Html api/add html processor

src/wp-includes/html-api/class-wp-html-element-stack-item.php

@@ -0,0 +1,45 @@
+<?php
+
+class WP_HTML_Element_Stack_Item {
+	const IS_CLOSER = 1 << 0;
+	const HAS_SELF_CLOSING_FLAG = 1 << 1;
+
+	/**
+	 * Stores the name of the bookmark pointing to the element at the position of the item.
+	 *
+	 * @var string|null
+	 */
+	public $bookmark_name = null;
+
+	/**
+	 * Stores the element class name for the element at the position of the item.
+	 *
+	 * This is the name of the PHP class representing the element.
+	 * For example, `WP_HTMLDivElement` from calling `WP_HTMLDivElement::class`.
+	 *
+	 * @var string|null
+	 */
+	public $element = null;
+
+	/**
+	 * Properties about this item in the stack that are relevant for relating opening and closing tags.
+	 *
+	 * @var int
+	 */
+	public $flags = 0;
+
+	/**
+	 * Pointer to related item on the stack, if one exists.
+	 * For example, a tag opener that opens the current tag closer.
+	 *
+	 * @var WP_HTML_Element_Stack_Item|null
+	 */
+	public $related_item = null;
+
+	public function __construct( $bookmark_name, $element, $flags, $related_item = null ) {
+		$this->bookmark_name = $bookmark_name;
+		$this->element       = $element;
+		$this->flags         = $flags;
+		$this->related_item  = $related_item;
+	}
+}

