Interactivity API: Server Directive Processing

composer.json

@@ -10,6 +10,7 @@
 		"issues": "https://core.trac.wordpress.org/"
 	},
 	"require": {
+		"ext-json": "*",
 		"php": ">=7.0"
 	},
 	"suggest": {

src/wp-includes/interactivity-api/class-wp-interactivity-api-directives-processor.php

@@ -0,0 +1,244 @@
+<?php
+/**
+ * Interactivity API: WP_Interactivity_API_Directives_Processor class.
+ *
+ * @package WordPress
+ * @subpackage Interactivity API
+ * @since 6.5.0
+ */
+
+/**
+ * Class used to iterate over the tags of an HTML string and help process the
+ * directive attributes.
+ *
+ * @since 6.5.0
+ *
+ * @access private
+ */
+final class WP_Interactivity_API_Directives_Processor extends WP_HTML_Tag_Processor {
+	/**
+	 * List of tags whose closer tag is not visited by the WP_HTML_Tag_Processor.
+	 *
+	 * @since 6.5.0
+	 * @var string[]
+	 */
+	const TAGS_THAT_DONT_VISIT_CLOSER_TAG = array(
+		'SCRIPT',
+		'IFRAME',
+		'NOEMBED',
+		'NOFRAMES',
+		'STYLE',
+		'TEXTAREA',
+		'TITLE',
+		'XMP',
+	);
+
+	/**
+	 * Returns the content between two balanced template tags.
+	 *
+	 * It positions the cursor in the closer tag of the balanced template tag,
+	 * if it exists.
+	 *
+	 * @since 6.5.0
+	 *
+	 * @access private
+	 *
+	 * @return string|null The content between the current opener template tag and its matching closer tag or null if it
+	 *                     doesn't find the matching closing tag or the current tag is not a template opener tag.
+	 */
+	public function get_content_between_balanced_template_tags() {
+		if ( 'TEMPLATE' !== $this->get_tag() ) {
+			return null;
+		}
+
+		$positions = $this->get_after_opener_tag_and_before_closer_tag_positions();
+		if ( ! $positions ) {
+			return null;
+		}
+		list( $after_opener_tag, $before_closer_tag ) = $positions;
+
+		return substr( $this->html, $after_opener_tag, $before_closer_tag - $after_opener_tag );
+	}
+
+	/**
+	 * Sets the content between two balanced tags.
+	 *
+	 * @since 6.5.0
+	 *
+	 * @access private
+	 *
+	 * @param string $new_content The string to replace the content between the matching tags.
+	 * @return bool Whether the content was successfully replaced.
+	 */
+	public function set_content_between_balanced_tags( string $new_content ): bool {
+		$positions = $this->get_after_opener_tag_and_before_closer_tag_positions( true );
+		if ( ! $positions ) {
+			return false;
+		}
+		list( $after_opener_tag, $before_closer_tag ) = $positions;
+
+		$this->lexical_updates[] = new WP_HTML_Text_Replacement(
+			$after_opener_tag,
+			$before_closer_tag - $after_opener_tag,
+			esc_html( $new_content )
+		);
+
+		return true;
+	}
+
+	/**
+	 * Appends content after the closing tag of a template tag.
+	 *
+	 * It positions the cursor in the closer tag of the balanced template tag,
+	 * if it exists.
+	 *
+	 * @access private
+	 *
+	 * @param string $new_content The string to append after the closing template tag.
+	 * @return bool Whether the content was successfully appended.
+	 */
+	public function append_content_after_template_tag_closer( string $new_content ): bool {
+		if ( empty( $new_content ) || 'TEMPLATE' !== $this->get_tag() || ! $this->is_tag_closer() ) {
+			return false;
+		}
+
+		// Flushes any changes.
+		$this->get_updated_html();
+
+		$bookmark = 'append_content_after_template_tag_closer';
+		$this->set_bookmark( $bookmark );
+		$after_closing_tag = $this->bookmarks[ $bookmark ]->start + $this->bookmarks[ $bookmark ]->length + 1;
+		$this->release_bookmark( $bookmark );
+
+		// Appends the new content.
