HTML API: Complete missing tags in the IN BODY insertion mode.

src/wp-includes/html-api/class-wp-html-active-formatting-elements.php

@@ -86,6 +86,22 @@ public function current_node() {
  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.
  *
@@ -184,4 +200,30 @@ public function walk_up() {
  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;
+ }
+ }
+	}
 }

src/wp-includes/html-api/class-wp-html-open-elements.php

@@ -101,6 +101,49 @@ public function set_push_handler( Closure $handler ): void {
  $this->push_handler = $handler;
 	}
 
+	/**
+ * Returns the name of the node at the nth position on the stack
+ * of open elements, or `null` if no such position exists.
+ *
+ * Note that this uses a 1-based index, which represents the
+ * "nth item" on the stack, counting from the top, where the
+ * top-most element is the 1st, the second is the 2nd, etc...
+ *
+ * @since 6.7.0
+ *
+ * @param int $nth Retrieve the nth item on the stack, with 1 being
+ * the top element, 2 being the second, etc...
+ * @return string|null Name of the node on the stack at the given location,
+ * or `null` if the location isn't on the stack.
+ */
+	public function at( int $nth ): ?string {
+ foreach ( $this->walk_down() as $item ) {
+ if ( 0 === --$nth ) {
+ return $item->node_name;
+ }
+ }
+
+ return null;
+	}
+
+	/**
+ * Reports if a node of a given name is in the stack of open elements.
+ *
+ * @since 6.7.0
+ *
+ * @param string $node_name Name of node for which to check.
+ * @return bool Whether a node of the given name is in the stack of open elements.
+ */
+	public function contains( string $node_name ): bool {
+ foreach ( $this->walk_up() as $item ) {
+ if ( $node_name === $item->node_name ) {
+ return true;
+ }
+ }
+
+ return false;
+	}
+
 	/**
  * Reports if a specific node is in the stack of open elements.
  *
@@ -111,7 +154,7 @@ public function set_push_handler( Closure $handler ): void {
  */
 	public function contains_node( WP_HTML_Token $token ): bool {
  foreach ( $this->walk_up() as $item ) {
- if ( $token->bookmark_name === $item->bookmark_name ) {
+ if ( $token === $item ) {
  return true;
  }
  }
@@ -210,11 +253,6 @@ public function has_element_in_specific_scope( string $tag_name, $termination_li
  return true;
  }
 
- switch ( $node->node_name ) {
- case 'HTML':
- return false;
- }
-
  if ( in_array( $node->node_name, $termination_list, true ) ) {
  return false;
  }
@@ -226,7 +264,31 @@ public function has_element_in_specific_scope( string $tag_name, $termination_li
 	/**
  * Returns whether a particular element is in scope.
  *
+ * > The stack of open elements is said to have a particular element in
+ * > scope when it has that element in the specific scope consisting of
+ * > the following element types:
+ * >
+ * > - applet
+ * > - caption
+ * > - html
+ * > - table
+ * > - td
+ * > - th
+ * > - marquee
+ * > - object
+ * > - template
+ * > - MathML mi
+ * > - MathML mo
+ * > - MathML mn
+ * > - MathML ms
+ * > - MathML mtext
+ * > - MathML annotation-xml
+ * > - SVG foreignObject
+ * > - SVG desc
+ * > - SVG title
+ *
  * @since 6.4.0
+ * @since 6.7.0 Supports all required HTML elements.
  *
  * @see https://html.spec.whatwg.org/#has-an-element-in-scope
  *
@@ -237,23 +299,34 @@ public function has_element_in_scope( string $tag_name ): bool {
  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.
- */
+ 'APPLET',
+ 'CAPTION',
+ 'HTML',
+ 'TABLE',
+ 'TD',
+ 'TH',
+ 'MARQUEE',
+ 'OBJECT',
+ 'TEMPLATE',
+ // @todo: Support SVG and MathML nodes when support for foreign content is added.
  )
  );
 	}
 
