while ( in_array( $this->state->stack_of_open_elements->current_node(), $elements_with_implied_end_tags, true ) ) {
$this->state->stack_of_open_elements->pop();
}
}
/**
* Reconstructs the active formatting elements.
*
* > This has the effect of reopening all the formatting elements that were opened
* > in the current body, cell, or caption (whichever is youngest) that haven't
* > been explicitly closed.
*
* @since 6.4.0
*
* @throws WP_HTML_Unsupported_Exception When encountering unsupported HTML input.
*
* @see https://html.spec.whatwg.org/#reconstruct-the-active-formatting-elements
*
* @return bool Whether any formatting elements needed to be reconstructed.
*/
private function reconstruct_active_formatting_elements() {
/*
* > If there are no entries in the list of active formatting elements, then there is nothing
* > to reconstruct; stop this algorithm.
*/
if ( 0 === $this->state->active_formatting_elements->count() ) {
return false;
}
$last_entry = $this->state->active_formatting_elements->current_node();
if (
/*
* > If the last (most recently added) entry in the list of active formatting elements is a marker;
* > stop this algorithm.
*/
'marker' === $last_entry->node_name ||
/*
* > If the last (most recently added) entry in the list of active formatting elements is an
* > element that is in the stack of open elements, then there is nothing to reconstruct;
* > stop this algorithm.
*/
$this->state->stack_of_open_elements->contains_node( $last_entry )
) {
return false;
}
$this->last_error = self::ERROR_UNSUPPORTED;
throw new WP_HTML_Unsupported_Exception( 'Cannot reconstruct active formatting elements when advancing and rewinding is required.' );
}
/**
* Runs the adoption agency algorithm.
*
* @since 6.4.0
*
* @throws WP_HTML_Unsupported_Exception When encountering unsupported HTML input.
*
* @see https://html.spec.whatwg.org/#adoption-agency-algorithm
*/
private function run_adoption_agency_algorithm() {
$budget = 1000;
$subject = $this->get_tag();
$current_node = $this->state->stack_of_open_elements->current_node();
if (
// > If the current node is an HTML element whose tag name is subject
$current_node && $subject === $current_node->node_name &&
// > the current node is not in the list of active formatting elements
! $this->state->active_formatting_elements->contains_node( $current_node )
) {
$this->state->stack_of_open_elements->pop();
return;
}
$outer_loop_counter = 0;
while ( $budget-- > 0 ) {
if ( $outer_loop_counter++ >= 8 ) {
return;
}
/*
* > Let formatting element be the last element in the list of active formatting elements that:
* > - is between the end of the list and the last marker in the list,
* > if any, or the start of the list otherwise,
* > - and has the tag name subject.
*/
$formatting_element = null;
foreach ( $this->state->active_formatting_elements->walk_up() as $item ) {
if ( 'marker' === $item->node_name ) {
break;
}
if ( $subject === $item->node_name ) {
$formatting_element = $item;
break;
}
}
// > If there is no such element, then return and instead act as described in the "any other end tag" entry above.
if ( null === $formatting_element ) {
$this->last_error = self::ERROR_UNSUPPORTED;
throw new WP_HTML_Unsupported_Exception( 'Cannot run adoption agency when "any other end tag" is required.' );
}
// > If formatting element is not in the stack of open elements, then this is a parse error; remove the element from the list, and return.
if ( ! $this->state->stack_of_open_elements->contains_node( $formatting_element ) ) {
$this->state->active_formatting_elements->remove_node( $formatting_element );
return;
}
// > If formatting element is in the stack of open elements, but the element is not in scope, then this is a parse error; return.
if ( ! $this->state->stack_of_open_elements->has_element_in_scope( $formatting_element->node_name ) ) {
return;
}
/*
* > Let furthest block be the topmost node in the stack of open elements that is lower in the stack
* > than formatting element, and is an element in the special category. There might not be one.
*/
$is_above_formatting_element = true;
$furthest_block = null;
foreach ( $this->state->stack_of_open_elements->walk_down() as $item ) {
if ( $is_above_formatting_element && $formatting_element->bookmark_name !== $item->bookmark_name ) {
continue;
}
if ( $is_above_formatting_element ) {
$is_above_formatting_element = false;
continue;
}
if ( self::is_special( $item->node_name ) ) {
$furthest_block = $item;
break;
}
}
/*
* > If there is no furthest block, then the UA must first pop all the nodes from the bottom of the
* > stack of open elements, from the current node up to and including formatting element, then
* > remove formatting element from the list of active formatting elements, and finally return.
*/
if ( null === $furthest_block ) {
foreach ( $this->state->stack_of_open_elements->walk_up() as $item ) {
$this->state->stack_of_open_elements->pop();
if ( $formatting_element->bookmark_name === $item->bookmark_name ) {
$this->state->active_formatting_elements->remove_node( $formatting_element );
return;
}
}
}
$this->last_error = self::ERROR_UNSUPPORTED;
throw new WP_HTML_Unsupported_Exception( 'Cannot extract common ancestor in adoption agency algorithm.' );
}
$this->last_error = self::ERROR_UNSUPPORTED;
throw new WP_HTML_Unsupported_Exception( 'Cannot run adoption agency when looping required.' );
}
/**
* Inserts an HTML element on the stack of open elements.
*
* @since 6.4.0
*
* @see https://html.spec.whatwg.org/#insert-a-foreign-element
*
* @param WP_HTML_Token $token Name of bookmark pointing to element in original input HTML.
*/
private function insert_html_element( $token ) {
$this->state->stack_of_open_elements->push( $token );
}
/*
* HTML Specification Helpers
*/
/**
* Returns whether an element of a given name is in the HTML special category.
*
* @since 6.4.0
*
* @see https://html.spec.whatwg.org/#special
*
* @param string $tag_name Name of element to check.
* @return bool Whether the element of the given name is in the special category.
*/
public static function is_special( $tag_name ) {
$tag_name = strtoupper( $tag_name );
return (
'ADDRESS' === $tag_name ||
'APPLET' === $tag_name ||
'AREA' === $tag_name ||
'ARTICLE' === $tag_name ||
'ASIDE' === $tag_name ||
'BASE' === $tag_name ||
'BASEFONT' === $tag_name ||
'BGSOUND' === $tag_name ||
'BLOCKQUOTE' === $tag_name ||
'BODY' === $tag_name ||
'BR' === $tag_name ||
'BUTTON' === $tag_name ||
'CAPTION' === $tag_name ||
'CENTER' === $tag_name ||
'COL' === $tag_name ||
'COLGROUP' === $tag_name ||
'DD' === $tag_name ||
'DETAILS' === $tag_name ||
'DIR' === $tag_name ||
'DIV' === $tag_name ||
'DL' === $tag_name ||
'DT' === $tag_name ||
'EMBED' === $tag_name ||
'FIELDSET' === $tag_name ||
'FIGCAPTION' === $tag_name ||
'FIGURE' === $tag_name ||
'FOOTER' === $tag_name ||
'FORM' === $tag_name ||
'FRAME' === $tag_name ||
'FRAMESET' === $tag_name ||
'H1' === $tag_name ||
'H2' === $tag_name ||
'H3' === $tag_name ||
'H4' === $tag_name ||
'H5' === $tag_name ||
'H6' === $tag_name ||
'HEAD' === $tag_name ||
'HEADER' === $tag_name ||
'HGROUP' === $tag_name ||
'HR' === $tag_name ||
'HTML' === $tag_name ||
'IFRAME' === $tag_name ||
'IMG' === $tag_name ||
'INPUT' === $tag_name ||
'KEYGEN' === $tag_name ||
'LI' === $tag_name ||
'LINK' === $tag_name ||
'LISTING' === $tag_name ||
'MAIN' === $tag_name ||
'MARQUEE' === $tag_name ||
'MENU' === $tag_name ||
'META' === $tag_name ||
'NAV' === $tag_name ||
'NOEMBED' === $tag_name ||
'NOFRAMES' === $tag_name ||
'NOSCRIPT' === $tag_name ||
'OBJECT' === $tag_name ||
'OL' === $tag_name ||
'P' === $tag_name ||
'PARAM' === $tag_name ||
'PLAINTEXT' === $tag_name ||
'PRE' === $tag_name ||
'SCRIPT' === $tag_name ||
'SEARCH' === $tag_name ||
'SECTION' === $tag_name ||
'SELECT' === $tag_name ||
'SOURCE' === $tag_name ||
'STYLE' === $tag_name ||
'SUMMARY' === $tag_name ||
'TABLE' === $tag_name ||
'TBODY' === $tag_name ||
'TD' === $tag_name ||
'TEMPLATE' === $tag_name ||
'TEXTAREA' === $tag_name ||
'TFOOT' === $tag_name ||
'TH' === $tag_name ||
'THEAD' === $tag_name ||
'TITLE' === $tag_name ||
'TR' === $tag_name ||
'TRACK' === $tag_name ||
'UL' === $tag_name ||
'WBR' === $tag_name ||
'XMP' === $tag_name ||
// MathML.
'MI' === $tag_name ||
'MO' === $tag_name ||
'MN' === $tag_name ||
'MS' === $tag_name ||
'MTEXT' === $tag_name ||
'ANNOTATION-XML' === $tag_name ||
// SVG.
'FOREIGNOBJECT' === $tag_name ||
'DESC' === $tag_name ||
'TITLE' === $tag_name
);
}
/**
* Returns whether a given element is an HTML Void Element
*
* > area, base, br, col, embed, hr, img, input, link, meta, source, track, wbr
*
* @since 6.4.0
*
* @see https://html.spec.whatwg.org/#void-elements
*
* @param string $tag_name Name of HTML tag to check.
* @return bool Whether the given tag is an HTML Void Element.
*/
public static function is_void( $tag_name ) {
$tag_name = strtoupper( $tag_name );
return (
'AREA' === $tag_name ||
'BASE' === $tag_name ||
'BASEFONT' === $tag_name || // Obsolete but still treated as void.
'BGSOUND' === $tag_name || // Obsolete but still treated as void.
'BR' === $tag_name ||
'COL' === $tag_name ||
'EMBED' === $tag_name ||
'FRAME' === $tag_name ||
'HR' === $tag_name ||
'IMG' === $tag_name ||
'INPUT' === $tag_name ||
'KEYGEN' === $tag_name || // Obsolete but still treated as void.
'LINK' === $tag_name ||
'META' === $tag_name ||
'PARAM' === $tag_name || // Obsolete but still treated as void.
'SOURCE' === $tag_name ||
'TRACK' === $tag_name ||
'WBR' === $tag_name
);
}
/*
* Constants that would pollute the top of the class if they were found there.
*/
/**
* Indicates that the next HTML token should be parsed and processed.
*
* @since 6.4.0
*
* @var string
*/
const PROCESS_NEXT_NODE = 'process-next-node';
/**
* Indicates that the current HTML token should be reprocessed in the newly-selected insertion mode.
*
* @since 6.4.0
*
* @var string
*/
const REPROCESS_CURRENT_NODE = 'reprocess-current-node';
/**
* Indicates that the current HTML token should be processed without advancing the parser.
*
* @since 6.5.0
*
* @var string
*/
const PROCESS_CURRENT_NODE = 'process-current-node';
/**
* Indicates that the parser encountered unsupported markup and has bailed.
*
* @since 6.4.0
*
* @var string
*/
const ERROR_UNSUPPORTED = 'unsupported';
/**
* Indicates that the parser encountered more HTML tokens than it
* was able to process and has bailed.
*
* @since 6.4.0
*
* @var string
*/
const ERROR_EXCEEDED_MAX_BOOKMARKS = 'exceeded-max-bookmarks';
/**
* Unlock code that must be passed into the constructor to create this class.
*
* This class extends the WP_HTML_Tag_Processor, which has a public class
* constructor. Therefore, it's not possible to have a private constructor here.
*
* This unlock code is used to ensure that anyone calling the constructor is
* doing so with a full understanding that it's intended to be a private API.
*
* @access private
*/
const CONSTRUCTOR_UNLOCK_CODE = 'Use WP_HTML_Processor::create_fragment() instead of calling the class constructor directly.';
}
class-wp-html-span.php 0000644 00000002103 15153115200 0010674 0 ustar 00 <?php
/**
* HTML API: WP_HTML_Span class
*
* @package WordPress
* @subpackage HTML-API
* @since 6.2.0
*/
/**
* Core class used by the HTML tag processor to represent a textual span
* inside an HTML document.
*
* This is a two-tuple in disguise, used to avoid the memory overhead
* involved in using an array for the same purpose.
*
* This class is for internal usage of the WP_HTML_Tag_Processor class.
*
* @access private
* @since 6.2.0
* @since 6.5.0 Replaced `end` with `length` to more closely align with `substr()`.
*
* @see WP_HTML_Tag_Processor
*/
class WP_HTML_Span {
/**
* Byte offset into document where span begins.
*
* @since 6.2.0
*
* @var int
*/
public $start;
/**
* Byte length of this span.
*
* @since 6.5.0
*
* @var int
*/
public $length;
/**
* Constructor.
*
* @since 6.2.0
*
* @param int $start Byte offset into document where replacement span begins.
* @param int $length Byte length of span.
*/
public function __construct( $start, $length ) {
$this->start = $start;
$this->length = $length;
}
}
class-wp-html-tag-processor.php 0000644 00000346446 15153115200 0012550 0 ustar 00 <?php
/**
* HTML API: WP_HTML_Tag_Processor class
*
* Scans through an HTML document to find specific tags, then
* transforms those tags by adding, removing, or updating the
* values of the HTML attributes within that tag (opener).
*
* Does not fully parse HTML or _recurse_ into the HTML structure
* Instead this scans linearly through a document and only parses
* the HTML tag openers.
*
* ### Possible future direction for this module
*
* - Prune the whitespace when removing classes/attributes: e.g. "a b c" -> "c" not " c".
* This would increase the size of the changes for some operations but leave more
* natural-looking output HTML.
* - Properly decode HTML character references in `get_attribute()`. PHP's
* `html_entity_decode()` is wrong in a couple ways: it doesn't account for the
* no-ambiguous-ampersand rule, and it improperly handles the way semicolons may
* or may not terminate a character reference.
*
* @package WordPress
* @subpackage HTML-API
* @since 6.2.0
*/
/**
* Core class used to modify attributes in an HTML document for tags matching a query.
*
* ## Usage
*
* Use of this class requires three steps:
*
* 1. Create a new class instance with your input HTML document.
* 2. Find the tag(s) you are looking for.
* 3. Request changes to the attributes in those tag(s).
*
* Example:
*
* $tags = new WP_HTML_Tag_Processor( $html );
* if ( $tags->next_tag( 'option' ) ) {
* $tags->set_attribute( 'selected', true );
* }
*
* ### Finding tags
*
* The `next_tag()` function moves the internal cursor through
* your input HTML document until it finds a tag meeting any of
* the supplied restrictions in the optional query argument. If
* no argument is provided then it will find the next HTML tag,
* regardless of what kind it is.
*
* If you want to _find whatever the next tag is_:
*
* $tags->next_tag();
*
* | Goal | Query |
* |-----------------------------------------------------------|---------------------------------------------------------------------------------|
* | Find any tag. | `$tags->next_tag();` |
* | Find next image tag. | `$tags->next_tag( array( 'tag_name' => 'img' ) );` |
* | Find next image tag (without passing the array). | `$tags->next_tag( 'img' );` |
* | Find next tag containing the `fullwidth` CSS class. | `$tags->next_tag( array( 'class_name' => 'fullwidth' ) );` |
* | Find next image tag containing the `fullwidth` CSS class. | `$tags->next_tag( array( 'tag_name' => 'img', 'class_name' => 'fullwidth' ) );` |
*
* If a tag was found meeting your criteria then `next_tag()`
* will return `true` and you can proceed to modify it. If it
* returns `false`, however, it failed to find the tag and
* moved the cursor to the end of the file.