+		$this->lexical_updates[] = new WP_HTML_Text_Replacement( $after_closing_tag, 0, $new_content );
+
+		return true;
+	}
+
+	/**
+	 * Gets the positions right after the opener tag and right before the closer
+	 * tag in a balanced tag.
+	 *
+	 * By default, it positions the cursor in the closer tag of the balanced tag.
+	 * If $rewind is true, it seeks back to the opener tag.
+	 *
+	 * @since 6.5.0
+	 *
+	 * @access private
+	 *
+	 * @param bool $rewind Optional. Whether to seek back to the opener tag after finding the positions. Defaults to false.
+	 * @return array|null Start and end byte position, or null when no balanced tag bookmarks.
+	 */
+	private function get_after_opener_tag_and_before_closer_tag_positions( bool $rewind = false ) {
+		// Flushes any changes.
+		$this->get_updated_html();
+
+		$bookmarks = $this->get_balanced_tag_bookmarks();
+		if ( ! $bookmarks ) {
+			return null;
+		}
+		list( $opener_tag, $closer_tag ) = $bookmarks;
+
+		$after_opener_tag  = $this->bookmarks[ $opener_tag ]->start + $this->bookmarks[ $opener_tag ]->length + 1;
+		$before_closer_tag = $this->bookmarks[ $closer_tag ]->start;
+
+		if ( $rewind ) {
+			$this->seek( $opener_tag );
+		}
+
+		$this->release_bookmark( $opener_tag );
+		$this->release_bookmark( $closer_tag );
+
+		return array( $after_opener_tag, $before_closer_tag );
+	}
+
+	/**
+	 * Returns a pair of bookmarks for the current opener tag and the matching
+	 * closer tag.
+	 *
+	 * It positions the cursor in the closer tag of the balanced tag, if it
+	 * exists.
+	 *
+	 * @since 6.5.0
+	 *
+	 * @return array|null A pair of bookmarks, or null if there's no matching closing tag.
+	 */
+	private function get_balanced_tag_bookmarks() {
+		static $i   = 0;
+		$opener_tag = 'opener_tag_of_balanced_tag_' . ++$i;
+
+		$this->set_bookmark( $opener_tag );
+		if ( ! $this->next_balanced_tag_closer_tag() ) {
+			$this->release_bookmark( $opener_tag );
+			return null;
+		}
+
+		$closer_tag = 'closer_tag_of_balanced_tag_' . ++$i;
+		$this->set_bookmark( $closer_tag );
+
+		return array( $opener_tag, $closer_tag );
+	}
+
+	/**
+	 * Finds the matching closing tag for an opening tag.
+	 *
+	 * When called while the processor is on an open tag, it traverses the HTML
+	 * until it finds the matching closer tag, respecting any in-between content,
+	 * including nested tags of the same name. Returns false when called on a
+	 * closer tag, a tag that doesn't have a closer tag (void), a tag that
+	 * doesn't visit the closer tag, or if no matching closing tag was found.
+	 *
+	 * @since 6.5.0
+	 *
+	 * @access private
+	 *
+	 * @return bool Whether a matching closing tag was found.
+	 */
+	public function next_balanced_tag_closer_tag(): bool {
+		$depth    = 0;
+		$tag_name = $this->get_tag();
+
+		if ( ! $this->has_and_visits_its_closer_tag() ) {
+			return false;
+		}
+
+		while ( $this->next_tag(
+			array(
+				'tag_name'    => $tag_name,
+				'tag_closers' => 'visit',
+			)
+		) ) {
+			if ( ! $this->is_tag_closer() ) {
+				++$depth;
+				continue;
+			}
+
+			if ( 0 === $depth ) {
+				return true;
+			}
+
+			--$depth;
+		}
+
+		return false;
+	}
+
+	/**
+	 * Checks whether the current tag has and will visit its matching closer tag.
+	 *
+	 * @since 6.5.0
+	 *
+	 * @access private
+	 *
+	 * @return bool Whether the current tag has a closer tag.
+	 */
+	public function has_and_visits_its_closer_tag(): bool {
+		$tag_name = $this->get_tag();
+
+		return null !== $tag_name && (
+			! WP_HTML_Processor::is_void( $tag_name ) &&
+			! in_array( $tag_name, self::TAGS_THAT_DONT_VISIT_CLOSER_TAG, true )
+		);
+	}
+}