src/wp-includes/html-api/class-wp-html-element-stack.php

@@ -0,0 +1,266 @@
+<?php
+
+class WP_HTML_Element_Stack {
+	/**
+	 * Stack holding HTML tokens, tag openers, tag closers, or plain bookmarks.
+	 *
+	 * @var WP_HTML_Element_Stack_Item[]
+	 */
+	public $stack = array();
+
+	public function __construct( $bookmark_name, $element, $flags ) {
+		$this->bookmark_name = $bookmark_name;
+		$this->element       = $element;
+		$this->flags         = $flags;
+	}
+
+	/**
+	 * Add an item to the top of the stack.
+	 *
+	 * @TODO: Do we need to insertion-sort these?
+	 *
+	 * @param $stack_item
+	 * @return void
+	 */
+	public function push( $stack_item ) {
+		$this->stack[] = $stack_item;
+	}
+
+	public function count() {
+		return count( $this->stack );
+	}
+
+	/**
+	 * Returns the bottom-most node on the stack.
+	 *
+	 * @return WP_HTML_Element_Stack_Item|null
+	 */
+	public function current_node() {
+		$count = $this->count();
+
+		return $this->count() > 0
+			? $this->stack[ $count - 1 ]
+			: null;
+	}
+
+	/**
+	 * Returns whether the given element is on the stack.
+	 *
+	 * @param string $element the ::class name of the element to check for.
+	 * @return boolean whether the given element is on the stack.
+	 */
+	public function has_element( $element ) {
+		for ( $i = count( $this->stack ) - 1; $i > 0; $i++ ) {
+			if ( $this->stack[ $i ]->element === $element ) {
+				return true;
+			}
+		}
+
+		return false;
+	}
+
+	/**
+	 * Returns whether an element is in a specific scope.
+	 *
+	 * @see https://html.spec.whatwg.org/#has-an-element-in-the-specific-scope
+	 *
+	 * @param string   $element The target node.
+	 * @param string[] $termination_list List of elements that terminate the search.
+	 * @return bool
+	 */
+	public function has_element_in_specific_scope( $element, $termination_list ) {
+		$i = $this->count();
+		if ( $i === 0 ) {
+			return false;
+		}
+
+		$node = $this->stack[ --$i ];
+
+		if ( $node->element === $element ) {
+			return true;
+		}
+
+		if ( in_array( $element, $termination_list, true ) ) {
+			return false;
+		}
+
+		while ( $i > 0 && null !== ( $node = $this->stack[ --$i ] ) ) {
+			if ( $node->element === $element ) {
+				return true;
+			}
+		}
+
+		return false;
+	}
+
+	/**
+	 * Returns whether a given element is in a particular scope.
+	 *
+	 * @see https://html.spec.whatwg.org/#has-an-element-in-scope
+	 *
+	 * @param string $element
+	 * @return bool
+	 */
+	public function has_element_in_particular_scope( $element ) {
+		return $this->has_element_in_specific_scope( $element, array(
+			WP_HTMLAppletElement::class,
+			WP_HTMLCaptionElement::class,
+			WP_HTMLHtmlElement::class,
+			WP_HTMLTableElement::class,
+			WP_HTMLTdElement::class,
+			WP_HTMLThElement::class,
+			WP_HTMLMarqueeElement::class,
+			WP_HTMLObjectElement::class,
+			WP_HTMLTemplateElement::class,
+			WP_MathML_Mi_Element::class,
+			WP_MathML_Mo_Element::class,
+			WP_MathML_Mn_Element::class,
+			WP_MathML_Ms_Element::class,
+			WP_MathML_Mtext_Element::class,
+			WP_MathML_Annotation_Xml_Element::class,
+			WP_SVG_ForeignObject_Element::class,
+			WP_SVG_Description_Element::class,
+			WP_SVG_Title_Element::class,
+		) );
+	}
+
+	/**
+	 * Returns whether a given element is in list item scope.
+	 *
+	 * @see https://html.spec.whatwg.org/#has-an-element-in-list-item-scope
+	 *
+	 * @param $element
+	 * @return void
+	 */
+	public function has_element_in_list_item_scope( $element ) {
+		return $this->has_element_in_specific_scope( $element, array(
+			WP_HTMLAppletElement::class,
+			WP_HTMLCaptionElement::class,
+			WP_HTMLHtmlElement::class,
+			WP_HTMLTableElement::class,
+			WP_HTMLTdElement::class,
+			WP_HTMLThElement::class,
+			WP_HTMLMarqueeElement::class,
+			WP_HTMLObjectElement::class,
+			WP_HTMLTemplateElement::class,
+			WP_MathML_Mi_Element::class,
+			WP_MathML_Mo_Element::class,
+			WP_MathML_Mn_Element::class,
+			WP_MathML_Ms_Element::class,
+			WP_MathML_Mtext_Element::class,
+			WP_MathML_Annotation_Xml_Element::class,
+			WP_SVG_ForeignObject_Element::class,
+			WP_SVG_Description_Element::class,
+			WP_SVG_Title_Element::class,
+
+			// Additionally these elements.
+			WP_HTMLOlElement::class,