*
* Once the cursor reaches the end of the file the processor
* is done and if you want to reach an earlier tag you will
* need to recreate the processor and start over, as it's
* unable to back up or move in reverse.
*
* See the section on bookmarks for an exception to this
* no-backing-up rule.
*
* #### Custom queries
*
* Sometimes it's necessary to further inspect an HTML tag than
* the query syntax here permits. In these cases one may further
* inspect the search results using the read-only functions
* provided by the processor or external state or variables.
*
* Example:
*
* // Paint up to the first five DIV or SPAN tags marked with the "jazzy" style.
* $remaining_count = 5;
* while ( $remaining_count > 0 && $tags->next_tag() ) {
* if (
* ( 'DIV' === $tags->get_tag() || 'SPAN' === $tags->get_tag() ) &&
* 'jazzy' === $tags->get_attribute( 'data-style' )
* ) {
* $tags->add_class( 'theme-style-everest-jazz' );
* $remaining_count--;
* }
* }
*
* `get_attribute()` will return `null` if the attribute wasn't present
* on the tag when it was called. It may return `""` (the empty string)
* in cases where the attribute was present but its value was empty.
* For boolean attributes, those whose name is present but no value is
* given, it will return `true` (the only way to set `false` for an
* attribute is to remove it).
*
* #### When matching fails
*
* When `next_tag()` returns `false` it could mean different things:
*
* - The requested tag wasn't found in the input document.
* - The input document ended in the middle of an HTML syntax element.
*
* When a document ends in the middle of a syntax element it will pause
* the processor. This is to make it possible in the future to extend the
* input document and proceed - an important requirement for chunked
* streaming parsing of a document.
*
* Example:
*
* $processor = new WP_HTML_Tag_Processor( 'This <div is="a" partial="token' );
* false === $processor->next_tag();
*
* If a special element (see next section) is encountered but no closing tag
* is found it will count as an incomplete tag. The parser will pause as if
* the opening tag were incomplete.
*
* Example:
*
* $processor = new WP_HTML_Tag_Processor( '<style>// there could be more styling to come' );
* false === $processor->next_tag();
*
* $processor = new WP_HTML_Tag_Processor( '<style>// this is everything</style><div>' );
* true === $processor->next_tag( 'DIV' );
*
* #### Special elements
*
* Some HTML elements are handled in a special way; their start and end tags
* act like a void tag. These are special because their contents can't contain
* HTML markup. Everything inside these elements is handled in a special way
* and content that _appears_ like HTML tags inside of them isn't. There can
* be no nesting in these elements.
*
* In the following list, "raw text" means that all of the content in the HTML
* until the matching closing tag is treated verbatim without any replacements
* and without any parsing.
*
* - IFRAME allows no content but requires a closing tag.
* - NOEMBED (deprecated) content is raw text.
* - NOFRAMES (deprecated) content is raw text.
* - SCRIPT content is plaintext apart from legacy rules allowing `</script>` inside an HTML comment.
* - STYLE content is raw text.
* - TITLE content is plain text but character references are decoded.
* - TEXTAREA content is plain text but character references are decoded.
* - XMP (deprecated) content is raw text.
*
* ### Modifying HTML attributes for a found tag
*
* Once you've found the start of an opening tag you can modify
* any number of the attributes on that tag. You can set a new
* value for an attribute, remove the entire attribute, or do
* nothing and move on to the next opening tag.
*
* Example:
*
* if ( $tags->next_tag( array( 'class_name' => 'wp-group-block' ) ) ) {
* $tags->set_attribute( 'title', 'This groups the contained content.' );
* $tags->remove_attribute( 'data-test-id' );
* }
*
* If `set_attribute()` is called for an existing attribute it will
* overwrite the existing value. Similarly, calling `remove_attribute()`
* for a non-existing attribute has no effect on the document. Both
* of these methods are safe to call without knowing if a given attribute
* exists beforehand.
*
* ### Modifying CSS classes for a found tag
*
* The tag processor treats the `class` attribute as a special case.
* Because it's a common operation to add or remove CSS classes, this
* interface adds helper methods to make that easier.
*
* As with attribute values, adding or removing CSS classes is a safe
* operation that doesn't require checking if the attribute or class
* exists before making changes. If removing the only class then the
* entire `class` attribute will be removed.
*
* Example:
*
* // from `<span>Yippee!</span>`
* // to `<span class="is-active">Yippee!</span>`
* $tags->add_class( 'is-active' );
*
* // from `<span class="excited">Yippee!</span>`
* // to `<span class="excited is-active">Yippee!</span>`
* $tags->add_class( 'is-active' );
*
* // from `<span class="is-active heavy-accent">Yippee!</span>`
* // to `<span class="is-active heavy-accent">Yippee!</span>`
* $tags->add_class( 'is-active' );
*
* // from `<input type="text" class="is-active rugby not-disabled" length="24">`
* // to `<input type="text" class="is-active not-disabled" length="24">
* $tags->remove_class( 'rugby' );
*
* // from `<input type="text" class="rugby" length="24">`
* // to `<input type="text" length="24">
* $tags->remove_class( 'rugby' );
*
* // from `<input type="text" length="24">`
* // to `<input type="text" length="24">
* $tags->remove_class( 'rugby' );
*
* When class changes are enqueued but a direct change to `class` is made via
* `set_attribute` then the changes to `set_attribute` (or `remove_attribute`)
* will take precedence over those made through `add_class` and `remove_class`.
*
* ### Bookmarks
*
* While scanning through the input HTMl document it's possible to set
* a named bookmark when a particular tag is found. Later on, after
* continuing to scan other tags, it's possible to `seek` to one of
* the set bookmarks and then proceed again from that point forward.
*
* Because bookmarks create processing overhead one should avoid
* creating too many of them. As a rule, create only bookmarks
* of known string literal names; avoid creating "mark_{$index}"
* and so on. It's fine from a performance standpoint to create a
* bookmark and update it frequently, such as within a loop.
*
* $total_todos = 0;
* while ( $p->next_tag( array( 'tag_name' => 'UL', 'class_name' => 'todo' ) ) ) {
* $p->set_bookmark( 'list-start' );
* while ( $p->next_tag( array( 'tag_closers' => 'visit' ) ) ) {
* if ( 'UL' === $p->get_tag() && $p->is_tag_closer() ) {
* $p->set_bookmark( 'list-end' );
* $p->seek( 'list-start' );
* $p->set_attribute( 'data-contained-todos', (string) $total_todos );
* $total_todos = 0;
* $p->seek( 'list-end' );
* break;
* }
*
* if ( 'LI' === $p->get_tag() && ! $p->is_tag_closer() ) {
* $total_todos++;
* }
* }
* }
*
* ## Tokens and finer-grained processing.
*
* It's possible to scan through every lexical token in the
* HTML document using the `next_token()` function. This
* alternative form takes no argument and provides no built-in
* query syntax.
*
* Example:
*
* $title = '(untitled)';
* $text = '';
* while ( $processor->next_token() ) {
* switch ( $processor->get_token_name() ) {
* case '#text':
* $text .= $processor->get_modifiable_text();
* break;
*
* case 'BR':
* $text .= "\n";
* break;
*
* case 'TITLE':
* $title = $processor->get_modifiable_text();
* break;
* }
* }
* return trim( "# {$title}\n\n{$text}" );
*
* ### Tokens and _modifiable text_.
*
* #### Special "atomic" HTML elements.
*
* Not all HTML elements are able to contain other elements inside of them.
* For instance, the contents inside a TITLE element are plaintext (except
* that character references like & will be decoded). This means that
* if the string `<img>` appears inside a TITLE element, then it's not an
* image tag, but rather it's text describing an image tag. Likewise, the
* contents of a SCRIPT or STYLE element are handled entirely separately in
* a browser than the contents of other elements because they represent a
* different language than HTML.
*
* For these elements the Tag Processor treats the entire sequence as one,
* from the opening tag, including its contents, through its closing tag.
* This means that the it's not possible to match the closing tag for a
* SCRIPT element unless it's unexpected; the Tag Processor already matched
* it when it found the opening tag.
*
* The inner contents of these elements are that element's _modifiable text_.
*
* The special elements are:
* - `SCRIPT` whose contents are treated as raw plaintext but supports a legacy
* style of including Javascript inside of HTML comments to avoid accidentally
* closing the SCRIPT from inside a Javascript string. E.g. `console.log( '</script>' )`.
* - `TITLE` and `TEXTAREA` whose contents are treated as plaintext and then any
* character references are decoded. E.g. `1 < 2 < 3` becomes `1 < 2 < 3`.
* - `IFRAME`, `NOSCRIPT`, `NOEMBED`, `NOFRAME`, `STYLE` whose contents are treated as
* raw plaintext and left as-is. E.g. `1 < 2 < 3` remains `1 < 2 < 3`.
*
* #### Other tokens with modifiable text.
*
* There are also non-elements which are void/self-closing in nature and contain
* modifiable text that is part of that individual syntax token itself.
*
* - `#text` nodes, whose entire token _is_ the modifiable text.
* - HTML comments and tokens that become comments due to some syntax error. The
* text for these tokens is the portion of the comment inside of the syntax.
* E.g. for `<!-- comment -->` the text is `" comment "` (note the spaces are included).
* - `CDATA` sections, whose text is the content inside of the section itself. E.g. for
* `<![CDATA[some content]]>` the text is `"some content"` (with restrictions [1]).
* - "Funky comments," which are a special case of invalid closing tags whose name is
* invalid. The text for these nodes is the text that a browser would transform into
* an HTML comment when parsing. E.g. for `</%post_author>` the text is `%post_author`.
* - `DOCTYPE` declarations like `<DOCTYPE html>` which have no closing tag.
* - XML Processing instruction nodes like `<?wp __( "Like" ); ?>` (with restrictions [2]).
* - The empty end tag `</>` which is ignored in the browser and DOM.
*
* [1]: There are no CDATA sections in HTML. When encountering `<![CDATA[`, everything
* until the next `>` becomes a bogus HTML comment, meaning there can be no CDATA
* section in an HTML document containing `>`. The Tag Processor will first find
* all valid and bogus HTML comments, and then if the comment _would_ have been a
* CDATA section _were they to exist_, it will indicate this as the type of comment.
*
* [2]: XML allows a broader range of characters in a processing instruction's target name
* and disallows "xml" as a name, since it's special. The Tag Processor only recognizes
* target names with an ASCII-representable subset of characters. It also exhibits the
* same constraint as with CDATA sections, in that `>` cannot exist within the token
* since Processing Instructions do no exist within HTML and their syntax transforms
* into a bogus comment in the DOM.
*
* ## Design and limitations
*
* The Tag Processor is designed to linearly scan HTML documents and tokenize
* HTML tags and their attributes. It's designed to do this as efficiently as
* possible without compromising parsing integrity. Therefore it will be
* slower than some methods of modifying HTML, such as those incorporating
* over-simplified PCRE patterns, but will not introduce the defects and
* failures that those methods bring in, which lead to broken page renders
* and often to security vulnerabilities. On the other hand, it will be faster
* than full-blown HTML parsers such as DOMDocument and use considerably
* less memory. It requires a negligible memory overhead, enough to consider
* it a zero-overhead system.
*
* The performance characteristics are maintained by avoiding tree construction
* and semantic cleanups which are specified in HTML5. Because of this, for
* example, it's not possible for the Tag Processor to associate any given
* opening tag with its corresponding closing tag, or to return the inner markup
* inside an element. Systems may be built on top of the Tag Processor to do
* this, but the Tag Processor is and should be constrained so it can remain an
* efficient, low-level, and reliable HTML scanner.
*
* The Tag Processor's design incorporates a "garbage-in-garbage-out" philosophy.
* HTML5 specifies that certain invalid content be transformed into different forms
* for display, such as removing null bytes from an input document and replacing
* invalid characters with the Unicode replacement character `U+FFFD` (visually "�").
* Where errors or transformations exist within the HTML5 specification, the Tag Processor
* leaves those invalid inputs untouched, passing them through to the final browser
* to handle. While this implies that certain operations will be non-spec-compliant,
* such as reading the value of an attribute with invalid content, it also preserves a
* simplicity and efficiency for handling those error cases.
*
* Most operations within the Tag Processor are designed to minimize the difference
* between an input and output document for any given change. For example, the
* `add_class` and `remove_class` methods preserve whitespace and the class ordering
* within the `class` attribute; and when encountering tags with duplicated attributes,
* the Tag Processor will leave those invalid duplicate attributes where they are but
* update the proper attribute which the browser will read for parsing its value. An
* exception to this rule is that all attribute updates store their values as
* double-quoted strings, meaning that attributes on input with single-quoted or
* unquoted values will appear in the output with double-quotes.
*
* ### Scripting Flag
*
* The Tag Processor parses HTML with the "scripting flag" disabled. This means
* that it doesn't run any scripts while parsing the page. In a browser with
* JavaScript enabled, for example, the script can change the parse of the
* document as it loads. On the server, however, evaluating JavaScript is not
* only impractical, but also unwanted.
*
* Practically this means that the Tag Processor will descend into NOSCRIPT
* elements and process its child tags. Were the scripting flag enabled, such
* as in a typical browser, the contents of NOSCRIPT are skipped entirely.
*
* This allows the HTML API to process the content that will be presented in
* a browser when scripting is disabled, but it offers a different view of a
* page than most browser sessions will experience. E.g. the tags inside the
* NOSCRIPT disappear.
*
* ### Text Encoding
*
* The Tag Processor assumes that the input HTML document is encoded with a
* text encoding compatible with 7-bit ASCII's '<', '>', '&', ';', '/', '=',
* "'", '"', 'a' - 'z', 'A' - 'Z', and the whitespace characters ' ', tab,
* carriage-return, newline, and form-feed.
*
* In practice, this includes almost every single-byte encoding as well as
* UTF-8. Notably, however, it does not include UTF-16. If providing input
* that's incompatible, then convert the encoding beforehand.
*
* @since 6.2.0
* @since 6.2.1 Fix: Support for various invalid comments; attribute updates are case-insensitive.
* @since 6.3.2 Fix: Skip HTML-like content inside rawtext elements such as STYLE.
* @since 6.5.0 Pauses processor when input ends in an incomplete syntax token.
* Introduces "special" elements which act like void elements, e.g. TITLE, STYLE.
* Allows scanning through all tokens and processing modifiable text, where applicable.
*/
class WP_HTML_Tag_Processor {
/**
* The maximum number of bookmarks allowed to exist at
* any given time.
*
* @since 6.2.0
* @var int
*
* @see WP_HTML_Tag_Processor::set_bookmark()
*/
const MAX_BOOKMARKS = 10;
/**
* Maximum number of times seek() can be called.
* Prevents accidental infinite loops.
*
* @since 6.2.0
* @var int
*
* @see WP_HTML_Tag_Processor::seek()
*/
const MAX_SEEK_OPS = 1000;
/**
* The HTML document to parse.
*
* @since 6.2.0
* @var string
*/
protected $html;
/**
* The last query passed to next_tag().
*
* @since 6.2.0
* @var array|null
*/
private $last_query;
/**
* The tag name this processor currently scans for.
*
* @since 6.2.0
* @var string|null
*/
private $sought_tag_name;
/**
* The CSS class name this processor currently scans for.
*
* @since 6.2.0
* @var string|null
*/
private $sought_class_name;
/**
* The match offset this processor currently scans for.
*
* @since 6.2.0
* @var int|null
*/
private $sought_match_offset;
/**
* Whether to visit tag closers, e.g. </div>, when walking an input document.
*
* @since 6.2.0
* @var bool
*/
private $stop_on_tag_closers;
/**
* Specifies mode of operation of the parser at any given time.
