Interactivity API: Use modules instead of scripts in the frontend

docs/reference-guides/core-blocks.md

@@ -378,7 +378,7 @@ Insert an image to make a visual statement. ([Source](https://github.com/WordPre
 
 -	**Name:** core/image
 -	**Category:** media
--	**Supports:** align (center, full, left, right, wide), anchor, color (~~background~~, ~~text~~), filter (duotone)
+-	**Supports:** align (center, full, left, right, wide), anchor, color (~~background~~, ~~text~~), filter (duotone), interactivity
 -	**Attributes:** alt, aspectRatio, caption, height, href, id, lightbox, linkClass, linkDestination, linkTarget, rel, scale, sizeSlug, title, url, width
 
 ## Latest Comments

lib/compat/wordpress-6.5/class-wp-navigation-block-renderer.php

@@ -547,20 +547,28 @@ private static function get_nav_element_directives( $should_load_view_script ) {
 	 */
 	private static function handle_view_script_loading( $attributes, $block, $inner_blocks ) {
 		$should_load_view_script = static::should_load_view_script( $attributes, $inner_blocks );
+		$is_gutenberg_plugin     = defined( 'IS_GUTENBERG_PLUGIN' ) && IS_GUTENBERG_PLUGIN;
+		$view_js_file            = 'wp-block-navigation-view';
+		$script_handles          = $block->block_type->view_script_handles;
 
-		$view_js_file = 'wp-block-navigation-view';
-
-		// If the script already exists, there is no point in removing it from viewScript.
-		if ( ! wp_script_is( $view_js_file ) ) {
-			$script_handles = $block->block_type->view_script_handles;
-
-			// If the script is not needed, and it is still in the `view_script_handles`, remove it.
-			if ( ! $should_load_view_script && in_array( $view_js_file, $script_handles, true ) ) {
-				$block->block_type->view_script_handles = array_diff( $script_handles, array( $view_js_file ) );
+		if ( $is_gutenberg_plugin ) {
+			if ( $should_load_view_script ) {
+				gutenberg_enqueue_module( '@wordpress/block-library/navigation-block' );
 			}
-			// If the script is needed, but it was previously removed, add it again.
-			if ( $should_load_view_script && ! in_array( $view_js_file, $script_handles, true ) ) {
-				$block->block_type->view_script_handles = array_merge( $script_handles, array( $view_js_file ) );
+			// Remove the view script because we are using the module.
+			$block->block_type->view_script_handles = array_diff( $script_handles, array( $view_js_file ) );
+		} else {
+			// If the script already exists, there is no point in removing it from viewScript.
+			if ( ! wp_script_is( $view_js_file ) ) {
+
+				// If the script is not needed, and it is still in the `view_script_handles`, remove it.
+				if ( ! $should_load_view_script && in_array( $view_js_file, $script_handles, true ) ) {
+					$block->block_type->view_script_handles = array_diff( $script_handles, array( $view_js_file ) );
+				}
+				// If the script is needed, but it was previously removed, add it again.
+				if ( $should_load_view_script && ! in_array( $view_js_file, $script_handles, true ) ) {
+					$block->block_type->view_script_handles = array_merge( $script_handles, array( $view_js_file ) );
+				}
 			}
 		}
 	}

lib/experimental/interactivity-api/modules.php

@@ -0,0 +1,33 @@
+<?php
+/**
+ * Interactive modules.
+ *
+ * @package Gutenberg
+ * @subpackage Interactivity API
+ */
+
+/**
+ * Register the `@wordpress/interactivity` module.
+ */
+function gutenberg_register_interactivity_module() {
+	gutenberg_register_module(
+		'@wordpress/interactivity',
+		gutenberg_url( '/build/interactivity/index.min.js' ),
+		array(),
+		defined( 'GUTENBERG_VERSION' ) ? GUTENBERG_VERSION : get_bloginfo( 'version' )
+	);
+
+	// TODO: Replace with a simpler version that only provides support for import maps.
+	// TODO: Load only if the browser doesn't support import maps (https://github.com/guybedford/es-module-shims/issues/371).
+	wp_enqueue_script(
+		'es-module-shims',
+		gutenberg_url( '/build/importmap-polyfill.min.js' ),
+		array(),
+		null,
+		array(
+			'strategy' => 'defer',
+		)
+	);
+}
+
+add_action( 'wp_enqueue_scripts', 'gutenberg_register_interactivity_module' );

