REST API: new endpoint to fetch post counts by post status

backport-changelog/6.8/7773.md

@@ -0,0 +1,3 @@
+https://github.com/WordPress/wordpress-develop/pull/7773
+
+* https://github.com/WordPress/gutenberg/pull/66294

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

@@ -0,0 +1,190 @@
+<?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 ( empty( $post_type ) ) {
+			return new WP_Error(
+				'rest_invalid_post_type',
+				__( 'Invalid post type.' ),
+				array( 'status' => 404 )
+			);
+		}
+
+		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 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 );
+		$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();
+
+		if ( ! empty( $item ) ) {
+			/*
+			 * 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( $item->$status ) ) {
+					$data[ $status ] = (int) $item->$status;
+				}
+			}
+		}
+
+		$context = ! empty( $request['context'] ) ? $request['context'] : 'view';
+		$data    = $this->add_additional_fields_to_object( $data, $request );
+		$data    = $this->filter_response_by_context( $data, $context );
+
+		return rest_ensure_response( $data );
+	}
+
+	/**
+	 * 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 );
+		}
+
+		/*
+		 * The fields comprise all non-internal post stati,
+		 * including any custom statuses that may be registered.
+		 * 'trash' is an exception, so if it exists, it is added separately.
+		 * The caveat is that all custom post statuses
+		 * must be registered at the highest priority, otherwise
+		 * the endpoint will not return them.
+		 */
+		$post_statuses = get_post_stati( array( 'internal' => false ) );
+
+		if ( get_post_status_object( 'trash' ) ) {
+			$post_statuses[] = 'trash';
+		}
+		$schema_properties = array();
+		foreach ( $post_statuses as $post_status ) {
+			$schema_properties[ $post_status ] = array(
+				// translators: %s: Post status.
+				'description' => sprintf( __( 'The number of posts with the status %s.' ), $post_status ),
+				'type'        => 'integer',
+				'context'     => array( 'view', 'edit' ),
+				'readonly'    => true,
+			);
+		}
+
+		$schema = array(
+			'$schema'    => 'http://json-schema.org/draft-04/schema#',
+			'title'      => 'post-counts',
+			'type'       => 'object',
+			'properties' => $schema_properties,
+		);
+
+		$this->schema = $schema;
+
+		return $this->add_additional_fields_schema( $this->schema );
+	}
+}

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

@@ -87,3 +87,13 @@ function gutenberg_add_default_template_types_to_index( WP_REST_Response $respon
 }
 
 add_filter( 'rest_index', 'gutenberg_add_default_template_types_to_index' );
+
+/**
+ * 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 +46,7 @@ function gutenberg_is_experiment_enabled( $name ) {
 	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-hierarchical-sort.php';
+	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.