First commit: create a new endpoint to retrieve post counts by status.

lib/compat/wordpress-6.8/class-gutenberg-rest-post-counts-controller.php

@@ -0,0 +1,217 @@
+<?php
+/**
+ * REST API: Gutenberg_REST_Post_Counts_Controller class
+ *
+ * @since 6.8.0
+ *
+ * @package gutenberg
+ * @subpackage REST_API
+ */
+
+/**
+ * Core class used to return post counts by post type via the REST API.
+ *
+ * @since 6.8.0
+ *
+ * @see WP_REST_Controller
+ */
+class Gutenberg_REST_Post_Counts_Controller extends WP_REST_Controller {
+
+	/**
+	 * Constructor.
+	 */
+	public function __construct() {
+		$this->namespace = 'wp/v2';
+		$this->rest_base = 'counts';
+	}
+
+	/**
+	 * Registers the routes for post counts.
+	 *
+	 * @since 6.8.0
+	 *
+	 * @see register_rest_route()
+	 */
+	public function register_routes() {
+		register_rest_route(
+			$this->namespace,
+			'/' . $this->rest_base . '/(?P<post_type>[\w-]+)',
+			array(
+				'args' => array(
+					'post_type' => array(
+						'description' => __( 'An alphanumeric identifier for the post type.' ),
+						'type'        => 'string',
+					),
+				),
+				array(
+					'methods'             => WP_REST_Server::READABLE,
+					'callback'            => array( $this, 'get_item' ),
+					'permission_callback' => array( $this, 'get_item_permissions_check' ),
+					'args'                => array(
+						'context' => $this->get_context_param( array( 'default' => 'view' ) ),
+					),
+				),
+				'schema' => array( $this, 'get_public_item_schema' ),
+			)
+		);
+	}
+
+	/**
+	 * Checks if a given request has access to read post counts.
+	 *
+	 * @since 6.8.0
+	 *
+	 * @param WP_REST_Request $request Full details about the request.
+	 * @return true|WP_Error True if the request has read access, WP_Error object otherwise.
+	 */
+	public function get_item_permissions_check( $request ) {
+		$post_type = get_post_type_object( $request['post_type'] );
+
+		if ( ! $post_type ) {
+			return new WP_Error(
+				'rest_invalid_post_type',
+				__( 'Invalid post type.' ),
+				array( 'status' => 404 )
+			);
+		}
+
+		if ( ! current_user_can( $post_type->cap->edit_posts ) ) {
+			return new WP_Error(
+				'rest_cannot_read',
+				__( 'Sorry, you are not allowed to read post counts for this post type.' ),
+				array( 'status' => rest_authorization_required_code() )
+			);
+		}
+
+		return true;
+	}
+
+	/**
+	 * Retrieves post counts for a specific post type.
+	 *
+	 * @since 6.8.0
+	 *
+	 * @param WP_REST_Request $request Full details about the request.
+	 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
+	 */
+	public function get_item( $request ) {
+		$post_type = $request['post_type'];
+		$counts = wp_count_posts( $post_type );
+
+		if ( ! $counts ) {
+			return new WP_Error(
+				'rest_post_counts_error',
+				__( 'Could not retrieve post counts.' ),
+				array( 'status' => 500 )
+			);
+		}
+
+		$data = $this->prepare_item_for_response( $counts, $request );
+		return rest_ensure_response( $data );
+	}
+
+	/**
+	 * Prepares post counts for response.
+	 *
+	 * @since 6.8.0
+	 *
+	 * @param object          $item    Post counts data.
+	 * @param WP_REST_Request $request Request object.
+	 * @return WP_REST_Response Response object.
+	 */
+	public function prepare_item_for_response( $item, $request ) {
+		$data = array();
+		$fields = $this->get_fields_for_response( $request );
+
+		foreach ( $fields as $field ) {
+			if ( property_exists( $item, $field ) ) {
+				$data[ $field ] = intval( $item->$field );
+			}
+		}
+
+		$context = ! empty( $request['context'] ) ? $request['context'] : 'view';
+		$data = $this->add_additional_fields_to_object( $data, $request );
+		$data = $this->filter_response_by_context( $data, $context );
+
+		$response = rest_ensure_response( $data );
+
+		/**
+		 * Filters post type counts data for the REST API.
+		 * Allows modification of the post type counts data right before it is returned.
+		 *
+		 * @since 6.8.0
+		 *
+		 * @param WP_REST_Response $response The response object.
+		 * @param object           $item     The original post counts object.
+		 * @param WP_REST_Request  $request  Request used to generate the response.
+		 */
+		return apply_filters( 'rest_prepare_post_counts', $response, $item, $request );
+	}
+
+	/**
+	 * Retrieves the post counts schema, conforming to JSON Schema.
+	 *
+	 * @since 6.8.0
+	 *
+	 * @return array Item schema data.
+	 */
+	public function get_item_schema() {
+		if ( $this->schema ) {
+			return $this->add_additional_fields_schema( $this->schema );
+		}
+
+		$schema = array(
+			'$schema'    => 'http://json-schema.org/draft-04/schema#',
+			'title'      => 'post-counts',
+			'type'       => 'object',
+			'properties' => array(
+				'publish'    => array(
+					'description' => __( 'The number of published posts.' ),
+					'type'        => 'integer',
+					'context'     => array( 'view', 'edit' ),
+					'readonly'    => true,
+				),
+				'future'     => array(
+					'description' => __( 'The number of future scheduled posts.' ),
+					'type'        => 'integer',
+					'context'     => array( 'view', 'edit' ),
+					'readonly'    => true,
+				),
+				'draft'      => array(
+					'description' => __( 'The number of draft posts.' ),
+					'type'        => 'integer',
+					'context'     => array( 'view', 'edit' ),
+					'readonly'    => true,
+				),
+				'pending'    => array(
+					'description' => __( 'The number of pending posts.' ),
+					'type'        => 'integer',
+					'context'     => array( 'view', 'edit' ),
+					'readonly'    => true,
+				),
+				'private'    => array(
+					'description' => __( 'The number of private posts.' ),
+					'type'        => 'integer',
+					'context'     => array( 'view', 'edit' ),
+					'readonly'    => true,
+				),
+				'trash'      => array(
+					'description' => __( 'The number of trashed posts.' ),
+					'type'        => 'integer',
+					'context'     => array( 'view', 'edit' ),
+					'readonly'    => true,
+				),
+				'auto-draft' => array(
+					'description' => __( 'The number of auto-draft posts.' ),
+					'type'        => 'integer',
+					'context'     => array( 'view', 'edit' ),
+					'readonly'    => true,
+				),
+			),
+		);
+
+		$this->schema = $schema;
+
+		return $this->add_additional_fields_schema( $this->schema );
+	}
+}