 	/**
  * Returns whether a particular element is in list item scope.
  *
+ * > The stack of open elements is said to have a particular element
+ * > in list item scope when it has that element in the specific scope
+ * > consisting of the following element types:
+ * >
+ * > - All the element types listed above for the has an element in scope algorithm.
+ * > - ol in the HTML namespace
+ * > - ul in the HTML namespace
+ *
  * @since 6.4.0
  * @since 6.5.0 Implemented: no longer throws on every invocation.
+ * @since 6.7.0 Supports all required HTML elements.
  *
  * @see https://html.spec.whatwg.org/#has-an-element-in-list-item-scope
  *
@@ -264,43 +337,88 @@ public function has_element_in_list_item_scope( string $tag_name ): bool {
  return $this->has_element_in_specific_scope(
  $tag_name,
  array(
- // There are more elements that belong here which aren't currently supported.
+ 'APPLET',
+ 'BUTTON',
+ 'CAPTION',
+ 'HTML',
+ 'TABLE',
+ 'TD',
+ 'TH',
+ 'MARQUEE',
+ 'OBJECT',
  'OL',
+ 'TEMPLATE',
  'UL',
+ // @todo: Support SVG and MathML nodes when support for foreign content is added.
  )
  );
 	}
 
 	/**
  * Returns whether a particular element is in button scope.
  *
+ * > The stack of open elements is said to have a particular element
+ * > in button scope when it has that element in the specific scope
+ * > consisting of the following element types:
+ * >
+ * > - All the element types listed above for the has an element in scope algorithm.
+ * > - button in the HTML namespace
+ *
  * @since 6.4.0
+ * @since 6.7.0 Supports all required HTML elements.
  *
  * @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( string $tag_name ): bool {
- return $this->has_element_in_specific_scope( $tag_name, array( 'BUTTON' ) );
+ return $this->has_element_in_specific_scope(
+ $tag_name,
+ array(
+ 'APPLET',
+ 'BUTTON',
+ 'CAPTION',
+ 'HTML',
+ 'TABLE',
+ 'TD',
+ 'TH',
+ 'MARQUEE',
+ 'OBJECT',
+ 'TEMPLATE',
+ // @todo: Support SVG and MathML nodes when support for foreign content is added.
+ )
+ );
 	}
 
 	/**
  * Returns whether a particular element is in table scope.
  *
+ * > The stack of open elements is said to have a particular element
+ * > in table scope when it has that element in the specific scope
+ * > consisting of the following element types:
+ * >
+ * > - html in the HTML namespace
+ * > - table in the HTML namespace
+ * > - template in the HTML namespace
+ *
  * @since 6.4.0
+ * @since 6.7.0 Full implementation.
  *
  * @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( string $tag_name ): bool {
- 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.
+ return $this->has_element_in_specific_scope(
+ $tag_name,
+ array(
+ 'HTML',
+ 'TABLE',
+ 'TEMPLATE',
+ )
+ );
 	}
 
 	/**
@@ -540,7 +658,16 @@ public function after_element_push( WP_HTML_Token $item ): void {
  * cases where the precalculated value needs to change.
  */
  switch ( $item->node_name ) {
+ case 'APPLET':
  case 'BUTTON':
+ case 'CAPTION':
+ case 'HTML':
+ case 'TABLE':
+ case 'TD':
+ case 'TH':
+ case 'MARQUEE':
+ case 'OBJECT':
+ case 'TEMPLATE':
  $this->has_p_in_button_scope = false;
  break;
 
@@ -573,11 +700,17 @@ public function after_element_pop( WP_HTML_Token $item ): void {
  * cases where the precalculated value needs to change.
  */
  switch ( $item->node_name ) {
+ case 'APPLET':
  case 'BUTTON':
- $this->has_p_in_button_scope = $this->has_element_in_button_scope( 'P' );
- break;
-
+ case 'CAPTION':
+ case 'HTML':
  case 'P':
+ case 'TABLE':
+ case 'TD':
+ case 'TH':
+ case 'MARQUEE':
+ case 'OBJECT':
+ case 'TEMPLATE':
  $this->has_p_in_button_scope = $this->has_element_in_button_scope( 'P' );
  break;
  }