EVOLUTION-MANAGER
Edit File: class-wp-html-active-formatting-elements.php
<?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( WP_HTML_Token $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; } /** * Inserts a "marker" at the end of the list of active formatting elements. * * > 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. * * @see https://html.spec.whatwg.org/#concept-parser-marker * * @since 6.7.0 */ public function insert_marker(): void { $this->push( new WP_HTML_Token( null, 'marker', false ) ); } /** * 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( WP_HTML_Token $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( WP_HTML_Token $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 ]; } } /** * Clears the list of active formatting elements up to the last marker. * * > When the steps below require the UA to clear the list of active formatting elements up to * > the last marker, the UA must perform the following steps: * > * > 1. Let entry be the last (most recently added) entry in the list of active * > formatting elements. * > 2. Remove entry from the list of active formatting elements. * > 3. If entry was a marker, then stop the algorithm at this point. * > The list has been cleared up to the last marker. * > 4. Go to step 1. * * @see https://html.spec.whatwg.org/multipage/parsing.html#clear-the-list-of-active-formatting-elements-up-to-the-last-marker * * @since 6.7.0 */ public function clear_up_to_last_marker(): void { foreach ( $this->walk_up() as $item ) { array_pop( $this->stack ); if ( 'marker' === $item->node_name ) { break; } } } }