lib/experimental/modules/class-gutenberg-modules.php

@@ -0,0 +1,195 @@
+<?php
+/**
+ * Modules API: Gutenberg_Modules class.
+ *
+ * Native support for ES Modules and Import Maps.
+ *
+ * @package Gutenberg
+ * @subpackage Modules
+ */
+
+/**
+ * Gutenberg_Modules class
+ */
+class Gutenberg_Modules {
+	/**
+	 * An array of registered modules, keyed by module identifier.
+	 *
+	 * @var array
+	 */
+	private static $registered = array();
+
+	/**
+	 * An array of queued modules.
+	 *
+	 * @var string[]
+	 */
+	private static $enqueued = array();
+
+	/**
+	 * Registers the module if no module with that module identifier already
+	 * exists.
+	 *
+	 * @param string           $module_identifier The identifier of the module. Should be unique. It will be used in the final import map.
+	 * @param string           $src               Full URL of the module, or path of the script relative to the WordPress root directory.
+	 * @param array            $dependencies      Optional. An array of module identifiers of the static and dynamic dependencies of this module. It can be an indexed array, in which case all the dependencies are static, or it can be an associative array, in which case it has to contain the keys `static` and `dynamic`.
+	 * @param string|bool|null $version           Optional. String specifying module version number. It is added to the URL as a query string for cache busting purposes. If SCRIPT_DEBUG is true, a timestamp is used. If it is set to false, a version number is automatically added equal to current installed WordPress version. If set to null, no version is added.
+	 */
+	public static function register( $module_identifier, $src, $dependencies = array(), $version = false ) {
+		// Register the module if it's not already registered.
+		if ( ! isset( self::$registered[ $module_identifier ] ) ) {
+			$deps = array(
+				'static'  => isset( $dependencies['static'] ) || isset( $dependencies['dynamic'] ) ? $dependencies['static'] ?? array() : $dependencies,
+				'dynamic' => isset( $dependencies['dynamic'] ) ? $dependencies['dynamic'] : array(),
+			);
+
+			self::$registered[ $module_identifier ] = array(
+				'src'          => $src,
+				'version'      => $version,
+				'dependencies' => $deps,
+			);
+		}
+	}
+
+	/**
+	 * Enqueues a module in the page.
+	 *
+	 * @param string $module_identifier The identifier of the module.
+	 */
+	public static function enqueue( $module_identifier ) {
+		// Add the module to the queue if it's not already there.
+		if ( ! in_array( $module_identifier, self::$enqueued, true ) ) {
+			self::$enqueued[] = $module_identifier;
+		}
+	}
+
+	/**
+	 * Returns the import map array.
+	 *
+	 * @return array Associative array with 'imports' key mapping to an array of module identifiers and their respective source strings.
+	 */
+	public static function get_import_map() {
+		$imports = array();
+		foreach ( self::get_dependencies( self::$enqueued, array( 'static', 'dynamic' ) ) as $module_identifier => $module ) {
+			$imports[ $module_identifier ] = $module['src'] . self::get_version_query_string( $module['version'] );
+		}
+		return array( 'imports' => $imports );
+	}
+
+	/**
+	 * Prints the import map.
+	 */
+	public static function print_import_map() {
+		$import_map = self::get_import_map();
+		if ( ! empty( $import_map['imports'] ) ) {
+			echo '<script type="importmap">' . wp_json_encode( self::get_import_map(), JSON_HEX_TAG | JSON_HEX_AMP ) . '</script>';
+		}
+	}
+
+	/**
+	 * Prints all the enqueued modules using <script type="module">.
+	 */
+	public static function print_enqueued_modules() {
+		foreach ( self::$enqueued as $module_identifier ) {
+			if ( isset( self::$registered[ $module_identifier ] ) ) {
+				$module = self::$registered[ $module_identifier ];
+				wp_print_script_tag(
+					array(
+						'type' => 'module',
+						'src'  => $module['src'] . self::get_version_query_string( $module['version'] ),
+						'id'   => $module_identifier,
+					)
+				);
+			}
+		}
+	}
+
+	/**
+	 * Prints the link tag with rel="modulepreload" for all the static
+	 * dependencies of the enqueued modules.
+	 */
+	public static function print_module_preloads() {
+		foreach ( self::get_dependencies( self::$enqueued, array( 'static' ) ) as $dependency_identifier => $module ) {
+				echo '<link rel="modulepreload" href="' . $module['src'] . self::get_version_query_string( $module['version'] ) . '" id="' . $dependency_identifier . '">';
+		}
+	}
+
+	/**
+	 * Gets the module's version. It either returns a timestamp (if SCRIPT_DEBUG
+	 * is true), the explicit version of the module if it is set and not false, or
+	 * an empty string if none of the above conditions are met.
+	 *
+	 * @param array $version The version of the module.
+	 * @return string A string presenting the version.
+	 */
+	private static function get_version_query_string( $version ) {
+		if ( SCRIPT_DEBUG ) {
+			return '?ver=' . time();
+		} elseif ( false === $version ) {
+			return '?ver=' . get_bloginfo( 'version' );
+		} elseif ( null !== $version ) {
+			return '?ver=' . $version;
+		}
+		return '';
+	}
+
+	/**
+	 * Returns all unique static and/or dynamic dependencies for the received modules. It's
+	 * recursive, so it will also get the static or dynamic dependencies of the dependencies.
+	 *
+	 * @param array $module_identifiers The identifiers of the modules to get dependencies for.
+	 * @param array $types              The type of dependencies to retrieve. It can be `static`, `dynamic` or both.
+	 * @return array The array containing the unique dependencies of the modules.
+	 */
+	private static function get_dependencies( $module_identifiers, $types = array( 'static', 'dynamic' ) ) {
+		return array_reduce(
+			$module_identifiers,
+			function ( $dependency_modules, $module_identifier ) use ( $types ) {
+				if ( ! isset( self::$registered[ $module_identifier ] ) ) {
+					return $dependency_modules;
+				}
+
+				$dependencies = array();
+				foreach ( $types as $type ) {
+					$dependencies = array_merge( $dependencies, self::$registered[ $module_identifier ]['dependencies'][ $type ] );
+				}
+				$dependencies       = array_unique( $dependencies );
+				$dependency_modules = array_intersect_key( self::$registered, array_flip( $dependencies ) );
+
+				return array_merge( $dependency_modules, $dependency_modules, self::get_dependencies( $dependencies, $types ) );
+			},
+			array()
+		);
+	}
+}
+
+/**
+ * Registers a JavaScript module. It will be added to the import map.
+ *
+ * @param string           $module_identifier The identifier of the module. Should be unique. It will be used in the final import map.
+ * @param string           $src               Full URL of the module, or path of the script relative to the WordPress root directory.
+ * @param array            $dependencies      Optional. An array of module identifiers of the static and dynamic dependencies of this module. It can be an indexed array, in which case all the dependencies are static, or it can be an associative array, in which case it has to contain the keys `static` and `dynamic`.
+ * @param string|bool|null $version           Optional. String specifying module version number. It is added to the URL as a query string for cache busting purposes. If SCRIPT_DEBUG is true, a timestamp is used. If it is set to false, a version number is automatically added equal to current installed WordPress version. If set to null, no version is added.
+ */
+function gutenberg_register_module( $module_identifier, $src, $dependencies = array(), $version = false ) {
+	Gutenberg_Modules::register( $module_identifier, $src, $dependencies, $version );
+}
+
+/**
+ * Enqueues a JavaScript module. It will be added to both the import map and a
+ * script tag with the "module" type.
+ *
+ * @param string $module_identifier The identifier of the module. Should be unique. It will be used in the final import map.
+ */
+function gutenberg_enqueue_module( $module_identifier ) {
+	Gutenberg_Modules::enqueue( $module_identifier );
+}
+
+// Prints the import map in the head tag.
+add_action( 'wp_head', array( 'Gutenberg_Modules', 'print_import_map' ) );
+
+// Prints the enqueued modules in the head tag.
+add_action( 'wp_head', array( 'Gutenberg_Modules', 'print_enqueued_modules' ) );
+
+// Prints the preloaded modules in the head tag.
+add_action( 'wp_head', array( 'Gutenberg_Modules', 'print_module_preloads' ) );