lib/compat/wordpress-6.8/rest-api.php

@@ -0,0 +1,22 @@
+<?php
+/**
+ * PHP and WordPress configuration compatibility functions for the Gutenberg
+ * editor plugin changes related to REST API.
+ *
+ * @package gutenberg
+ */
+
+if ( ! defined( 'ABSPATH' ) ) {
+	die( 'Silence is golden.' );
+}
+
+/**
+ * Registers the Post Counts REST API routes.
+ */
+function gutenberg_register_post_counts_routes() {
+	$post_counts_controller = new Gutenberg_REST_Post_Counts_Controller();
+	$post_counts_controller->register_routes();
+}
+
+add_action( 'rest_api_init', 'gutenberg_register_post_counts_routes' );
+

lib/load.php

@@ -46,6 +46,10 @@ function gutenberg_is_experiment_enabled( $name ) {
 	require __DIR__ . '/compat/wordpress-6.7/class-gutenberg-rest-server.php';
 	require __DIR__ . '/compat/wordpress-6.7/rest-api.php';
 
+	// WordPress 6.8 compat.
+	require __DIR__ . '/compat/wordpress-6.8/class-gutenberg-rest-post-counts-controller.php';
+	require __DIR__ . '/compat/wordpress-6.8/rest-api.php';
+
 	// Plugin specific code.
 	require_once __DIR__ . '/class-wp-rest-global-styles-controller-gutenberg.php';
 	require_once __DIR__ . '/class-wp-rest-edit-site-export-controller-gutenberg.php';