*
* | State | Meaning |
* | ----------------|----------------------------------------------------------------------|
* | *Ready* | The parser is ready to run. |
* | *Complete* | There is nothing left to parse. |
* | *Incomplete* | The HTML ended in the middle of a token; nothing more can be parsed. |
* | *Matched tag* | Found an HTML tag; it's possible to modify its attributes. |
* | *Text node* | Found a #text node; this is plaintext and modifiable. |
* | *CDATA node* | Found a CDATA section; this is modifiable. |
* | *Comment* | Found a comment or bogus comment; this is modifiable. |
* | *Presumptuous* | Found an empty tag closer: `</>`. |
* | *Funky comment* | Found a tag closer with an invalid tag name; this is modifiable. |
*
* @since 6.5.0
*
* @see WP_HTML_Tag_Processor::STATE_READY
* @see WP_HTML_Tag_Processor::STATE_COMPLETE
* @see WP_HTML_Tag_Processor::STATE_INCOMPLETE_INPUT
* @see WP_HTML_Tag_Processor::STATE_MATCHED_TAG
* @see WP_HTML_Tag_Processor::STATE_TEXT_NODE
* @see WP_HTML_Tag_Processor::STATE_CDATA_NODE
* @see WP_HTML_Tag_Processor::STATE_COMMENT
* @see WP_HTML_Tag_Processor::STATE_DOCTYPE
* @see WP_HTML_Tag_Processor::STATE_PRESUMPTUOUS_TAG
* @see WP_HTML_Tag_Processor::STATE_FUNKY_COMMENT
*
* @var string
*/
protected $parser_state = self::STATE_READY;
/**
* What kind of syntax token became an HTML comment.
*
* Since there are many ways in which HTML syntax can create an HTML comment,
* this indicates which of those caused it. This allows the Tag Processor to
* represent more from the original input document than would appear in the DOM.
*
* @since 6.5.0
*
* @var string|null
*/
protected $comment_type = null;
/**
* How many bytes from the original HTML document have been read and parsed.
*
* This value points to the latest byte offset in the input document which
* has been already parsed. It is the internal cursor for the Tag Processor
* and updates while scanning through the HTML tokens.
*
* @since 6.2.0
* @var int
*/
private $bytes_already_parsed = 0;
/**
* Byte offset in input document where current token starts.
*
* Example:
*
* <div id="test">...
* 01234
* - token starts at 0
*
* @since 6.5.0
*
* @var int|null
*/
private $token_starts_at;
/**
* Byte length of current token.
*
* Example:
*
* <div id="test">...
* 012345678901234
* - token length is 14 - 0 = 14
*
* a <!-- comment --> is a token.
* 0123456789 123456789 123456789
* - token length is 17 - 2 = 15
*
* @since 6.5.0
*
* @var int|null
*/
private $token_length;
/**
* Byte offset in input document where current tag name starts.
*
* Example:
*
* <div id="test">...
* 01234
* - tag name starts at 1
*
* @since 6.2.0
*
* @var int|null
*/
private $tag_name_starts_at;
/**
* Byte length of current tag name.
*
* Example:
*
* <div id="test">...
* 01234
* --- tag name length is 3
*
* @since 6.2.0
*
* @var int|null
*/
private $tag_name_length;
/**
* Byte offset into input document where current modifiable text starts.
*
* @since 6.5.0
*
* @var int
*/
private $text_starts_at;
/**
* Byte length of modifiable text.
*
* @since 6.5.0
*
* @var string
*/
private $text_length;
/**
* Whether the current tag is an opening tag, e.g. <div>, or a closing tag, e.g. </div>.
*
* @var bool
*/
private $is_closing_tag;
/**
* Lazily-built index of attributes found within an HTML tag, keyed by the attribute name.
*
* Example:
*
* // Supposing the parser is working through this content
* // and stops after recognizing the `id` attribute.
* // <div id="test-4" class=outline title="data:text/plain;base64=asdk3nk1j3fo8">
* // ^ parsing will continue from this point.
* $this->attributes = array(
* 'id' => new WP_HTML_Attribute_Token( 'id', 9, 6, 5, 11, false )
* );
*
* // When picking up parsing again, or when asking to find the
* // `class` attribute we will continue and add to this array.
* $this->attributes = array(
* 'id' => new WP_HTML_Attribute_Token( 'id', 9, 6, 5, 11, false ),
* 'class' => new WP_HTML_Attribute_Token( 'class', 23, 7, 17, 13, false )
* );
*
* // Note that only the `class` attribute value is stored in the index.
* // That's because it is the only value used by this class at the moment.
*
* @since 6.2.0
* @var WP_HTML_Attribute_Token[]
*/
private $attributes = array();
/**
* Tracks spans of duplicate attributes on a given tag, used for removing
* all copies of an attribute when calling `remove_attribute()`.
*
* @since 6.3.2
*
* @var (WP_HTML_Span[])[]|null
*/
private $duplicate_attributes = null;
/**
* Which class names to add or remove from a tag.
*
* These are tracked separately from attribute updates because they are
* semantically distinct, whereas this interface exists for the common
* case of adding and removing class names while other attributes are
* generally modified as with DOM `setAttribute` calls.
*
* When modifying an HTML document these will eventually be collapsed
* into a single `set_attribute( 'class', $changes )` call.
*
* Example:
*
* // Add the `wp-block-group` class, remove the `wp-group` class.
* $classname_updates = array(
* // Indexed by a comparable class name.
* 'wp-block-group' => WP_HTML_Tag_Processor::ADD_CLASS,
* 'wp-group' => WP_HTML_Tag_Processor::REMOVE_CLASS
* );
*
* @since 6.2.0
* @var bool[]
*/
private $classname_updates = array();
/**
* Tracks a semantic location in the original HTML which
* shifts with updates as they are applied to the document.
*
* @since 6.2.0
* @var WP_HTML_Span[]
*/
protected $bookmarks = array();
const ADD_CLASS = true;
const REMOVE_CLASS = false;
const SKIP_CLASS = null;
/**
* Lexical replacements to apply to input HTML document.
*
* "Lexical" in this class refers to the part of this class which
* operates on pure text _as text_ and not as HTML. There's a line
* between the public interface, with HTML-semantic methods like
* `set_attribute` and `add_class`, and an internal state that tracks
* text offsets in the input document.
*
* When higher-level HTML methods are called, those have to transform their
* operations (such as setting an attribute's value) into text diffing
* operations (such as replacing the sub-string from indices A to B with
* some given new string). These text-diffing operations are the lexical
* updates.
*
* As new higher-level methods are added they need to collapse their
* operations into these lower-level lexical updates since that's the
* Tag Processor's internal language of change. Any code which creates
* these lexical updates must ensure that they do not cross HTML syntax
* boundaries, however, so these should never be exposed outside of this
* class or any classes which intentionally expand its functionality.
*
* These are enqueued while editing the document instead of being immediately
* applied to avoid processing overhead, string allocations, and string
* copies when applying many updates to a single document.
*
* Example:
*
* // Replace an attribute stored with a new value, indices
* // sourced from the lazily-parsed HTML recognizer.
* $start = $attributes['src']->start;
* $length = $attributes['src']->length;
* $modifications[] = new WP_HTML_Text_Replacement( $start, $length, $new_value );
*
* // Correspondingly, something like this will appear in this array.
* $lexical_updates = array(
* WP_HTML_Text_Replacement( 14, 28, 'https://my-site.my-domain/wp-content/uploads/2014/08/kittens.jpg' )
* );
*
* @since 6.2.0
* @var WP_HTML_Text_Replacement[]
*/
protected $lexical_updates = array();
/**
* Tracks and limits `seek()` calls to prevent accidental infinite loops.
*
* @since 6.2.0
* @var int
*
* @see WP_HTML_Tag_Processor::seek()
*/
protected $seek_count = 0;
/**
* Constructor.
*
* @since 6.2.0
*
* @param string $html HTML to process.
*/
public function __construct( $html ) {
$this->html = $html;
}
/**
* Finds the next tag matching the $query.
*
* @since 6.2.0
* @since 6.5.0 No longer processes incomplete tokens at end of document; pauses the processor at start of token.
*
* @param array|string|null $query {
* Optional. Which tag name to find, having which class, etc. Default is to find any tag.
*
* @type string|null $tag_name Which tag to find, or `null` for "any tag."
* @type int|null $match_offset Find the Nth tag matching all search criteria.
* 1 for "first" tag, 3 for "third," etc.
* Defaults to first tag.
* @type string|null $class_name Tag must contain this whole class name to match.
* @type string|null $tag_closers "visit" or "skip": whether to stop on tag closers, e.g. </div>.
* }
* @return bool Whether a tag was matched.
*/
public function next_tag( $query = null ) {
$this->parse_query( $query );
$already_found = 0;
do {
if ( false === $this->next_token() ) {
return false;
}
if ( self::STATE_MATCHED_TAG !== $this->parser_state ) {
continue;
}
if ( $this->matches() ) {
++$already_found;
}
} while ( $already_found < $this->sought_match_offset );
return true;
}
/**
* Finds the next token in the HTML document.
*
* An HTML document can be viewed as a stream of tokens,
* where tokens are things like HTML tags, HTML comments,
* text nodes, etc. This method finds the next token in
* the HTML document and returns whether it found one.
*
* If it starts parsing a token and reaches the end of the
* document then it will seek to the start of the last
* token and pause, returning `false` to indicate that it
* failed to find a complete token.
*
* Possible token types, based on the HTML specification:
*
* - an HTML tag, whether opening, closing, or void.
* - a text node - the plaintext inside tags.
* - an HTML comment.
* - a DOCTYPE declaration.
* - a processing instruction, e.g. `<?xml version="1.0" ?>`.
*
* The Tag Processor currently only supports the tag token.
*
* @since 6.5.0
*
* @return bool Whether a token was parsed.
*/
public function next_token() {
return $this->base_class_next_token();
}
/**
* Internal method which finds the next token in the HTML document.
*
* This method is a protected internal function which implements the logic for
* finding the next token in a document. It exists so that the parser can update
* its state without affecting the location of the cursor in the document and
* without triggering subclass methods for things like `next_token()`, e.g. when
* applying patches before searching for the next token.
*
* @since 6.5.0
*
* @access private
*
* @return bool Whether a token was parsed.
*/
private function base_class_next_token() {
$was_at = $this->bytes_already_parsed;
$this->after_tag();
// Don't proceed if there's nothing more to scan.
if (
self::STATE_COMPLETE === $this->parser_state ||
self::STATE_INCOMPLETE_INPUT === $this->parser_state
) {
return false;
}
/*
* The next step in the parsing loop determines the parsing state;
* clear it so that state doesn't linger from the previous step.
*/
$this->parser_state = self::STATE_READY;
if ( $this->bytes_already_parsed >= strlen( $this->html ) ) {
$this->parser_state = self::STATE_COMPLETE;
return false;
}
// Find the next tag if it exists.
if ( false === $this->parse_next_tag() ) {
if ( self::STATE_INCOMPLETE_INPUT === $this->parser_state ) {
$this->bytes_already_parsed = $was_at;
}
return false;
}
/*
* For legacy reasons the rest of this function handles tags and their
* attributes. If the processor has reached the end of the document
* or if it matched any other token then it should return here to avoid
* attempting to process tag-specific syntax.
*/
if (
self::STATE_INCOMPLETE_INPUT !== $this->parser_state &&
self::STATE_COMPLETE !== $this->parser_state &&
self::STATE_MATCHED_TAG !== $this->parser_state
) {
return true;
}
// Parse all of its attributes.
while ( $this->parse_next_attribute() ) {
continue;
}
// Ensure that the tag closes before the end of the document.
if (
self::STATE_INCOMPLETE_INPUT === $this->parser_state ||
$this->bytes_already_parsed >= strlen( $this->html )
) {
// Does this appropriately clear state (parsed attributes)?
$this->parser_state = self::STATE_INCOMPLETE_INPUT;
$this->bytes_already_parsed = $was_at;
return false;
}
$tag_ends_at = strpos( $this->html, '>', $this->bytes_already_parsed );
if ( false === $tag_ends_at ) {
$this->parser_state = self::STATE_INCOMPLETE_INPUT;
$this->bytes_already_parsed = $was_at;
return false;
}
$this->parser_state = self::STATE_MATCHED_TAG;
$this->token_length = $tag_ends_at - $this->token_starts_at;
$this->bytes_already_parsed = $tag_ends_at + 1;
/*
* For non-DATA sections which might contain text that looks like HTML tags but
* isn't, scan with the appropriate alternative mode. Looking at the first letter
* of the tag name as a pre-check avoids a string allocation when it's not needed.
*/
$t = $this->html[ $this->tag_name_starts_at ];
if (
$this->is_closing_tag ||
! (
'i' === $t || 'I' === $t ||
'n' === $t || 'N' === $t ||
's' === $t || 'S' === $t ||
't' === $t || 'T' === $t ||
'x' === $t || 'X' === $t
)
) {
return true;
}
$tag_name = $this->get_tag();
/*
* Preserve the opening tag pointers, as these will be overwritten
* when finding the closing tag. They will be reset after finding
* the closing to tag to point to the opening of the special atomic
* tag sequence.
*/
$tag_name_starts_at = $this->tag_name_starts_at;
$tag_name_length = $this->tag_name_length;
$tag_ends_at = $this->token_starts_at + $this->token_length;
$attributes = $this->attributes;
$duplicate_attributes = $this->duplicate_attributes;
// Find the closing tag if necessary.
$found_closer = false;
switch ( $tag_name ) {
case 'SCRIPT':
$found_closer = $this->skip_script_data();
break;
case 'TEXTAREA':
case 'TITLE':
$found_closer = $this->skip_rcdata( $tag_name );
break;
/*
* In the browser this list would include the NOSCRIPT element,
* but the Tag Processor is an environment with the scripting
* flag disabled, meaning that it needs to descend into the
* NOSCRIPT element to be able to properly process what will be
* sent to a browser.
*
* Note that this rule makes HTML5 syntax incompatible with XML,
* because the parsing of this token depends on client application.
* The NOSCRIPT element cannot be represented in the XHTML syntax.
*/
case 'IFRAME':
case 'NOEMBED':
case 'NOFRAMES':
case 'STYLE':
case 'XMP':
$found_closer = $this->skip_rawtext( $tag_name );
break;
// No other tags should be treated in their entirety here.
default:
return true;
}
if ( ! $found_closer ) {
$this->parser_state = self::STATE_INCOMPLETE_INPUT;
$this->bytes_already_parsed = $was_at;
return false;
}
/*
* The values here look like they reference the opening tag but they reference
* the closing tag instead. This is why the opening tag values were stored
* above in a variable. It reads confusingly here, but that's because the
* functions that skip the contents have moved all the internal cursors past
* the inner content of the tag.
*/
$this->token_starts_at = $was_at;
$this->token_length = $this->bytes_already_parsed - $this->token_starts_at;
$this->text_starts_at = $tag_ends_at + 1;
$this->text_length = $this->tag_name_starts_at - $this->text_starts_at;
$this->tag_name_starts_at = $tag_name_starts_at;
$this->tag_name_length = $tag_name_length;
$this->attributes = $attributes;
$this->duplicate_attributes = $duplicate_attributes;
return true;
}
/**
* Whether the processor paused because the input HTML document ended
* in the middle of a syntax element, such as in the middle of a tag.
*
* Example:
*
* $processor = new WP_HTML_Tag_Processor( '<input type="text" value="Th' );
* false === $processor->get_next_tag();
* true === $processor->paused_at_incomplete_token();
*
* @since 6.5.0
*
* @return bool Whether the parse paused at the start of an incomplete token.
*/
public function paused_at_incomplete_token() {
return self::STATE_INCOMPLETE_INPUT === $this->parser_state;
}
/**
* Generator for a foreach loop to step through each class name for the matched tag.
*
* This generator function is designed to be used inside a "foreach" loop.