lib/load.php

@@ -115,7 +115,7 @@ function gutenberg_is_experiment_enabled( $name ) {
 
 require __DIR__ . '/experimental/interactivity-api/class-wp-interactivity-store.php';
 require __DIR__ . '/experimental/interactivity-api/store.php';
-require __DIR__ . '/experimental/interactivity-api/scripts.php';
+require __DIR__ . '/experimental/interactivity-api/modules.php';
 require __DIR__ . '/experimental/interactivity-api/class-wp-directive-processor.php';
 require __DIR__ . '/experimental/interactivity-api/class-wp-directive-context.php';
 require __DIR__ . '/experimental/interactivity-api/directive-processing.php';
@@ -125,6 +125,8 @@ function gutenberg_is_experiment_enabled( $name ) {
 require __DIR__ . '/experimental/interactivity-api/directives/wp-style.php';
 require __DIR__ . '/experimental/interactivity-api/directives/wp-text.php';
 
+require __DIR__ . '/experimental/modules/class-gutenberg-modules.php';
+
 // Fonts API / Font Face.
 remove_action( 'plugins_loaded', '_wp_theme_json_webfonts_handler' ); // Turns off WordPress 6.0's stopgap handler.
 

package.json

@@ -91,6 +91,7 @@
 		"@wordpress/warning": "file:packages/warning",
 		"@wordpress/widgets": "file:packages/widgets",
 		"@wordpress/wordcount": "file:packages/wordcount",
+		"es-module-shims": "^1.8.2",
 		"wicg-inert": "3.1.2"
 	},
 	"devDependencies": {