Use slug instead of id for ref in Navigation block

docs/reference-guides/core-blocks.md

@@ -393,7 +393,7 @@ A collection of blocks that allow visitors to get around your site. ([Source](ht
 -	**Name:** core/navigation
 -	**Category:** theme
 -	**Supports:** align (full, wide), inserter, spacing (blockGap, units), typography (fontSize, lineHeight), ~~html~~
--	**Attributes:** __unstableLocation, backgroundColor, customBackgroundColor, customOverlayBackgroundColor, customOverlayTextColor, customTextColor, hasIcon, icon, maxNestingLevel, openSubmenusOnClick, overlayBackgroundColor, overlayMenu, overlayTextColor, ref, rgbBackgroundColor, rgbTextColor, showSubmenuIcon, templateLock, textColor
+-	**Attributes:** __unstableLocation, backgroundColor, customBackgroundColor, customOverlayBackgroundColor, customOverlayTextColor, customTextColor, hasIcon, icon, maxNestingLevel, openSubmenusOnClick, overlayBackgroundColor, overlayMenu, overlayTextColor, ref, rgbBackgroundColor, rgbTextColor, showSubmenuIcon, slug, templateLock, textColor
 
 ## Custom Link
 

lib/compat/wordpress-6.1/class-gutenberg-rest-navigation-controller.php

@@ -0,0 +1,117 @@
+<?php
+/**
+ * REST API: Gutenberg_REST_Templates_Controller class
+ *
+ * @package    Gutenberg
+ * @subpackage REST_API
+ */
+
+/**
+ * Base Templates REST API Controller.
+ */
+class Gutenberg_REST_Navigation_Controller extends WP_REST_Posts_Controller {
+
+	/**
+	 * Registers the controllers routes.
+	 *
+	 * @return void
+	 */
+	public function register_routes() {
+
+		parent::register_routes();
+
+		// Lists a single nav item based on the given id or slug.
+		register_rest_route(
+			$this->namespace,
+			'/' . $this->rest_base . '/((?P<id>[\d]+)|(?P<slug>[\w\-]+))',
+			array(
+				'args'        => array(
+					'slug' => array(
+						'description' => __( 'The slug identifier for a Navigation', 'gutenberg' ),
+						'type'        => 'string',
+					),
+				),
+				array(
+					'methods'             => WP_REST_Server::READABLE,
+					'callback'            => array( $this, 'get_item' ),
+					'permission_callback' => array( $this, 'get_item_permissions_check' ),
+					'args'                => $this->get_endpoint_args_for_item_schema( WP_REST_Server::READABLE ),
+				),
+				array(
+					'methods'             => WP_REST_Server::EDITABLE,
+					'callback'            => array( $this, 'update_item' ),
+					'permission_callback' => array( $this, 'update_item_permissions_check' ),
+					'args'                => $this->get_endpoint_args_for_item_schema( WP_REST_Server::EDITABLE ),
+				),
+				array(
+					'methods'             => WP_REST_Server::DELETABLE,
+					'callback'            => array( $this, 'delete_item' ),
+					'permission_callback' => array( $this, 'delete_item_permissions_check' ),
+					'args'                => array(
+						'force' => array(
+							'type'        => 'boolean',
+							'default'     => false,
+							'description' => __( 'Whether to bypass Trash and force deletion.' ),
+						),
+					),
+				),
+				'allow_batch' => $this->allow_batch,
+				'schema'      => array( $this, 'get_public_item_schema' ),
+			)
+		);
+	}
+
+	/**
+	 * Overide WP_REST_Posts_Controller parent function to query for
+	 * `wp_navigation` posts by slug (post_name) instead of ID.
+	 *
+	 * This is required to successfully process OPTIONS requests as with
+	 * these the `rest_request_before_callbacks` method which is used to
+	 * map slug to postId does not run which means `get_post` will not
+	 * behave as expected.
+	 *
+	 * The function will continue to delegate to the parent implementation
+	 * if the $id argument is ID-based, thereby ensuring backwards
+	 * compatbility.
+	 *
+	 * It may be possible to remove this implemenation in future releases.
+	 *
+	 * See: https://github.com/WordPress/gutenberg/pull/43703.
+	 *
+	 * @param string $id the slug of the Navigation post.
+	 * @return WP_Post|null
+	 */
+	protected function get_post( $id ) {
+
+		// Handle ID based $id param.
+		if ( is_numeric( $id ) ) {
+			return parent::get_post( $id );
+		}
+
+		// For string based $id the argument is a "slug".
+		// Lookup Post using `post_name` query.
+		$slug = $id;
+
+		$args = array(
+			'name'                   => $slug,
+			'post_type'              => 'wp_navigation',
+			'nopaging'               => true,
+			'posts_per_page'         => '1',
+			'update_post_term_cache' => false,
+			'no_found_rows'          => true,
+		);
+
+		// Query for the Navigation Post by slug (post_name).
+		$query = new WP_Query( $args );
+
+		if ( empty( $query->posts ) ) {
+			return new WP_Error(
+				'rest_post_not_found',
+				__( 'No navigation found.' ),
+				array( 'status' => 404 )
+			);
+		}
+
+		return $query->posts[0];
+	}
+}