*
* Example:
*
* $p = new WP_HTML_Tag_Processor( "<div class='free <egg<\tlang-en'>" );
* $p->next_tag();
* foreach ( $p->class_list() as $class_name ) {
* echo "{$class_name} ";
* }
* // Outputs: "free <egg> lang-en "
*
* @since 6.4.0
*/
public function class_list() {
if ( self::STATE_MATCHED_TAG !== $this->parser_state ) {
return;
}
/** @var string $class contains the string value of the class attribute, with character references decoded. */
$class = $this->get_attribute( 'class' );
if ( ! is_string( $class ) ) {
return;
}
$seen = array();
$at = 0;
while ( $at < strlen( $class ) ) {
// Skip past any initial boundary characters.
$at += strspn( $class, " \t\f\r\n", $at );
if ( $at >= strlen( $class ) ) {
return;
}
// Find the byte length until the next boundary.
$length = strcspn( $class, " \t\f\r\n", $at );
if ( 0 === $length ) {
return;
}
/*
* CSS class names are case-insensitive in the ASCII range.
*
* @see https://www.w3.org/TR/CSS2/syndata.html#x1
*/
$name = strtolower( substr( $class, $at, $length ) );
$at += $length;
/*
* It's expected that the number of class names for a given tag is relatively small.
* Given this, it is probably faster overall to scan an array for a value rather
* than to use the class name as a key and check if it's a key of $seen.
*/
if ( in_array( $name, $seen, true ) ) {
continue;
}
$seen[] = $name;
yield $name;
}
}
/**
* Returns if a matched tag contains the given ASCII case-insensitive class name.
*
* @since 6.4.0
*
* @param string $wanted_class Look for this CSS class name, ASCII case-insensitive.
* @return bool|null Whether the matched tag contains the given class name, or null if not matched.
*/
public function has_class( $wanted_class ) {
if ( self::STATE_MATCHED_TAG !== $this->parser_state ) {
return null;
}
$wanted_class = strtolower( $wanted_class );
foreach ( $this->class_list() as $class_name ) {
if ( $class_name === $wanted_class ) {
return true;
}
}
return false;
}
/**
* Sets a bookmark in the HTML document.
*
* Bookmarks represent specific places or tokens in the HTML
* document, such as a tag opener or closer. When applying
* edits to a document, such as setting an attribute, the
* text offsets of that token may shift; the bookmark is
* kept updated with those shifts and remains stable unless
* the entire span of text in which the token sits is removed.
*
* Release bookmarks when they are no longer needed.
*
* Example:
*
* <main><h2>Surprising fact you may not know!</h2></main>
* ^ ^
* \-|-- this `H2` opener bookmark tracks the token
*
* <main class="clickbait"><h2>Surprising fact you may no…
* ^ ^
* \-|-- it shifts with edits
*
* Bookmarks provide the ability to seek to a previously-scanned
* place in the HTML document. This avoids the need to re-scan
* the entire document.
*
* Example:
*
* <ul><li>One</li><li>Two</li><li>Three</li></ul>
* ^^^^
* want to note this last item
*
* $p = new WP_HTML_Tag_Processor( $html );
* $in_list = false;
* while ( $p->next_tag( array( 'tag_closers' => $in_list ? 'visit' : 'skip' ) ) ) {
* if ( 'UL' === $p->get_tag() ) {
* if ( $p->is_tag_closer() ) {
* $in_list = false;
* $p->set_bookmark( 'resume' );
* if ( $p->seek( 'last-li' ) ) {
* $p->add_class( 'last-li' );
* }
* $p->seek( 'resume' );
* $p->release_bookmark( 'last-li' );
* $p->release_bookmark( 'resume' );
* } else {
* $in_list = true;
* }
* }
*
* if ( 'LI' === $p->get_tag() ) {
* $p->set_bookmark( 'last-li' );
* }
* }
*
* Bookmarks intentionally hide the internal string offsets
* to which they refer. They are maintained internally as
* updates are applied to the HTML document and therefore
* retain their "position" - the location to which they
* originally pointed. The inability to use bookmarks with
* functions like `substr` is therefore intentional to guard
* against accidentally breaking the HTML.
*
* Because bookmarks allocate memory and require processing
* for every applied update, they are limited and require
* a name. They should not be created with programmatically-made
* names, such as "li_{$index}" with some loop. As a general
* rule they should only be created with string-literal names
* like "start-of-section" or "last-paragraph".
*
* Bookmarks are a powerful tool to enable complicated behavior.
* Consider double-checking that you need this tool if you are
* reaching for it, as inappropriate use could lead to broken
* HTML structure or unwanted processing overhead.
*
* @since 6.2.0
*
* @param string $name Identifies this particular bookmark.
* @return bool Whether the bookmark was successfully created.
*/
public function set_bookmark( $name ) {
// It only makes sense to set a bookmark if the parser has paused on a concrete token.
if (
self::STATE_COMPLETE === $this->parser_state ||
self::STATE_INCOMPLETE_INPUT === $this->parser_state
) {
return false;
}
if ( ! array_key_exists( $name, $this->bookmarks ) && count( $this->bookmarks ) >= static::MAX_BOOKMARKS ) {
_doing_it_wrong(
__METHOD__,
__( 'Too many bookmarks: cannot create any more.' ),
'6.2.0'
);
return false;
}
$this->bookmarks[ $name ] = new WP_HTML_Span( $this->token_starts_at, $this->token_length );
return true;
}
/**
* Removes a bookmark that is no longer needed.
*
* Releasing a bookmark frees up the small
* performance overhead it requires.
*
* @param string $name Name of the bookmark to remove.
* @return bool Whether the bookmark already existed before removal.
*/
public function release_bookmark( $name ) {
if ( ! array_key_exists( $name, $this->bookmarks ) ) {
return false;
}
unset( $this->bookmarks[ $name ] );
return true;
}
/**
* Skips contents of generic rawtext elements.
*
* @since 6.3.2
*
* @see https://html.spec.whatwg.org/#generic-raw-text-element-parsing-algorithm
*
* @param string $tag_name The uppercase tag name which will close the RAWTEXT region.
* @return bool Whether an end to the RAWTEXT region was found before the end of the document.
*/
private function skip_rawtext( $tag_name ) {
/*
* These two functions distinguish themselves on whether character references are
* decoded, and since functionality to read the inner markup isn't supported, it's
* not necessary to implement these two functions separately.
*/
return $this->skip_rcdata( $tag_name );
}
/**
* Skips contents of RCDATA elements, namely title and textarea tags.
*
* @since 6.2.0
*
* @see https://html.spec.whatwg.org/multipage/parsing.html#rcdata-state
*
* @param string $tag_name The uppercase tag name which will close the RCDATA region.
* @return bool Whether an end to the RCDATA region was found before the end of the document.
*/
private function skip_rcdata( $tag_name ) {
$html = $this->html;
$doc_length = strlen( $html );
$tag_length = strlen( $tag_name );
$at = $this->bytes_already_parsed;
while ( false !== $at && $at < $doc_length ) {
$at = strpos( $this->html, '</', $at );
$this->tag_name_starts_at = $at;
// Fail if there is no possible tag closer.
if ( false === $at || ( $at + $tag_length ) >= $doc_length ) {
return false;
}
$at += 2;
/*
* Find a case-insensitive match to the tag name.
*
* Because tag names are limited to US-ASCII there is no
* need to perform any kind of Unicode normalization when
* comparing; any character which could be impacted by such
* normalization could not be part of a tag name.
*/
for ( $i = 0; $i < $tag_length; $i++ ) {
$tag_char = $tag_name[ $i ];
$html_char = $html[ $at + $i ];
if ( $html_char !== $tag_char && strtoupper( $html_char ) !== $tag_char ) {
$at += $i;
continue 2;
}
}
$at += $tag_length;
$this->bytes_already_parsed = $at;
if ( $at >= strlen( $html ) ) {
return false;
}
/*
* Ensure that the tag name terminates to avoid matching on
* substrings of a longer tag name. For example, the sequence
* "</textarearug" should not match for "</textarea" even
* though "textarea" is found within the text.
*/
$c = $html[ $at ];
if ( ' ' !== $c && "\t" !== $c && "\r" !== $c && "\n" !== $c && '/' !== $c && '>' !== $c ) {
continue;
}
while ( $this->parse_next_attribute() ) {
continue;
}
$at = $this->bytes_already_parsed;
if ( $at >= strlen( $this->html ) ) {
return false;
}
if ( '>' === $html[ $at ] ) {
$this->bytes_already_parsed = $at + 1;
return true;
}
if ( $at + 1 >= strlen( $this->html ) ) {
return false;
}
if ( '/' === $html[ $at ] && '>' === $html[ $at + 1 ] ) {
$this->bytes_already_parsed = $at + 2;
return true;
}
}
return false;
}
/**
* Skips contents of script tags.
*
* @since 6.2.0
*
* @return bool Whether the script tag was closed before the end of the document.
*/
private function skip_script_data() {
$state = 'unescaped';
$html = $this->html;
$doc_length = strlen( $html );
$at = $this->bytes_already_parsed;
while ( false !== $at && $at < $doc_length ) {
$at += strcspn( $html, '-<', $at );
/*
* For all script states a "-->" transitions
* back into the normal unescaped script mode,
* even if that's the current state.
*/
if (
$at + 2 < $doc_length &&
'-' === $html[ $at ] &&
'-' === $html[ $at + 1 ] &&
'>' === $html[ $at + 2 ]
) {
$at += 3;
$state = 'unescaped';
continue;
}
// Everything of interest past here starts with "<".
if ( $at + 1 >= $doc_length || '<' !== $html[ $at++ ] ) {
continue;
}
/*
* Unlike with "-->", the "<!--" only transitions
* into the escaped mode if not already there.
*
* Inside the escaped modes it will be ignored; and
* should never break out of the double-escaped
* mode and back into the escaped mode.
*
* While this requires a mode change, it does not
* impact the parsing otherwise, so continue
* parsing after updating the state.
*/
if (
$at + 2 < $doc_length &&
'!' === $html[ $at ] &&
'-' === $html[ $at + 1 ] &&
'-' === $html[ $at + 2 ]
) {
$at += 3;
$state = 'unescaped' === $state ? 'escaped' : $state;
continue;
}
if ( '/' === $html[ $at ] ) {
$closer_potentially_starts_at = $at - 1;
$is_closing = true;
++$at;
} else {
$is_closing = false;
}
/*
* At this point the only remaining state-changes occur with the
* <script> and </script> tags; unless one of these appears next,
* proceed scanning to the next potential token in the text.
*/
if ( ! (
$at + 6 < $doc_length &&
( 's' === $html[ $at ] || 'S' === $html[ $at ] ) &&
( 'c' === $html[ $at + 1 ] || 'C' === $html[ $at + 1 ] ) &&
( 'r' === $html[ $at + 2 ] || 'R' === $html[ $at + 2 ] ) &&
( 'i' === $html[ $at + 3 ] || 'I' === $html[ $at + 3 ] ) &&
( 'p' === $html[ $at + 4 ] || 'P' === $html[ $at + 4 ] ) &&
( 't' === $html[ $at + 5 ] || 'T' === $html[ $at + 5 ] )
) ) {
++$at;
continue;
}
/*
* Ensure that the script tag terminates to avoid matching on
* substrings of a non-match. For example, the sequence
* "<script123" should not end a script region even though
* "<script" is found within the text.
*/
if ( $at + 6 >= $doc_length ) {
continue;
}
$at += 6;
$c = $html[ $at ];
if ( ' ' !== $c && "\t" !== $c && "\r" !== $c && "\n" !== $c && '/' !== $c && '>' !== $c ) {
++$at;
continue;
}
if ( 'escaped' === $state && ! $is_closing ) {
$state = 'double-escaped';
continue;
}
if ( 'double-escaped' === $state && $is_closing ) {
$state = 'escaped';
continue;
}
if ( $is_closing ) {
$this->bytes_already_parsed = $closer_potentially_starts_at;
$this->tag_name_starts_at = $closer_potentially_starts_at;
if ( $this->bytes_already_parsed >= $doc_length ) {
return false;
}
while ( $this->parse_next_attribute() ) {
continue;
}
if ( $this->bytes_already_parsed >= $doc_length ) {
$this->parser_state = self::STATE_INCOMPLETE_INPUT;
return false;
}
if ( '>' === $html[ $this->bytes_already_parsed ] ) {
++$this->bytes_already_parsed;
return true;
}
}
++$at;
}
return false;
}
/**
* Parses the next tag.
*
* This will find and start parsing the next tag, including
* the opening `<`, the potential closer `/`, and the tag
* name. It does not parse the attributes or scan to the
* closing `>`; these are left for other methods.
*
* @since 6.2.0
* @since 6.2.1 Support abruptly-closed comments, invalid-tag-closer-comments, and empty elements.
*
* @return bool Whether a tag was found before the end of the document.
*/
private function parse_next_tag() {
$this->after_tag();
$html = $this->html;
$doc_length = strlen( $html );
$was_at = $this->bytes_already_parsed;
$at = $was_at;
while ( false !== $at && $at < $doc_length ) {
$at = strpos( $html, '<', $at );
/*
* This does not imply an incomplete parse; it indicates that there
* can be nothing left in the document other than a #text node.
*/
if ( false === $at ) {
$this->parser_state = self::STATE_TEXT_NODE;
$this->token_starts_at = $was_at;
$this->token_length = strlen( $html ) - $was_at;
$this->text_starts_at = $was_at;
$this->text_length = $this->token_length;
$this->bytes_already_parsed = strlen( $html );
return true;
}
if ( $at > $was_at ) {
/*
* A "<" normally starts a new HTML tag or syntax token, but in cases where the
* following character can't produce a valid token, the "<" is instead treated
* as plaintext and the parser should skip over it. This avoids a problem when
* following earlier practices of typing emoji with text, e.g. "<3". This
* should be a heart, not a tag. It's supposed to be rendered, not hidden.
*
* At this point the parser checks if this is one of those cases and if it is
* will continue searching for the next "<" in search of a token boundary.
*
* @see https://html.spec.whatwg.org/#tag-open-state
*/
if ( strlen( $html ) > $at + 1 ) {
$next_character = $html[ $at + 1 ];
$at_another_node = (
'!' === $next_character ||
'/' === $next_character ||
'?' === $next_character ||
( 'A' <= $next_character && $next_character <= 'Z' ) ||
( 'a' <= $next_character && $next_character <= 'z' )
);
if ( ! $at_another_node ) {
++$at;
continue;
}
}
$this->parser_state = self::STATE_TEXT_NODE;
$this->token_starts_at = $was_at;
$this->token_length = $at - $was_at;
$this->text_starts_at = $was_at;
$this->text_length = $this->token_length;
$this->bytes_already_parsed = $at;
return true;
}
$this->token_starts_at = $at;
if ( $at + 1 < $doc_length && '/' === $this->html[ $at + 1 ] ) {
$this->is_closing_tag = true;
++$at;
} else {
$this->is_closing_tag = false;
}
/*
* HTML tag names must start with [a-zA-Z] otherwise they are not tags.
* For example, "<3" is rendered as text, not a tag opener. If at least
* one letter follows the "<" then _it is_ a tag, but if the following
* character is anything else it _is not a tag_.
*
* It's not uncommon to find non-tags starting with `<` in an HTML
* document, so it's good for performance to make this pre-check before
* continuing to attempt to parse a tag name.
*
* Reference:
* * https://html.spec.whatwg.org/multipage/parsing.html#data-state
* * https://html.spec.whatwg.org/multipage/parsing.html#tag-open-state
*/
$tag_name_prefix_length = strspn( $html, 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ', $at + 1 );
if ( $tag_name_prefix_length > 0 ) {
++$at;
$this->parser_state = self::STATE_MATCHED_TAG;
$this->tag_name_starts_at = $at;
$this->tag_name_length = $tag_name_prefix_length + strcspn( $html, " \t\f\r\n/>", $at + $tag_name_prefix_length );
$this->bytes_already_parsed = $at + $this->tag_name_length;
return true;
}
/*
* Abort if no tag is found before the end of
* the document. There is nothing left to parse.
