REST API: add WP_REST_Posts_Controller route to fetch page counts

backport-changelog/6.8/7773.md

@@ -0,0 +1,3 @@
+https://github.com/WordPress/wordpress-develop/pull/7773
+
+* https://github.com/WordPress/gutenberg/pull/67719

lib/compat/wordpress-6.8/class-gutenberg-rest-posts-controller-6-8.php

@@ -0,0 +1,117 @@
+<?php
+/**
+ * REST API: Gutenberg_REST_Posts_Controller_6_8 class
+ *
+ * @package gutenberg
+ */
+
+/**
+ * Gutenberg_REST_Posts_Controller_6_8 class
+ *
+ * Adds a /counts route to return total posts count.
+ */
+class Gutenberg_REST_Posts_Controller_6_8 extends Gutenberg_REST_Posts_Controller_6_7 {
+	/**
+	 * Registers the routes for attachments.
+	 *
+	 * @see register_rest_route()
+	 */
+	public function register_routes() {
+		parent::register_routes();
+
+		register_rest_route(
+			$this->namespace,
+			'/' . $this->rest_base . '/count',
+			array(
+				array(
+					'methods'             => WP_REST_Server::READABLE,
+					'callback'            => array( $this, 'get_count' ),
+					'permission_callback' => array( $this, 'get_count_permissions_check' ),
+				),
+				'schema' => array( $this, 'get_count_schema' ),
+			)
+		);
+	}
+
+	/**
+	 * Retrieves post counts for the post type.
+	 *
+	 * @since 6.8.0
+	 *
+	 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
+	 */
+	public function get_count() {
+		$counts = wp_count_posts( $this->post_type );
+		$data   = array();
+
+		if ( ! empty( $counts ) ) {
+			/*
+			 * The fields comprise all non-internal post statuses,
+			 * including any custom statuses that may be registered.
+			 * 'trash' is an exception, so if it exists, it is added separately.
+			 */
+			$post_stati = get_post_stati( array( 'internal' => false ) );
+
+			if ( get_post_status_object( 'trash' ) ) {
+				$post_stati[] = 'trash';
+			}
+			// Include all public statuses in the response if there is a count.
+			foreach ( $post_stati as $status ) {
+				if ( isset( $counts->$status ) ) {
+					$data[ $status ] = (int) $counts->$status;
+				}
+			}
+		}
+		return rest_ensure_response( $data );
+	}
+
+	/**
+	 * Checks if a given request has access to read post counts.
+	 *
+	 * @since 6.8.0
+	 *
+	 * @return true|WP_Error True if the request has read access, WP_Error object otherwise.
+	 */
+	public function get_count_permissions_check() {
+		$post_type = get_post_type_object( $this->post_type );
+
+		if ( ! current_user_can( $post_type->cap->read ) ) {
+			return new WP_Error(
+				'rest_cannot_read',
+				__( 'Sorry, you are not allowed to read post counts for this post type.' ),
+				array( 'status' => rest_authorization_required_code() )
+			);
+		}
+
+		return true;
+	}
+
+	/**
+	 * Retrieves the post counts schema, conforming to JSON Schema.
+	 *
+	 * @since 6.8.0
+	 *
+	 * @return array Item schema data.
+	 */
+	public function get_count_schema() {
+		return array(
+			'$schema'              => 'http://json-schema.org/draft-04/schema#',
+			'title'                => 'post-counts',
+			'type'                 => 'object',
+			/*
+			 * Use a pattern matcher for post status keys.
+			 * This allows for custom post statuses to be included,
+			 * which can be registered after the schema is generated.
+			 */
+			'patternProperties'    => array(
+				'^\w+$' => array(
+					'description' => __( 'The number of posts for a given status.' ),
+					'type'        => 'integer',
+					'context'     => array( 'view', 'edit', 'embed' ),
+					'readonly'    => true,
+				),
+			),
+			'additionalProperties' => false,
+		);
+	}
+}

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

@@ -21,6 +21,30 @@ function gutenberg_add_post_type_rendering_mode() {
 }
 add_action( 'rest_api_init', 'gutenberg_add_post_type_rendering_mode' );
 
+if ( ! function_exists( 'gutenberg_rest_posts_controller_6_8' ) ) {
+	function gutenberg_rest_posts_controller_6_8( $args, $post_type ) {
+		/*
+		 * This was carried over from the Gutenberg_REST_Posts_Controller_6_7 compatibility class,
+		 * so when that is deleted, this condition block can be removed.
+		 */
+		if ( ! empty( $args['supports'] ) && in_array( 'post-formats', $args['supports'], true ) ) {
+			$args['rest_controller_class'] = 'Gutenberg_REST_Posts_Controller_6_8';
+		}
+
+		/*
+		 * Gutenberg only supports page counts for now.
+		 * In the Core sync, WP_REST_Posts_Controller will be extended
+		 * to support this for all post types that use/inherit from it.
+		 */
+		if ( 'page' === $post_type ) {
+			$args['rest_controller_class'] = 'Gutenberg_REST_Posts_Controller_6_8';
+		}
+		return $args;
+	}
+}
+
+add_filter( 'register_post_type_args', 'gutenberg_rest_posts_controller_6_8', 10, 2 );
+
 // When querying terms for a given taxonomy in the REST API, respect the default
 // query arguments set for that taxonomy upon registration.
 function gutenberg_respect_taxonomy_default_args_in_rest_api( $args ) {

lib/load.php

@@ -45,6 +45,7 @@ function gutenberg_is_experiment_enabled( $name ) {
 	require __DIR__ . '/compat/wordpress-6.8/block-comments.php';
 	require __DIR__ . '/compat/wordpress-6.8/class-gutenberg-rest-comment-controller-6-8.php';
 	require __DIR__ . '/compat/wordpress-6.8/class-gutenberg-rest-post-types-controller-6-8.php';
+	require __DIR__ . '/compat/wordpress-6.8/class-gutenberg-rest-posts-controller-6-8.php';
 	require __DIR__ . '/compat/wordpress-6.8/rest-api.php';
 
 	// Plugin specific code.
@@ -91,7 +92,6 @@ function gutenberg_is_experiment_enabled( $name ) {
 require __DIR__ . '/compat/wordpress-6.7/script-modules.php';
 require __DIR__ . '/compat/wordpress-6.7/class-wp-block-templates-registry.php';
 require __DIR__ . '/compat/wordpress-6.7/compat.php';
-require __DIR__ . '/compat/wordpress-6.7/post-formats.php';
 
 // WordPress 6.8 compat.
 require __DIR__ . '/compat/wordpress-6.8/preload.php';