lib/compat/wordpress-6.1/rest-api.php

@@ -93,3 +93,86 @@ function gutenberg_register_has_archive_on_post_types_endpoint() {
 	);
 }
 add_action( 'rest_api_init', 'gutenberg_register_has_archive_on_post_types_endpoint' );
+
+/**
+ * Use custom REST API Controller for Navigation Posts
+ *
+ * @param array $args the post type arguments.
+ * @return array the filtered post type arguments with the new REST Controller set.
+ */
+function gutenberg_update_navigation_rest_controller( $args, $post_type ) {
+	if ( in_array( $post_type, array( 'wp_navigation' ), true ) ) {
+		// Original set in
+		// https://github.com/WordPress/wordpress-develop/blob/6cbed78c94b9d8c6a9b4c8b472b88ee0cd56528c/src/wp-includes/post.php#L528.
+		$args['rest_controller_class'] = 'Gutenberg_REST_Navigation_Controller';
+	}
+	return $args;
+}
+add_filter( 'register_post_type_args', 'gutenberg_update_navigation_rest_controller', 10, 2 );
+
+function gutenberg_transform_slug_to_post_id( $response, $handler, WP_REST_Request $request ) {
+
+	$route = rest_get_route_for_post_type_items( 'wp_navigation' );
+
+	// Ignore non-Navigation REST API requests.
+	if ( ! str_starts_with( $request->get_route(), $route ) ) {
+		return $response;
+	}
+
+	// Get the slug from the request **URL** (not the request body).
+	// PUT requests will have a param of `slug` in both the URL and (potentially)
+	// in the body. In all cases only the slug in the URL should be mapped to a
+	// postId in order that the correct post to be updated can be retrived.
+	// The `slug` within the body should be preserved "as is".
+	$slug = isset( $request->get_url_params()['slug'] ) ? $request->get_url_params()['slug'] : null;
+
+	// If no slug provided assume ID and continue as normal.
+	if ( empty( $slug ) ) {
+		return $response;
+	}
+
+	$args = array(
+		'name'                   => $slug, // query by slug
+		'post_type'              => 'wp_navigation',
+		'nopaging'               => true,
+		'posts_per_page'         => '1',
+		'update_post_term_cache' => false,
+		'no_found_rows'          => true,
+	);
+
+	// Query for the Navigation Post by slug (post_name).
+	$query = new WP_Query( $args );
+
+	if ( empty( $query->posts ) ) {
+		return new WP_Error(
+			'rest_post_not_found',
+			__( 'No navigation found.' ),
+			array( 'status' => 404 )
+		);
+	}
+
+	// Set the post ID based on the slug.
+	$request['id'] = $query->posts[0]->ID;
+
+	return $response;
+}
+add_filter( 'rest_request_before_callbacks', 'gutenberg_transform_slug_to_post_id', 10, 3 );
+
+function gutenberg_update_navigation_rest_route_for_post( $route, WP_Post $post ) {
+
+	if ( $post->post_type !== 'wp_navigation' ) {
+		return $route;
+	}
+
+	$post_type_route = rest_get_route_for_post_type_items( $post->post_type );
+
+	if ( ! $post_type_route ) {
+		return '';
+	}
+
+	// Replace Post ID in route with Post "Slug" (post_name).
+	return sprintf( '%s/%s', $post_type_route, $post->post_name );
+}
+
+
+add_filter( 'rest_route_for_post', 'gutenberg_update_navigation_rest_route_for_post', 10, 2 );

lib/load.php

@@ -47,6 +47,7 @@ function gutenberg_is_experiment_enabled( $name ) {
 	// WordPress 6.1 compat.
 	require_once __DIR__ . '/compat/wordpress-6.1/class-gutenberg-rest-block-patterns-controller.php';
 	require_once __DIR__ . '/compat/wordpress-6.1/class-gutenberg-rest-templates-controller.php';
+	require_once __DIR__ . '/compat/wordpress-6.1/class-gutenberg-rest-navigation-controller.php';
 	require_once __DIR__ . '/compat/wordpress-6.1/rest-api.php';
 
 	// Experimental.

packages/block-library/src/navigation/block.json

@@ -11,6 +11,9 @@
 		"ref": {
 			"type": "number"
 		},
+		"slug": {
+			"type": "string"
+		},
 		"textColor": {
 			"type": "string"
 		},

packages/block-library/src/navigation/constants.js

@@ -0,0 +1,2 @@
+export const DEFAULT_ENTITY_KIND = 'root';
+export const DEFAULT_ENTITY_TYPE = 'navigation';