*/
if ( $at + 1 >= $doc_length ) {
$this->parser_state = self::STATE_INCOMPLETE_INPUT;
return false;
}
/*
* `<!` transitions to markup declaration open state
* https://html.spec.whatwg.org/multipage/parsing.html#markup-declaration-open-state
*/
if ( '!' === $html[ $at + 1 ] ) {
/*
* `<!--` transitions to a comment state – apply further comment rules.
* https://html.spec.whatwg.org/multipage/parsing.html#tag-open-state
*/
if (
$doc_length > $at + 3 &&
'-' === $html[ $at + 2 ] &&
'-' === $html[ $at + 3 ]
) {
$closer_at = $at + 4;
// If it's not possible to close the comment then there is nothing more to scan.
if ( $doc_length <= $closer_at ) {
$this->parser_state = self::STATE_INCOMPLETE_INPUT;
return false;
}
// Abruptly-closed empty comments are a sequence of dashes followed by `>`.
$span_of_dashes = strspn( $html, '-', $closer_at );
if ( '>' === $html[ $closer_at + $span_of_dashes ] ) {
/*
* @todo When implementing `set_modifiable_text()` ensure that updates to this token
* don't break the syntax for short comments, e.g. `<!--->`. Unlike other comment
* and bogus comment syntax, these leave no clear insertion point for text and
* they need to be modified specially in order to contain text. E.g. to store
* `?` as the modifiable text, the `<!--->` needs to become `<!--?-->`, which
* involves inserting an additional `-` into the token after the modifiable text.
*/
$this->parser_state = self::STATE_COMMENT;
$this->comment_type = self::COMMENT_AS_ABRUPTLY_CLOSED_COMMENT;
$this->token_length = $closer_at + $span_of_dashes + 1 - $this->token_starts_at;
// Only provide modifiable text if the token is long enough to contain it.
if ( $span_of_dashes >= 2 ) {
$this->comment_type = self::COMMENT_AS_HTML_COMMENT;
$this->text_starts_at = $this->token_starts_at + 4;
$this->text_length = $span_of_dashes - 2;
}
$this->bytes_already_parsed = $closer_at + $span_of_dashes + 1;
return true;
}
/*
* Comments may be closed by either a --> or an invalid --!>.
* The first occurrence closes the comment.
*
* See https://html.spec.whatwg.org/#parse-error-incorrectly-closed-comment
*/
--$closer_at; // Pre-increment inside condition below reduces risk of accidental infinite looping.
while ( ++$closer_at < $doc_length ) {
$closer_at = strpos( $html, '--', $closer_at );
if ( false === $closer_at ) {
$this->parser_state = self::STATE_INCOMPLETE_INPUT;
return false;
}
if ( $closer_at + 2 < $doc_length && '>' === $html[ $closer_at + 2 ] ) {
$this->parser_state = self::STATE_COMMENT;
$this->comment_type = self::COMMENT_AS_HTML_COMMENT;
$this->token_length = $closer_at + 3 - $this->token_starts_at;
$this->text_starts_at = $this->token_starts_at + 4;
$this->text_length = $closer_at - $this->text_starts_at;
$this->bytes_already_parsed = $closer_at + 3;
return true;
}
if (
$closer_at + 3 < $doc_length &&
'!' === $html[ $closer_at + 2 ] &&
'>' === $html[ $closer_at + 3 ]
) {
$this->parser_state = self::STATE_COMMENT;
$this->comment_type = self::COMMENT_AS_HTML_COMMENT;
$this->token_length = $closer_at + 4 - $this->token_starts_at;
$this->text_starts_at = $this->token_starts_at + 4;
$this->text_length = $closer_at - $this->text_starts_at;
$this->bytes_already_parsed = $closer_at + 4;
return true;
}
}
}
/*
* `<!DOCTYPE` transitions to DOCTYPE state – skip to the nearest >
* These are ASCII-case-insensitive.
* https://html.spec.whatwg.org/multipage/parsing.html#tag-open-state
*/
if (
$doc_length > $at + 8 &&
( 'D' === $html[ $at + 2 ] || 'd' === $html[ $at + 2 ] ) &&
( 'O' === $html[ $at + 3 ] || 'o' === $html[ $at + 3 ] ) &&
( 'C' === $html[ $at + 4 ] || 'c' === $html[ $at + 4 ] ) &&
( 'T' === $html[ $at + 5 ] || 't' === $html[ $at + 5 ] ) &&
( 'Y' === $html[ $at + 6 ] || 'y' === $html[ $at + 6 ] ) &&
( 'P' === $html[ $at + 7 ] || 'p' === $html[ $at + 7 ] ) &&
( 'E' === $html[ $at + 8 ] || 'e' === $html[ $at + 8 ] )
) {
$closer_at = strpos( $html, '>', $at + 9 );
if ( false === $closer_at ) {
$this->parser_state = self::STATE_INCOMPLETE_INPUT;
return false;
}
$this->parser_state = self::STATE_DOCTYPE;
$this->token_length = $closer_at + 1 - $this->token_starts_at;
$this->text_starts_at = $this->token_starts_at + 9;
$this->text_length = $closer_at - $this->text_starts_at;
$this->bytes_already_parsed = $closer_at + 1;
return true;
}
/*
* Anything else here is an incorrectly-opened comment and transitions
* to the bogus comment state - skip to the nearest >. If no closer is
* found then the HTML was truncated inside the markup declaration.
*/
$closer_at = strpos( $html, '>', $at + 1 );
if ( false === $closer_at ) {
$this->parser_state = self::STATE_INCOMPLETE_INPUT;
return false;
}
$this->parser_state = self::STATE_COMMENT;
$this->comment_type = self::COMMENT_AS_INVALID_HTML;
$this->token_length = $closer_at + 1 - $this->token_starts_at;
$this->text_starts_at = $this->token_starts_at + 2;
$this->text_length = $closer_at - $this->text_starts_at;
$this->bytes_already_parsed = $closer_at + 1;
/*
* Identify nodes that would be CDATA if HTML had CDATA sections.
*
* This section must occur after identifying the bogus comment end
* because in an HTML parser it will span to the nearest `>`, even
* if there's no `]]>` as would be required in an XML document. It
* is therefore not possible to parse a CDATA section containing
* a `>` in the HTML syntax.
*
* Inside foreign elements there is a discrepancy between browsers
* and the specification on this.
*
* @todo Track whether the Tag Processor is inside a foreign element
* and require the proper closing `]]>` in those cases.
*/
if (
$this->token_length >= 10 &&
'[' === $html[ $this->token_starts_at + 2 ] &&
'C' === $html[ $this->token_starts_at + 3 ] &&
'D' === $html[ $this->token_starts_at + 4 ] &&
'A' === $html[ $this->token_starts_at + 5 ] &&
'T' === $html[ $this->token_starts_at + 6 ] &&
'A' === $html[ $this->token_starts_at + 7 ] &&
'[' === $html[ $this->token_starts_at + 8 ] &&
']' === $html[ $closer_at - 1 ] &&
']' === $html[ $closer_at - 2 ]
) {
$this->parser_state = self::STATE_COMMENT;
$this->comment_type = self::COMMENT_AS_CDATA_LOOKALIKE;
$this->text_starts_at += 7;
$this->text_length -= 9;
}
return true;
}
/*
* </> is a missing end tag name, which is ignored.
*
* This was also known as the "presumptuous empty tag"
* in early discussions as it was proposed to close
* the nearest previous opening tag.
*
* See https://html.spec.whatwg.org/#parse-error-missing-end-tag-name
*/
if ( '>' === $html[ $at + 1 ] ) {
$this->parser_state = self::STATE_PRESUMPTUOUS_TAG;
$this->token_length = $at + 2 - $this->token_starts_at;
$this->bytes_already_parsed = $at + 2;
return true;
}
/*
* `<?` transitions to a bogus comment state – skip to the nearest >
* See https://html.spec.whatwg.org/multipage/parsing.html#tag-open-state
*/
if ( '?' === $html[ $at + 1 ] ) {
$closer_at = strpos( $html, '>', $at + 2 );
if ( false === $closer_at ) {
$this->parser_state = self::STATE_INCOMPLETE_INPUT;
return false;
}
$this->parser_state = self::STATE_COMMENT;
$this->comment_type = self::COMMENT_AS_INVALID_HTML;
$this->token_length = $closer_at + 1 - $this->token_starts_at;
$this->text_starts_at = $this->token_starts_at + 2;
$this->text_length = $closer_at - $this->text_starts_at;
$this->bytes_already_parsed = $closer_at + 1;
/*
* Identify a Processing Instruction node were HTML to have them.
*
* This section must occur after identifying the bogus comment end
* because in an HTML parser it will span to the nearest `>`, even
* if there's no `?>` as would be required in an XML document. It
* is therefore not possible to parse a Processing Instruction node
* containing a `>` in the HTML syntax.
*
* XML allows for more target names, but this code only identifies
* those with ASCII-representable target names. This means that it
* may identify some Processing Instruction nodes as bogus comments,
* but it will not misinterpret the HTML structure. By limiting the
* identification to these target names the Tag Processor can avoid
* the need to start parsing UTF-8 sequences.
*
* > NameStartChar ::= ":" | [A-Z] | "_" | [a-z] | [#xC0-#xD6] | [#xD8-#xF6] | [#xF8-#x2FF] |
* [#x370-#x37D] | [#x37F-#x1FFF] | [#x200C-#x200D] | [#x2070-#x218F] |
* [#x2C00-#x2FEF] | [#x3001-#xD7FF] | [#xF900-#xFDCF] | [#xFDF0-#xFFFD] |
* [#x10000-#xEFFFF]
* > NameChar ::= NameStartChar | "-" | "." | [0-9] | #xB7 | [#x0300-#x036F] | [#x203F-#x2040]
*
* @see https://www.w3.org/TR/2006/REC-xml11-20060816/#NT-PITarget
*/
if ( $this->token_length >= 5 && '?' === $html[ $closer_at - 1 ] ) {
$comment_text = substr( $html, $this->token_starts_at + 2, $this->token_length - 4 );
$pi_target_length = strspn( $comment_text, 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ:_' );
if ( 0 < $pi_target_length ) {
$pi_target_length += strspn( $comment_text, 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789:_-.', $pi_target_length );
$this->comment_type = self::COMMENT_AS_PI_NODE_LOOKALIKE;
$this->tag_name_starts_at = $this->token_starts_at + 2;
$this->tag_name_length = $pi_target_length;
$this->text_starts_at += $pi_target_length;
$this->text_length -= $pi_target_length + 1;
}
}
return true;
}
/*
* If a non-alpha starts the tag name in a tag closer it's a comment.
* Find the first `>`, which closes the comment.
*
* This parser classifies these particular comments as special "funky comments"
* which are made available for further processing.
*
* See https://html.spec.whatwg.org/#parse-error-invalid-first-character-of-tag-name
*/
if ( $this->is_closing_tag ) {
// No chance of finding a closer.
if ( $at + 3 > $doc_length ) {
return false;
}
$closer_at = strpos( $html, '>', $at + 3 );
if ( false === $closer_at ) {
$this->parser_state = self::STATE_INCOMPLETE_INPUT;
return false;
}
$this->parser_state = self::STATE_FUNKY_COMMENT;
$this->token_length = $closer_at + 1 - $this->token_starts_at;
$this->text_starts_at = $this->token_starts_at + 2;
$this->text_length = $closer_at - $this->text_starts_at;
$this->bytes_already_parsed = $closer_at + 1;
return true;
}
++$at;
}
return false;
}
/**
* Parses the next attribute.
*
* @since 6.2.0
*
* @return bool Whether an attribute was found before the end of the document.
*/
private function parse_next_attribute() {
// Skip whitespace and slashes.
$this->bytes_already_parsed += strspn( $this->html, " \t\f\r\n/", $this->bytes_already_parsed );
if ( $this->bytes_already_parsed >= strlen( $this->html ) ) {
$this->parser_state = self::STATE_INCOMPLETE_INPUT;
return false;
}
/*
* Treat the equal sign as a part of the attribute
* name if it is the first encountered byte.
*
* @see https://html.spec.whatwg.org/multipage/parsing.html#before-attribute-name-state
*/
$name_length = '=' === $this->html[ $this->bytes_already_parsed ]
? 1 + strcspn( $this->html, "=/> \t\f\r\n", $this->bytes_already_parsed + 1 )
: strcspn( $this->html, "=/> \t\f\r\n", $this->bytes_already_parsed );
// No attribute, just tag closer.
if ( 0 === $name_length || $this->bytes_already_parsed + $name_length >= strlen( $this->html ) ) {
return false;
}
$attribute_start = $this->bytes_already_parsed;
$attribute_name = substr( $this->html, $attribute_start, $name_length );
$this->bytes_already_parsed += $name_length;
if ( $this->bytes_already_parsed >= strlen( $this->html ) ) {
$this->parser_state = self::STATE_INCOMPLETE_INPUT;
return false;
}
$this->skip_whitespace();
if ( $this->bytes_already_parsed >= strlen( $this->html ) ) {
$this->parser_state = self::STATE_INCOMPLETE_INPUT;
return false;
}
$has_value = '=' === $this->html[ $this->bytes_already_parsed ];
if ( $has_value ) {
++$this->bytes_already_parsed;
$this->skip_whitespace();
if ( $this->bytes_already_parsed >= strlen( $this->html ) ) {
$this->parser_state = self::STATE_INCOMPLETE_INPUT;
return false;
}
switch ( $this->html[ $this->bytes_already_parsed ] ) {
case "'":
case '"':
$quote = $this->html[ $this->bytes_already_parsed ];
$value_start = $this->bytes_already_parsed + 1;
$value_length = strcspn( $this->html, $quote, $value_start );
$attribute_end = $value_start + $value_length + 1;
$this->bytes_already_parsed = $attribute_end;
break;
default:
$value_start = $this->bytes_already_parsed;
$value_length = strcspn( $this->html, "> \t\f\r\n", $value_start );
$attribute_end = $value_start + $value_length;
$this->bytes_already_parsed = $attribute_end;
}
} else {
$value_start = $this->bytes_already_parsed;
$value_length = 0;
$attribute_end = $attribute_start + $name_length;
}
if ( $attribute_end >= strlen( $this->html ) ) {
$this->parser_state = self::STATE_INCOMPLETE_INPUT;
return false;
}
if ( $this->is_closing_tag ) {
return true;
}
/*
* > There must never be two or more attributes on
* > the same start tag whose names are an ASCII
* > case-insensitive match for each other.
* - HTML 5 spec
*
* @see https://html.spec.whatwg.org/multipage/syntax.html#attributes-2:ascii-case-insensitive
*/
$comparable_name = strtolower( $attribute_name );
// If an attribute is listed many times, only use the first declaration and ignore the rest.
if ( ! array_key_exists( $comparable_name, $this->attributes ) ) {
$this->attributes[ $comparable_name ] = new WP_HTML_Attribute_Token(
$attribute_name,
$value_start,
$value_length,
$attribute_start,
$attribute_end - $attribute_start,
! $has_value
);
return true;
}
/*
* Track the duplicate attributes so if we remove it, all disappear together.
*
* While `$this->duplicated_attributes` could always be stored as an `array()`,
* which would simplify the logic here, storing a `null` and only allocating
* an array when encountering duplicates avoids needless allocations in the
* normative case of parsing tags with no duplicate attributes.
*/
$duplicate_span = new WP_HTML_Span( $attribute_start, $attribute_end - $attribute_start );
if ( null === $this->duplicate_attributes ) {
$this->duplicate_attributes = array( $comparable_name => array( $duplicate_span ) );
} elseif ( ! array_key_exists( $comparable_name, $this->duplicate_attributes ) ) {
$this->duplicate_attributes[ $comparable_name ] = array( $duplicate_span );
} else {
$this->duplicate_attributes[ $comparable_name ][] = $duplicate_span;
}
return true;
}
/**
* Move the internal cursor past any immediate successive whitespace.