+			WP_HTMLUlElement::class,
+		) );
+	}
+
+	/**
+	 * Returns whether a given element is in button scope.
+	 *
+	 * @see https://html.spec.whatwg.org/#has-an-element-in-button-scope
+	 *
+	 * @param string $element
+	 * @return boolean
+	 */
+	public function has_element_in_button_scope( $element ) {
+		return $this->has_element_in_specific_scope( $element, array(
+			WP_HTMLAppletElement::class,
+			WP_HTMLCaptionElement::class,
+			WP_HTMLHtmlElement::class,
+			WP_HTMLTableElement::class,
+			WP_HTMLTdElement::class,
+			WP_HTMLThElement::class,
+			WP_HTMLMarqueeElement::class,
+			WP_HTMLObjectElement::class,
+			WP_HTMLTemplateElement::class,
+			WP_MathML_Mi_Element::class,
+			WP_MathML_Mo_Element::class,
+			WP_MathML_Mn_Element::class,
+			WP_MathML_Ms_Element::class,
+			WP_MathML_Mtext_Element::class,
+			WP_MathML_Annotation_Xml_Element::class,
+			WP_SVG_ForeignObject_Element::class,
+			WP_SVG_Description_Element::class,
+			WP_SVG_Title_Element::class,
+
+			// Additionally these elements.
+			WP_HTMLButtonElement::class,
+		) );
+	}
+
+	/**
+	 * Returns whether the given element is in table scope.
+	 *
+	 * @see https://html.spec.whatwg.org/#has-an-element-in-table-scope
+	 *
+	 * @param string $element
+	 * @return bool
+	 */
+	public function has_element_in_table_scope( $element ) {
+		return $this->has_element_in_specific_scope( $element, array(
+			WP_HTMLAppletElement::class,
+			WP_HTMLCaptionElement::class,
+			WP_HTMLHtmlElement::class,
+			WP_HTMLTableElement::class,
+			WP_HTMLTdElement::class,
+			WP_HTMLThElement::class,
+			WP_HTMLMarqueeElement::class,
+			WP_HTMLObjectElement::class,
+			WP_HTMLTemplateElement::class,
+			WP_MathML_Mi_Element::class,
+			WP_MathML_Mo_Element::class,
+			WP_MathML_Mn_Element::class,
+			WP_MathML_Ms_Element::class,
+			WP_MathML_Mtext_Element::class,
+			WP_MathML_Annotation_Xml_Element::class,
+			WP_SVG_ForeignObject_Element::class,
+			WP_SVG_Description_Element::class,
+			WP_SVG_Title_Element::class,
+
+			// Additionally these elements.
+			WP_HTMLHtmlElement::class,
+			WP_HTMLTableElement::class,
+			WP_HTMLTemplateElement::class,
+		) );
+	}
+
+	/**
+	 * Returns whether a given element is in select scope.
+	 *
+	 * @see https://html.spec.whatwg.org/#has-an-element-in-select-scope
+	 *
+	 * @param string $element
+	 * @return bool
+	 */
+	public function has_element_in_select_scope( $element ) {
+		return $this->has_element_in_specific_scope( $element, array(
+			WP_HTMLAppletElement::class,
+			WP_HTMLCaptionElement::class,
+			WP_HTMLHtmlElement::class,
+			WP_HTMLTableElement::class,
+			WP_HTMLTdElement::class,
+			WP_HTMLThElement::class,
+			WP_HTMLMarqueeElement::class,
+			WP_HTMLObjectElement::class,
+			WP_HTMLTemplateElement::class,
+			WP_MathML_Mi_Element::class,
+			WP_MathML_Mo_Element::class,
+			WP_MathML_Mn_Element::class,
+			WP_MathML_Ms_Element::class,
+			WP_MathML_Mtext_Element::class,
+			WP_MathML_Annotation_Xml_Element::class,
+			WP_SVG_ForeignObject_Element::class,
+			WP_SVG_Description_Element::class,
+			WP_SVG_Title_Element::class,
+
+			// Additionally these elements.
+			WP_HTMLOptgroupElement::class,
+			WP_HTMLOptionElement::class,
+		) );
+	}
+}

src/wp-includes/html-api/class-wp-html-processor.php

@@ -24,12 +24,20 @@ class WP_HTML_Processor extends WP_HTML_Tag_Processor {
 	 * @return boolean Whether an element was found.
 	 */
 	public function step( $insertion_mode = null ) {
-		switch ( $insertion_mode ?: $this->insertion_mode ) {
-			case 'in-body':
-				return $this->step_in_body();
+		try {
+			switch ( $insertion_mode ?: $this->insertion_mode ) {
+				case 'in-body':
+					return $this->step_in_body();
 
-			default:
-				return self::NOT_IMPLEMENTED_YET;
+				default:
+					return self::NOT_IMPLEMENTED_YET;
+			}
+		} catch ( Exception $e ) {
+			/*
+			 * Exceptions are used in this class to escape deep call stacks that
+			 * otherwise might involve messier calling and return conventions.
+			 */
+			return false;
 		}
 	}
 
@@ -215,7 +223,7 @@ private function close_p_element() {
 	 * @return void
 	 */
 	private function generate_implied_end_tags( $except_for_this_element = null ) {
-		
+
 	}
 
 	/**