*
* @since 6.2.0
*/
private function skip_whitespace() {
$this->bytes_already_parsed += strspn( $this->html, " \t\f\r\n", $this->bytes_already_parsed );
}
/**
* Applies attribute updates and cleans up once a tag is fully parsed.
*
* @since 6.2.0
*/
private function after_tag() {
/*
* There could be lexical updates enqueued for an attribute that
* also exists on the next tag. In order to avoid conflating the
* attributes across the two tags, lexical updates with names
* need to be flushed to raw lexical updates.
*/
$this->class_name_updates_to_attributes_updates();
/*
* Purge updates if there are too many. The actual count isn't
* scientific, but a few values from 100 to a few thousand were
* tests to find a practially-useful limit.
*
* If the update queue grows too big, then the Tag Processor
* will spend more time iterating through them and lose the
* efficiency gains of deferring applying them.
*/
if ( 1000 < count( $this->lexical_updates ) ) {
$this->get_updated_html();
}
foreach ( $this->lexical_updates as $name => $update ) {
/*
* Any updates appearing after the cursor should be applied
* before proceeding, otherwise they may be overlooked.
*/
if ( $update->start >= $this->bytes_already_parsed ) {
$this->get_updated_html();
break;
}
if ( is_int( $name ) ) {
continue;
}
$this->lexical_updates[] = $update;
unset( $this->lexical_updates[ $name ] );
}
$this->token_starts_at = null;
$this->token_length = null;
$this->tag_name_starts_at = null;
$this->tag_name_length = null;
$this->text_starts_at = 0;
$this->text_length = 0;
$this->is_closing_tag = null;
$this->attributes = array();
$this->comment_type = null;
$this->duplicate_attributes = null;
}
/**
* Converts class name updates into tag attributes updates
* (they are accumulated in different data formats for performance).
*
* @since 6.2.0
*
* @see WP_HTML_Tag_Processor::$lexical_updates
* @see WP_HTML_Tag_Processor::$classname_updates
*/
private function class_name_updates_to_attributes_updates() {
if ( count( $this->classname_updates ) === 0 ) {
return;
}
$existing_class = $this->get_enqueued_attribute_value( 'class' );
if ( null === $existing_class || true === $existing_class ) {
$existing_class = '';
}
if ( false === $existing_class && isset( $this->attributes['class'] ) ) {
$existing_class = substr(
$this->html,
$this->attributes['class']->value_starts_at,
$this->attributes['class']->value_length
);
}
if ( false === $existing_class ) {
$existing_class = '';
}
/**
* Updated "class" attribute value.
*
* This is incrementally built while scanning through the existing class
* attribute, skipping removed classes on the way, and then appending
* added classes at the end. Only when finished processing will the
* value contain the final new value.
* @var string $class
*/
$class = '';
/**
* Tracks the cursor position in the existing
* class attribute value while parsing.
*
* @var int $at
*/
$at = 0;
/**
* Indicates if there's any need to modify the existing class attribute.
*
* If a call to `add_class()` and `remove_class()` wouldn't impact
* the `class` attribute value then there's no need to rebuild it.
* For example, when adding a class that's already present or
* removing one that isn't.
*
* This flag enables a performance optimization when none of the enqueued
* class updates would impact the `class` attribute; namely, that the
* processor can continue without modifying the input document, as if
* none of the `add_class()` or `remove_class()` calls had been made.
*
* This flag is set upon the first change that requires a string update.
*
* @var bool $modified
*/
$modified = false;
// Remove unwanted classes by only copying the new ones.
$existing_class_length = strlen( $existing_class );
while ( $at < $existing_class_length ) {
// Skip to the first non-whitespace character.
$ws_at = $at;
$ws_length = strspn( $existing_class, " \t\f\r\n", $ws_at );
$at += $ws_length;
// Capture the class name – it's everything until the next whitespace.
$name_length = strcspn( $existing_class, " \t\f\r\n", $at );
if ( 0 === $name_length ) {
// If no more class names are found then that's the end.
break;
}
$name = substr( $existing_class, $at, $name_length );
$at += $name_length;
// If this class is marked for removal, start processing the next one.
$remove_class = (
isset( $this->classname_updates[ $name ] ) &&
self::REMOVE_CLASS === $this->classname_updates[ $name ]
);
// If a class has already been seen then skip it; it should not be added twice.
if ( ! $remove_class ) {
$this->classname_updates[ $name ] = self::SKIP_CLASS;
}
if ( $remove_class ) {
$modified = true;
continue;
}
/*
* Otherwise, append it to the new "class" attribute value.
*
* There are options for handling whitespace between tags.
* Preserving the existing whitespace produces fewer changes
* to the HTML content and should clarify the before/after
* content when debugging the modified output.
*
* This approach contrasts normalizing the inter-class
* whitespace to a single space, which might appear cleaner
* in the output HTML but produce a noisier change.
*/
$class .= substr( $existing_class, $ws_at, $ws_length );
$class .= $name;
}
// Add new classes by appending those which haven't already been seen.
foreach ( $this->classname_updates as $name => $operation ) {
if ( self::ADD_CLASS === $operation ) {
$modified = true;
$class .= strlen( $class ) > 0 ? ' ' : '';
$class .= $name;
}
}
$this->classname_updates = array();
if ( ! $modified ) {
return;
}
if ( strlen( $class ) > 0 ) {
$this->set_attribute( 'class', $class );
} else {
$this->remove_attribute( 'class' );
}
}
/**
* Applies attribute updates to HTML document.
*
* @since 6.2.0
* @since 6.2.1 Accumulates shift for internal cursor and passed pointer.
* @since 6.3.0 Invalidate any bookmarks whose targets are overwritten.
*
* @param int $shift_this_point Accumulate and return shift for this position.
* @return int How many bytes the given pointer moved in response to the updates.
*/
private function apply_attributes_updates( $shift_this_point = 0 ) {
if ( ! count( $this->lexical_updates ) ) {
return 0;
}
$accumulated_shift_for_given_point = 0;
/*
* Attribute updates can be enqueued in any order but updates
* to the document must occur in lexical order; that is, each
* replacement must be made before all others which follow it
* at later string indices in the input document.
*
* Sorting avoid making out-of-order replacements which
* can lead to mangled output, partially-duplicated
* attributes, and overwritten attributes.
*/
usort( $this->lexical_updates, array( self::class, 'sort_start_ascending' ) );
$bytes_already_copied = 0;
$output_buffer = '';
foreach ( $this->lexical_updates as $diff ) {
$shift = strlen( $diff->text ) - $diff->length;
// Adjust the cursor position by however much an update affects it.
if ( $diff->start < $this->bytes_already_parsed ) {
$this->bytes_already_parsed += $shift;
}
// Accumulate shift of the given pointer within this function call.
if ( $diff->start <= $shift_this_point ) {
$accumulated_shift_for_given_point += $shift;
}
$output_buffer .= substr( $this->html, $bytes_already_copied, $diff->start - $bytes_already_copied );
$output_buffer .= $diff->text;
$bytes_already_copied = $diff->start + $diff->length;
}
$this->html = $output_buffer . substr( $this->html, $bytes_already_copied );
/*
* Adjust bookmark locations to account for how the text
* replacements adjust offsets in the input document.
*/
foreach ( $this->bookmarks as $bookmark_name => $bookmark ) {
$bookmark_end = $bookmark->start + $bookmark->length;
/*
* Each lexical update which appears before the bookmark's endpoints
* might shift the offsets for those endpoints. Loop through each change
* and accumulate the total shift for each bookmark, then apply that
* shift after tallying the full delta.
*/
$head_delta = 0;
$tail_delta = 0;
foreach ( $this->lexical_updates as $diff ) {
$diff_end = $diff->start + $diff->length;
if ( $bookmark->start < $diff->start && $bookmark_end < $diff->start ) {
break;
}
if ( $bookmark->start >= $diff->start && $bookmark_end < $diff_end ) {
$this->release_bookmark( $bookmark_name );
continue 2;
}
$delta = strlen( $diff->text ) - $diff->length;
if ( $bookmark->start >= $diff->start ) {
$head_delta += $delta;
}
if ( $bookmark_end >= $diff_end ) {
$tail_delta += $delta;
}
}
$bookmark->start += $head_delta;
$bookmark->length += $tail_delta - $head_delta;
}
$this->lexical_updates = array();
return $accumulated_shift_for_given_point;
}
/**
* Checks whether a bookmark with the given name exists.
*
* @since 6.3.0
*
* @param string $bookmark_name Name to identify a bookmark that potentially exists.
* @return bool Whether that bookmark exists.
*/
public function has_bookmark( $bookmark_name ) {
return array_key_exists( $bookmark_name, $this->bookmarks );
}
/**
* Move the internal cursor in the Tag Processor to a given bookmark's location.
*
* In order to prevent accidental infinite loops, there's a
* maximum limit on the number of times seek() can be called.
*
* @since 6.2.0
*
* @param string $bookmark_name Jump to the place in the document identified by this bookmark name.
* @return bool Whether the internal cursor was successfully moved to the bookmark's location.
*/
public function seek( $bookmark_name ) {
if ( ! array_key_exists( $bookmark_name, $this->bookmarks ) ) {
_doing_it_wrong(
__METHOD__,
__( 'Unknown bookmark name.' ),
'6.2.0'
);
return false;
}
if ( ++$this->seek_count > static::MAX_SEEK_OPS ) {
_doing_it_wrong(
__METHOD__,
__( 'Too many calls to seek() - this can lead to performance issues.' ),
'6.2.0'
);
return false;
}
// Flush out any pending updates to the document.
$this->get_updated_html();
// Point this tag processor before the sought tag opener and consume it.
$this->bytes_already_parsed = $this->bookmarks[ $bookmark_name ]->start;
$this->parser_state = self::STATE_READY;
return $this->next_token();
}
/**
* Compare two WP_HTML_Text_Replacement objects.
*
* @since 6.2.0
*
* @param WP_HTML_Text_Replacement $a First attribute update.
* @param WP_HTML_Text_Replacement $b Second attribute update.
* @return int Comparison value for string order.
*/
private static function sort_start_ascending( $a, $b ) {
$by_start = $a->start - $b->start;
if ( 0 !== $by_start ) {
return $by_start;
}
$by_text = isset( $a->text, $b->text ) ? strcmp( $a->text, $b->text ) : 0;
if ( 0 !== $by_text ) {
return $by_text;
}
/*
* This code should be unreachable, because it implies the two replacements
* start at the same location and contain the same text.
*/
return $a->length - $b->length;
}
/**
* Return the enqueued value for a given attribute, if one exists.
*
* Enqueued updates can take different data types:
* - If an update is enqueued and is boolean, the return will be `true`
* - If an update is otherwise enqueued, the return will be the string value of that update.
* - If an attribute is enqueued to be removed, the return will be `null` to indicate that.
* - If no updates are enqueued, the return will be `false` to differentiate from "removed."
*
* @since 6.2.0
*
* @param string $comparable_name The attribute name in its comparable form.
* @return string|boolean|null Value of enqueued update if present, otherwise false.
*/
private function get_enqueued_attribute_value( $comparable_name ) {
if ( self::STATE_MATCHED_TAG !== $this->parser_state ) {
return false;
}
if ( ! isset( $this->lexical_updates[ $comparable_name ] ) ) {
return false;
}
$enqueued_text = $this->lexical_updates[ $comparable_name ]->text;
// Removed attributes erase the entire span.
if ( '' === $enqueued_text ) {
return null;
}
/*
* Boolean attribute updates are just the attribute name without a corresponding value.
*
* This value might differ from the given comparable name in that there could be leading
* or trailing whitespace, and that the casing follows the name given in `set_attribute`.
*
* Example:
*
* $p->set_attribute( 'data-TEST-id', 'update' );
* 'update' === $p->get_enqueued_attribute_value( 'data-test-id' );
*
* Detect this difference based on the absence of the `=`, which _must_ exist in any
* attribute containing a value, e.g. `<input type="text" enabled />`.
* ¹ ²
* 1. Attribute with a string value.
* 2. Boolean attribute whose value is `true`.
*/
$equals_at = strpos( $enqueued_text, '=' );
if ( false === $equals_at ) {
return true;
}
/*
* Finally, a normal update's value will appear after the `=` and
* be double-quoted, as performed incidentally by `set_attribute`.
*
* e.g. `type="text"`
* ¹² ³
* 1. Equals is here.
* 2. Double-quoting starts one after the equals sign.
* 3. Double-quoting ends at the last character in the update.
*/
$enqueued_value = substr( $enqueued_text, $equals_at + 2, -1 );
return html_entity_decode( $enqueued_value );
}
/**
* Returns the value of a requested attribute from a matched tag opener if that attribute exists.
*
* Example:
*
* $p = new WP_HTML_Tag_Processor( '<div enabled class="test" data-test-id="14">Test</div>' );
* $p->next_tag( array( 'class_name' => 'test' ) ) === true;
* $p->get_attribute( 'data-test-id' ) === '14';
* $p->get_attribute( 'enabled' ) === true;
* $p->get_attribute( 'aria-label' ) === null;
*
* $p->next_tag() === false;
* $p->get_attribute( 'class' ) === null;
*
* @since 6.2.0
*
* @param string $name Name of attribute whose value is requested.
* @return string|true|null Value of attribute or `null` if not available. Boolean attributes return `true`.
*/
public function get_attribute( $name ) {
if ( self::STATE_MATCHED_TAG !== $this->parser_state ) {
return null;
}
$comparable = strtolower( $name );
/*
* For every attribute other than `class` it's possible to perform a quick check if
* there's an enqueued lexical update whose value takes priority over what's found in
* the input document.
*
* The `class` attribute is special though because of the exposed helpers `add_class`
* and `remove_class`. These form a builder for the `class` attribute, so an additional
* check for enqueued class changes is required in addition to the check for any enqueued
* attribute values. If any exist, those enqueued class changes must first be flushed out
* into an attribute value update.
*/
if ( 'class' === $name ) {
$this->class_name_updates_to_attributes_updates();
}
// Return any enqueued attribute value updates if they exist.
$enqueued_value = $this->get_enqueued_attribute_value( $comparable );
if ( false !== $enqueued_value ) {
return $enqueued_value;
}
if ( ! isset( $this->attributes[ $comparable ] ) ) {
return null;
}
$attribute = $this->attributes[ $comparable ];
/*
* This flag distinguishes an attribute with no value
* from an attribute with an empty string value. For
* unquoted attributes this could look very similar.
* It refers to whether an `=` follows the name.
*
* e.g. <div boolean-attribute empty-attribute=></div>
* ¹ ²
* 1. Attribute `boolean-attribute` is `true`.
* 2. Attribute `empty-attribute` is `""`.
*/
if ( true === $attribute->is_true ) {
return true;
}
$raw_value = substr( $this->html, $attribute->value_starts_at, $attribute->value_length );
return html_entity_decode( $raw_value );
}
/**
* Gets lowercase names of all attributes matching a given prefix in the current tag.
*
* Note that matching is case-insensitive. This is in accordance with the spec:
*
* > There must never be two or more attributes on
* > the same start tag whose names are an ASCII
* > case-insensitive match for each other.
* - HTML 5 spec
*
* Example:
*
* $p = new WP_HTML_Tag_Processor( '<div data-ENABLED class="test" DATA-test-id="14">Test</div>' );
* $p->next_tag( array( 'class_name' => 'test' ) ) === true;
* $p->get_attribute_names_with_prefix( 'data-' ) === array( 'data-enabled', 'data-test-id' );
*
* $p->next_tag() === false;
* $p->get_attribute_names_with_prefix( 'data-' ) === null;
*
* @since 6.2.0
*
* @see https://html.spec.whatwg.org/multipage/syntax.html#attributes-2:ascii-case-insensitive
*
* @param string $prefix Prefix of requested attribute names.
* @return array|null List of attribute names, or `null` when no tag opener is matched.
*/
public function get_attribute_names_with_prefix( $prefix ) {
if (
self::STATE_MATCHED_TAG !== $this->parser_state ||
$this->is_closing_tag
) {
return null;
}
$comparable = strtolower( $prefix );
$matches = array();
foreach ( array_keys( $this->attributes ) as $attr_name ) {
if ( str_starts_with( $attr_name, $comparable ) ) {
$matches[] = $attr_name;
}
}
return $matches;
}
/**
* Returns the uppercase name of the matched tag.
*
* Example:
*
* $p = new WP_HTML_Tag_Processor( '<div class="test">Test</div>' );
* $p->next_tag() === true;
* $p->get_tag() === 'DIV';
*
* $p->next_tag() === false;
* $p->get_tag() === null;
*
* @since 6.2.0
*
* @return string|null Name of currently matched tag in input HTML, or `null` if none found.
*/
public function get_tag() {
if ( null === $this->tag_name_starts_at ) {
return null;
}
$tag_name = substr( $this->html, $this->tag_name_starts_at, $this->tag_name_length );
if ( self::STATE_MATCHED_TAG === $this->parser_state ) {
return strtoupper( $tag_name );
}
if (
self::STATE_COMMENT === $this->parser_state &&
self::COMMENT_AS_PI_NODE_LOOKALIKE === $this->get_comment_type()
) {
return $tag_name;
}
return null;
}
/**
* Indicates if the currently matched tag contains the self-closing flag.
*
* No HTML elements ought to have the self-closing flag and for those, the self-closing
* flag will be ignored. For void elements this is benign because they "self close"
* automatically. For non-void HTML elements though problems will appear if someone
* intends to use a self-closing element in place of that element with an empty body.
* For HTML foreign elements and custom elements the self-closing flag determines if
* they self-close or not.
*
* This function does not determine if a tag is self-closing,
* but only if the self-closing flag is present in the syntax.
*
* @since 6.3.0
*
* @return bool Whether the currently matched tag contains the self-closing flag.
*/
public function has_self_closing_flag() {
if ( self::STATE_MATCHED_TAG !== $this->parser_state ) {
return false;
}
/*
* The self-closing flag is the solidus at the _end_ of the tag, not the beginning.
*
* Example:
*
* <figure />
* ^ this appears one character before the end of the closing ">".
*/
return '/' === $this->html[ $this->token_starts_at + $this->token_length - 1 ];
}
/**
* Indicates if the current tag token is a tag closer.
*
* Example:
*
* $p = new WP_HTML_Tag_Processor( '<div></div>' );
* $p->next_tag( array( 'tag_name' => 'div', 'tag_closers' => 'visit' ) );
* $p->is_tag_closer() === false;
*
* $p->next_tag( array( 'tag_name' => 'div', 'tag_closers' => 'visit' ) );
* $p->is_tag_closer() === true;
*
* @since 6.2.0
*
* @return bool Whether the current tag is a tag closer.
*/
public function is_tag_closer() {
return (
self::STATE_MATCHED_TAG === $this->parser_state &&
$this->is_closing_tag
);
}
/**
* Indicates the kind of matched token, if any.
*
* This differs from `get_token_name()` in that it always
* returns a static string indicating the type, whereas
* `get_token_name()` may return values derived from the
* token itself, such as a tag name or processing
* instruction tag.
*
* Possible values:
* - `#tag` when matched on a tag.
* - `#text` when matched on a text node.
* - `#cdata-section` when matched on a CDATA node.
* - `#comment` when matched on a comment.
* - `#doctype` when matched on a DOCTYPE declaration.
* - `#presumptuous-tag` when matched on an empty tag closer.
* - `#funky-comment` when matched on a funky comment.
*
* @since 6.5.0
*
* @return string|null What kind of token is matched, or null.
*/
public function get_token_type() {
switch ( $this->parser_state ) {
case self::STATE_MATCHED_TAG:
return '#tag';
case self::STATE_DOCTYPE:
return '#doctype';
default:
return $this->get_token_name();
}
}
/**
* Returns the node name represented by the token.
*
* This matches the DOM API value `nodeName`. Some values
* are static, such as `#text` for a text node, while others
* are dynamically generated from the token itself.
*
* Dynamic names:
* - Uppercase tag name for tag matches.
* - `html` for DOCTYPE declarations.
*
* Note that if the Tag Processor is not matched on a token
* then this function will return `null`, either because it
* hasn't yet found a token or because it reached the end
* of the document without matching a token.
*
* @since 6.5.0
*
* @return string|null Name of the matched token.
*/
public function get_token_name() {
switch ( $this->parser_state ) {
case self::STATE_MATCHED_TAG:
return $this->get_tag();
case self::STATE_TEXT_NODE:
return '#text';
case self::STATE_CDATA_NODE:
return '#cdata-section';
case self::STATE_COMMENT:
return '#comment';
case self::STATE_DOCTYPE:
return 'html';
case self::STATE_PRESUMPTUOUS_TAG:
return '#presumptuous-tag';
case self::STATE_FUNKY_COMMENT:
return '#funky-comment';
}
}
/**
* Indicates what kind of comment produced the comment node.
*
* Because there are different kinds of HTML syntax which produce
* comments, the Tag Processor tracks and exposes this as a type
* for the comment. Nominally only regular HTML comments exist as
* they are commonly known, but a number of unrelated syntax errors
* also produce comments.
*
* @see self::COMMENT_AS_ABRUPTLY_CLOSED_COMMENT
* @see self::COMMENT_AS_CDATA_LOOKALIKE
* @see self::COMMENT_AS_INVALID_HTML
* @see self::COMMENT_AS_HTML_COMMENT
* @see self::COMMENT_AS_PI_NODE_LOOKALIKE
*
* @since 6.5.0
*
* @return string|null
*/
public function get_comment_type() {
if ( self::STATE_COMMENT !== $this->parser_state ) {
return null;
}
return $this->comment_type;
}
/**
* Returns the modifiable text for a matched token, or an empty string.
*
* Modifiable text is text content that may be read and changed without
* changing the HTML structure of the document around it. This includes
* the contents of `#text` nodes in the HTML as well as the inner
* contents of HTML comments, Processing Instructions, and others, even
* though these nodes aren't part of a parsed DOM tree. They also contain
* the contents of SCRIPT and STYLE tags, of TEXTAREA tags, and of any
* other section in an HTML document which cannot contain HTML markup (DATA).
*
* If a token has no modifiable text then an empty string is returned to
* avoid needless crashing or type errors. An empty string does not mean
* that a token has modifiable text, and a token with modifiable text may
* have an empty string (e.g. a comment with no contents).
*
* @since 6.5.0
*
* @return string
*/
public function get_modifiable_text() {
if ( null === $this->text_starts_at ) {
return '';
}
$text = substr( $this->html, $this->text_starts_at, $this->text_length );
// Comment data is not decoded.
if (
self::STATE_CDATA_NODE === $this->parser_state ||
self::STATE_COMMENT === $this->parser_state ||
self::STATE_DOCTYPE === $this->parser_state ||
self::STATE_FUNKY_COMMENT === $this->parser_state
) {
return $text;
}
$tag_name = $this->get_tag();
if (
// Script data is not decoded.
'SCRIPT' === $tag_name ||
// RAWTEXT data is not decoded.
'IFRAME' === $tag_name ||
'NOEMBED' === $tag_name ||
'NOFRAMES' === $tag_name ||
'STYLE' === $tag_name ||
'XMP' === $tag_name
) {
return $text;
}
$decoded = html_entity_decode( $text, ENT_QUOTES | ENT_HTML5 | ENT_SUBSTITUTE );
/*
* TEXTAREA skips a leading newline, but this newline may appear not only as the
* literal character `\n`, but also as a character reference, such as in the
* following markup: `<textarea>
Content</textarea>`.
*
* For these cases it's important to first decode the text content before checking
* for a leading newline and removing it.
*/
if (
self::STATE_MATCHED_TAG === $this->parser_state &&
'TEXTAREA' === $tag_name &&
strlen( $decoded ) > 0 &&
"\n" === $decoded[0]
) {
return substr( $decoded, 1 );
}
return $decoded;
}
/**
* Updates or creates a new attribute on the currently matched tag with the passed value.
*
* For boolean attributes special handling is provided:
* - When `true` is passed as the value, then only the attribute name is added to the tag.
* - When `false` is passed, the attribute gets removed if it existed before.
*
* For string attributes, the value is escaped using the `esc_attr` function.
*
* @since 6.2.0
* @since 6.2.1 Fix: Only create a single update for multiple calls with case-variant attribute names.
*
* @param string $name The attribute name to target.
* @param string|bool $value The new attribute value.
* @return bool Whether an attribute value was set.
*/
public function set_attribute( $name, $value ) {
if (
self::STATE_MATCHED_TAG !== $this->parser_state ||
$this->is_closing_tag
) {
return false;
}
/*
* WordPress rejects more characters than are strictly forbidden
* in HTML5. This is to prevent additional security risks deeper
* in the WordPress and plugin stack. Specifically the
* less-than (<) greater-than (>) and ampersand (&) aren't allowed.
*
* The use of a PCRE match enables looking for specific Unicode
* code points without writing a UTF-8 decoder. Whereas scanning
* for one-byte characters is trivial (with `strcspn`), scanning
* for the longer byte sequences would be more complicated. Given
* that this shouldn't be in the hot path for execution, it's a
* reasonable compromise in efficiency without introducing a
* noticeable impact on the overall system.
*
* @see https://html.spec.whatwg.org/#attributes-2
*
* @todo As the only regex pattern maybe we should take it out?
* Are Unicode patterns available broadly in Core?
*/
if ( preg_match(
'~[' .
// Syntax-like characters.
'"\'>&</ =' .
// Control characters.
'\x{00}-\x{1F}' .
// HTML noncharacters.
'\x{FDD0}-\x{FDEF}' .
'\x{FFFE}\x{FFFF}\x{1FFFE}\x{1FFFF}\x{2FFFE}\x{2FFFF}\x{3FFFE}\x{3FFFF}' .
'\x{4FFFE}\x{4FFFF}\x{5FFFE}\x{5FFFF}\x{6FFFE}\x{6FFFF}\x{7FFFE}\x{7FFFF}' .
'\x{8FFFE}\x{8FFFF}\x{9FFFE}\x{9FFFF}\x{AFFFE}\x{AFFFF}\x{BFFFE}\x{BFFFF}' .
'\x{CFFFE}\x{CFFFF}\x{DFFFE}\x{DFFFF}\x{EFFFE}\x{EFFFF}\x{FFFFE}\x{FFFFF}' .
'\x{10FFFE}\x{10FFFF}' .
']~Ssu',
$name
) ) {
_doing_it_wrong(
__METHOD__,
__( 'Invalid attribute name.' ),
'6.2.0'
);
return false;
}
/*
* > The values "true" and "false" are not allowed on boolean attributes.
* > To represent a false value, the attribute has to be omitted altogether.
* - HTML5 spec, https://html.spec.whatwg.org/#boolean-attributes
*/
if ( false === $value ) {
return $this->remove_attribute( $name );
}
if ( true === $value ) {
$updated_attribute = $name;
} else {
$comparable_name = strtolower( $name );
/*
* Escape URL attributes.
*
* @see https://html.spec.whatwg.org/#attributes-3
*/
$escaped_new_value = in_array( $comparable_name, wp_kses_uri_attributes() ) ? esc_url( $value ) : esc_attr( $value );
$updated_attribute = "{$name}=\"{$escaped_new_value}\"";
}
/*
* > There must never be two or more attributes on
* > the same start tag whose names are an ASCII
* > case-insensitive match for each other.
* - HTML 5 spec
*
* @see https://html.spec.whatwg.org/multipage/syntax.html#attributes-2:ascii-case-insensitive
*/
$comparable_name = strtolower( $name );
if ( isset( $this->attributes[ $comparable_name ] ) ) {
/*
* Update an existing attribute.
*
* Example – set attribute id to "new" in <div id="initial_id" />:
*
* <div id="initial_id"/>
* ^-------------^
* start end
* replacement: `id="new"`
*
* Result: <div id="new"/>
*/
$existing_attribute = $this->attributes[ $comparable_name ];
$this->lexical_updates[ $comparable_name ] = new WP_HTML_Text_Replacement(
$existing_attribute->start,
$existing_attribute->length,
$updated_attribute
);
} else {
/*
* Create a new attribute at the tag's name end.
*
* Example – add attribute id="new" to <div />:
*
* <div/>
* ^
* start and end
* replacement: ` id="new"`
*
* Result: <div id="new"/>
*/
$this->lexical_updates[ $comparable_name ] = new WP_HTML_Text_Replacement(
$this->tag_name_starts_at + $this->tag_name_length,
0,
' ' . $updated_attribute
);
}
/*
* Any calls to update the `class` attribute directly should wipe out any
* enqueued class changes from `add_class` and `remove_class`.
*/
if ( 'class' === $comparable_name && ! empty( $this->classname_updates ) ) {
$this->classname_updates = array();
}
return true;
}
/**
* Remove an attribute from the currently-matched tag.
*
* @since 6.2.0
*
* @param string $name The attribute name to remove.
* @return bool Whether an attribute was removed.
*/
public function remove_attribute( $name ) {
if (
self::STATE_MATCHED_TAG !== $this->parser_state ||
$this->is_closing_tag
) {
return false;
}
/*
* > There must never be two or more attributes on
* > the same start tag whose names are an ASCII
* > case-insensitive match for each other.
* - HTML 5 spec
*
* @see https://html.spec.whatwg.org/multipage/syntax.html#attributes-2:ascii-case-insensitive
*/
$name = strtolower( $name );
/*
* Any calls to update the `class` attribute directly should wipe out any
* enqueued class changes from `add_class` and `remove_class`.
*/
if ( 'class' === $name && count( $this->classname_updates ) !== 0 ) {
$this->classname_updates = array();
}
/*
* If updating an attribute that didn't exist in the input
* document, then remove the enqueued update and move on.
*
* For example, this might occur when calling `remove_attribute()`
* after calling `set_attribute()` for the same attribute
* and when that attribute wasn't originally present.
*/
if ( ! isset( $this->attributes[ $name ] ) ) {
if ( isset( $this->lexical_updates[ $name ] ) ) {
unset( $this->lexical_updates[ $name ] );
}
return false;
}
/*
* Removes an existing tag attribute.
*
* Example – remove the attribute id from <div id="main"/>:
* <div id="initial_id"/>
* ^-------------^
* start end
* replacement: ``
*
* Result: <div />
*/
$this->lexical_updates[ $name ] = new WP_HTML_Text_Replacement(
$this->attributes[ $name ]->start,
$this->attributes[ $name ]->length,
''
);
// Removes any duplicated attributes if they were also present.
if ( null !== $this->duplicate_attributes && array_key_exists( $name, $this->duplicate_attributes ) ) {
foreach ( $this->duplicate_attributes[ $name ] as $attribute_token ) {
$this->lexical_updates[] = new WP_HTML_Text_Replacement(
$attribute_token->start,
$attribute_token->length,
''
);
}
}
return true;
}
/**
* Adds a new class name to the currently matched tag.
*
* @since 6.2.0
*
* @param string $class_name The class name to add.
* @return bool Whether the class was set to be added.
*/
public function add_class( $class_name ) {
if (
self::STATE_MATCHED_TAG !== $this->parser_state ||
$this->is_closing_tag
) {
return false;
}
$this->classname_updates[ $class_name ] = self::ADD_CLASS;
return true;
}
/**
* Removes a class name from the currently matched tag.
*
* @since 6.2.0
*
* @param string $class_name The class name to remove.
* @return bool Whether the class was set to be removed.
*/
public function remove_class( $class_name ) {
if (
self::STATE_MATCHED_TAG !== $this->parser_state ||
$this->is_closing_tag
) {
return false;
}
if ( null !== $this->tag_name_starts_at ) {
$this->classname_updates[ $class_name ] = self::REMOVE_CLASS;
}
return true;
}
/**
* Returns the string representation of the HTML Tag Processor.
*
* @since 6.2.0
*
* @see WP_HTML_Tag_Processor::get_updated_html()
*
* @return string The processed HTML.
*/
public function __toString() {
return $this->get_updated_html();
}
/**
* Returns the string representation of the HTML Tag Processor.
*
* @since 6.2.0
* @since 6.2.1 Shifts the internal cursor corresponding to the applied updates.
* @since 6.4.0 No longer calls subclass method `next_tag()` after updating HTML.
*
* @return string The processed HTML.
*/
public function get_updated_html() {
$requires_no_updating = 0 === count( $this->classname_updates ) && 0 === count( $this->lexical_updates );
/*
* When there is nothing more to update and nothing has already been
* updated, return the original document and avoid a string copy.
*/
if ( $requires_no_updating ) {
return $this->html;
}
/*
* Keep track of the position right before the current tag. This will
* be necessary for reparsing the current tag after updating the HTML.
*/
$before_current_tag = $this->token_starts_at;
/*
* 1. Apply the enqueued edits and update all the pointers to reflect those changes.
*/
$this->class_name_updates_to_attributes_updates();
$before_current_tag += $this->apply_attributes_updates( $before_current_tag );
/*
* 2. Rewind to before the current tag and reparse to get updated attributes.
*
* At this point the internal cursor points to the end of the tag name.
* Rewind before the tag name starts so that it's as if the cursor didn't
* move; a call to `next_tag()` will reparse the recently-updated attributes
* and additional calls to modify the attributes will apply at this same
* location, but in order to avoid issues with subclasses that might add
* behaviors to `next_tag()`, the internal methods should be called here
* instead.
*
* It's important to note that in this specific place there will be no change
* because the processor was already at a tag when this was called and it's
* rewinding only to the beginning of this very tag before reprocessing it
* and its attributes.
*
* <p>Previous HTML<em>More HTML</em></p>
* ↑ │ back up by the length of the tag name plus the opening <
* └←─┘ back up by strlen("em") + 1 ==> 3
*/
$this->bytes_already_parsed = $before_current_tag;
$this->base_class_next_token();
return $this->html;
}
/**
* Parses tag query input into internal search criteria.
*
* @since 6.2.0
*
* @param array|string|null $query {
* Optional. Which tag name to find, having which class, etc. Default is to find any tag.
*
* @type string|null $tag_name Which tag to find, or `null` for "any tag."
* @type int|null $match_offset Find the Nth tag matching all search criteria.
* 1 for "first" tag, 3 for "third," etc.
* Defaults to first tag.
* @type string|null $class_name Tag must contain this class name to match.
* @type string $tag_closers "visit" or "skip": whether to stop on tag closers, e.g. </div>.
* }
*/
private function parse_query( $query ) {
if ( null !== $query && $query === $this->last_query ) {
return;
}
$this->last_query = $query;
$this->sought_tag_name = null;
$this->sought_class_name = null;
$this->sought_match_offset = 1;
$this->stop_on_tag_closers = false;
// A single string value means "find the tag of this name".
if ( is_string( $query ) ) {
$this->sought_tag_name = $query;
return;
}
// An empty query parameter applies no restrictions on the search.
if ( null === $query ) {
return;
}
// If not using the string interface, an associative array is required.
if ( ! is_array( $query ) ) {
_doing_it_wrong(
__METHOD__,
__( 'The query argument must be an array or a tag name.' ),
'6.2.0'
);
return;
}
if ( isset( $query['tag_name'] ) && is_string( $query['tag_name'] ) ) {
$this->sought_tag_name = $query['tag_name'];
}
if ( isset( $query['class_name'] ) && is_string( $query['class_name'] ) ) {
$this->sought_class_name = $query['class_name'];
}
if ( isset( $query['match_offset'] ) && is_int( $query['match_offset'] ) && 0 < $query['match_offset'] ) {
$this->sought_match_offset = $query['match_offset'];
}
if ( isset( $query['tag_closers'] ) ) {
$this->stop_on_tag_closers = 'visit' === $query['tag_closers'];
}
}
/**
* Checks whether a given tag and its attributes match the search criteria.
*
* @since 6.2.0
*
* @return bool Whether the given tag and its attribute match the search criteria.
*/
private function matches() {
if ( $this->is_closing_tag && ! $this->stop_on_tag_closers ) {
return false;
}
// Does the tag name match the requested tag name in a case-insensitive manner?
if ( null !== $this->sought_tag_name ) {
/*
* String (byte) length lookup is fast. If they aren't the
* same length then they can't be the same string values.
*/
if ( strlen( $this->sought_tag_name ) !== $this->tag_name_length ) {
return false;
}
/*
* Check each character to determine if they are the same.
* Defer calls to `strtoupper()` to avoid them when possible.
* Calling `strcasecmp()` here tested slowed than comparing each
* character, so unless benchmarks show otherwise, it should
* not be used.
*
* It's expected that most of the time that this runs, a
* lower-case tag name will be supplied and the input will
* contain lower-case tag names, thus normally bypassing
* the case comparison code.
*/
for ( $i = 0; $i < $this->tag_name_length; $i++ ) {
$html_char = $this->html[ $this->tag_name_starts_at + $i ];
$tag_char = $this->sought_tag_name[ $i ];
if ( $html_char !== $tag_char && strtoupper( $html_char ) !== $tag_char ) {
return false;
}
}
}
if ( null !== $this->sought_class_name && ! $this->has_class( $this->sought_class_name ) ) {
return false;
}
return true;
}
/**
* Parser Ready State.
*
* Indicates that the parser is ready to run and waiting for a state transition.
* It may not have started yet, or it may have just finished parsing a token and
* is ready to find the next one.
*
* @since 6.5.0
*
* @access private
*/
const STATE_READY = 'STATE_READY';
/**
* Parser Complete State.
*
* Indicates that the parser has reached the end of the document and there is
* nothing left to scan. It finished parsing the last token completely.
*
* @since 6.5.0
*
* @access private
*/
const STATE_COMPLETE = 'STATE_COMPLETE';
/**
* Parser Incomplete Input State.
*
* Indicates that the parser has reached the end of the document before finishing
* a token. It started parsing a token but there is a possibility that the input
* HTML document was truncated in the middle of a token.
*
* The parser is reset at the start of the incomplete token and has paused. There
* is nothing more than can be scanned unless provided a more complete document.
*
* @since 6.5.0
*
* @access private
*/
const STATE_INCOMPLETE_INPUT = 'STATE_INCOMPLETE_INPUT';
/**
* Parser Matched Tag State.
*
* Indicates that the parser has found an HTML tag and it's possible to get
* the tag name and read or modify its attributes (if it's not a closing tag).
*
* @since 6.5.0
*
* @access private
*/
const STATE_MATCHED_TAG = 'STATE_MATCHED_TAG';
/**
* Parser Text Node State.
*
* Indicates that the parser has found a text node and it's possible
* to read and modify that text.
*
* @since 6.5.0
*
* @access private
*/
const STATE_TEXT_NODE = 'STATE_TEXT_NODE';
/**
* Parser CDATA Node State.
*
* Indicates that the parser has found a CDATA node and it's possible
* to read and modify its modifiable text. Note that in HTML there are
* no CDATA nodes outside of foreign content (SVG and MathML). Outside
* of foreign content, they are treated as HTML comments.
*
* @since 6.5.0
*
* @access private
*/
const STATE_CDATA_NODE = 'STATE_CDATA_NODE';
/**
* Indicates that the parser has found an HTML comment and it's
* possible to read and modify its modifiable text.
*
* @since 6.5.0
*
* @access private
*/
const STATE_COMMENT = 'STATE_COMMENT';
/**
* Indicates that the parser has found a DOCTYPE node and it's
* possible to read and modify its modifiable text.
*
* @since 6.5.0
*
* @access private
*/
const STATE_DOCTYPE = 'STATE_DOCTYPE';
/**
* Indicates that the parser has found an empty tag closer `</>`.
*
* Note that in HTML there are no empty tag closers, and they
* are ignored. Nonetheless, the Tag Processor still
* recognizes them as they appear in the HTML stream.
*
* These were historically discussed as a "presumptuous tag
* closer," which would close the nearest open tag, but were
* dismissed in favor of explicitly-closing tags.
*
* @since 6.5.0
*
* @access private
*/
const STATE_PRESUMPTUOUS_TAG = 'STATE_PRESUMPTUOUS_TAG';
/**
* Indicates that the parser has found a "funky comment"
* and it's possible to read and modify its modifiable text.
*
* Example:
*
* </%url>
* </{"wp-bit":"query/post-author"}>
* </2>
*
* Funky comments are tag closers with invalid tag names. Note
* that in HTML these are turn into bogus comments. Nonetheless,
* the Tag Processor recognizes them in a stream of HTML and
* exposes them for inspection and modification.
*
* @since 6.5.0
*
* @access private
*/
const STATE_FUNKY_COMMENT = 'STATE_WP_FUNKY';
/**
* Indicates that a comment was created when encountering abruptly-closed HTML comment.
*
* Example:
*
* <!-->
* <!--->
*
* @since 6.5.0
*/
const COMMENT_AS_ABRUPTLY_CLOSED_COMMENT = 'COMMENT_AS_ABRUPTLY_CLOSED_COMMENT';
/**
* Indicates that a comment would be parsed as a CDATA node,
* were HTML to allow CDATA nodes outside of foreign content.
*
* Example:
*
* <![CDATA[This is a CDATA node.]]>
*
* This is an HTML comment, but it looks like a CDATA node.
*
* @since 6.5.0
*/
const COMMENT_AS_CDATA_LOOKALIKE = 'COMMENT_AS_CDATA_LOOKALIKE';
/**
* Indicates that a comment was created when encountering
* normative HTML comment syntax.
*
* Example:
*
* <!-- this is a comment -->
*
* @since 6.5.0
*/
const COMMENT_AS_HTML_COMMENT = 'COMMENT_AS_HTML_COMMENT';
/**
* Indicates that a comment would be parsed as a Processing
* Instruction node, were they to exist within HTML.
*
* Example:
*
* <?wp __( 'Like' ) ?>
*
* This is an HTML comment, but it looks like a CDATA node.
*
* @since 6.5.0
*/
const COMMENT_AS_PI_NODE_LOOKALIKE = 'COMMENT_AS_PI_NODE_LOOKALIKE';
/**
* Indicates that a comment was created when encountering invalid
* HTML input, a so-called "bogus comment."
*
* Example:
*
* <?nothing special>
* <!{nothing special}>
*
* @since 6.5.0
*/
const COMMENT_AS_INVALID_HTML = 'COMMENT_AS_INVALID_HTML';
}
class-wp-html-text-replacement.php 0000644 00000002562 15153115200 0013225 0 ustar 00 <?php
/**
* HTML API: WP_HTML_Text_Replacement class
*
* @package WordPress
* @subpackage HTML-API
* @since 6.2.0
*/
/**
* Core class used by the HTML tag processor as a data structure for replacing
* existing content from start to end, allowing to drastically improve performance.
*
* This class is for internal usage of the WP_HTML_Tag_Processor class.
*
* @access private
* @since 6.2.0
* @since 6.5.0 Replace `end` with `length` to more closely match `substr()`.
*
* @see WP_HTML_Tag_Processor
*/
class WP_HTML_Text_Replacement {
/**
* Byte offset into document where replacement span begins.
*
* @since 6.2.0
*
* @var int
*/
public $start;
/**
* Byte length of span being replaced.
*
* @since 6.5.0
*
* @var int
*/
public $length;
/**
* Span of text to insert in document to replace existing content from start to end.
*
* @since 6.2.0
*
* @var string
*/
public $text;
/**
* Constructor.
*
* @since 6.2.0
*
* @param int $start Byte offset into document where replacement span begins.
* @param int $length Byte length of span in document being replaced.
* @param string $text Span of text to insert in document to replace existing content from start to end.
*/
public function __construct( $start, $length, $text ) {
$this->start = $start;
$this->length = $length;
$this->text = $text;
}
}
class-wp-html-token.php 0000644 00000005360 15153115200 0011063 0 ustar 00 <?php
/**
* HTML API: WP_HTML_Token class
*
* @package WordPress
* @subpackage HTML-API
* @since 6.4.0
*/
/**
* Core class used by the HTML processor during HTML parsing
* for referring to tokens in the input HTML string.
*
* This class is designed for internal use by the HTML processor.
*
* @since 6.4.0
*
* @access private
*
* @see WP_HTML_Processor
*/
class WP_HTML_Token {
/**
* Name of bookmark corresponding to source of token in input HTML string.
*
* Having a bookmark name does not imply that the token still exists. It
* may be that the source token and underlying bookmark was wiped out by
* some modification to the source HTML.
*
* @since 6.4.0
*
* @var string
*/
public $bookmark_name = null;
/**
* Name of node; lowercase names such as "marker" are not HTML elements.
*
* For HTML elements/tags this value should come from WP_HTML_Processor::get_tag().
*
* @since 6.4.0
*
* @see WP_HTML_Processor::get_tag()
*
* @var string
*/
public $node_name = null;
/**
* Whether node contains the self-closing flag.
*
* A node may have a self-closing flag when it shouldn't. This value
* only reports if the flag is present in the original HTML.
*
* @since 6.4.0
*
* @see https://html.spec.whatwg.org/#self-closing-flag
*
* @var bool
*/
public $has_self_closing_flag = false;
/**
* Called when token is garbage-collected or otherwise destroyed.
*
* @var callable|null
*/
public $on_destroy = null;
/**
* Constructor - creates a reference to a token in some external HTML string.
*
* @since 6.4.0
*
* @param string $bookmark_name Name of bookmark corresponding to location in HTML where token is found.
* @param string $node_name Name of node token represents; if uppercase, an HTML element; if lowercase, a special value like "marker".
* @param bool $has_self_closing_flag Whether the source token contains the self-closing flag, regardless of whether it's valid.
* @param callable $on_destroy Function to call when destroying token, useful for releasing the bookmark.
*/
public function __construct( $bookmark_name, $node_name, $has_self_closing_flag, $on_destroy = null ) {
$this->bookmark_name = $bookmark_name;
$this->node_name = $node_name;
$this->has_self_closing_flag = $has_self_closing_flag;
$this->on_destroy = $on_destroy;
}
/**
* Destructor.
*
* @since 6.4.0
*/
public function __destruct() {
if ( is_callable( $this->on_destroy ) ) {
call_user_func( $this->on_destroy, $this->bookmark_name );
}
}
/**
* Wakeup magic method.
*
* @since 6.4.2
*/
public function __wakeup() {
throw new \LogicException( __CLASS__ . ' should never be unserialized' );
}
}
class-wp-html-unsupported-exception.php 0000644 00000001504 15153115200 0014323 0 ustar 00 <?php
/**
* HTML API: WP_HTML_Unsupported_Exception class
*
* @package WordPress
* @subpackage HTML-API
* @since 6.4.0
*/
/**
* Core class used by the HTML processor during HTML parsing
* for indicating that a given operation is unsupported.
*
* This class is designed for internal use by the HTML processor.
*
* The HTML API aims to operate in compliance with the HTML5
* specification, but does not implement the full specification.
* In cases where it lacks support it should not cause breakage
* or unexpected behavior. In the cases where it recognizes that
* it cannot proceed, this class is used to abort from any
* operation and signify that the given HTML cannot be processed.
*
* @since 6.4.0
*
* @access private
*
* @see WP_HTML_Processor
*/
class WP_HTML_Unsupported_Exception extends Exception {
}