Ticket #45677: 45677.10.diff

src/wp-includes/class-wp-post-type.php

@@ -335 +335 @@
          */
         public $rest_controller_class;
 
+        /**
+         * The controller instance for this post type's REST API endpoints.
+         *
+         * Lazily computed. Should be accessed using {@see WP_Post_Type::get_rest_controller()}.
+         *
+         * @since 5.3.0
+         * @var WP_REST_Controller $rest_controller
+         */
+        private $rest_controller;
+
         /**
          * Constructor.
          *
@@ -682 +692 @@
         public function remove_hooks() {
                 remove_action( 'future_' . $this->name, '_future_post_hook', 5 );
         }
+
+        /**
+         * Gets the REST API controller for this post type.
+         *
+         * Will only instantiate the controller class once per request.
+         *
+         * @since 5.3.0
+         *
+         * @return WP_REST_Controller|null The controller instance, or null if the post type
+         *                                 is set not to show in rest.
+         */
+        public function get_rest_controller() {
+                if ( ! $this->show_in_rest ) {
+                        return null;
+                }
+
+                $class = $this->rest_controller_class ? $this->rest_controller_class : WP_REST_Posts_Controller::class;
+
+                if ( ! class_exists( $class ) ) {
+                        return null;
+                }
+
+                if ( ! is_subclass_of( $class, WP_REST_Controller::class ) ) {
+                        return null;
+                }
+
+                if ( ! $this->rest_controller ) {
+                        $this->rest_controller = new $class( $this->name );
+                }
+
+                return $this->rest_controller;
+        }
 }

src/wp-includes/rest-api.php

@@ -192 +192 @@
  */
 function create_initial_rest_routes() {
         foreach ( get_post_types( array( 'show_in_rest' => true ), 'objects' ) as $post_type ) {
-                $class = ! empty( $post_type->rest_controller_class ) ? $post_type->rest_controller_class : 'WP_REST_Posts_Controller';
+                $controller = $post_type->get_rest_controller();
 
-                if ( ! class_exists( $class ) ) {
-                        continue;
-                }
-                $controller = new $class( $post_type->name );
-                if ( ! is_subclass_of( $controller, 'WP_REST_Controller' ) ) {
+                if ( ! $controller ) {
                         continue;
                 }
 

src/wp-includes/rest-api/endpoints/class-wp-rest-autosaves-controller.php

@@ -59 +59 @@
         public function __construct( $parent_post_type ) {
                 $this->parent_post_type = $parent_post_type;
                 $post_type_object       = get_post_type_object( $parent_post_type );
+                $parent_controller      = $post_type_object->get_rest_controller();
 
-                // Ensure that post type-specific controller logic is available.
-                $parent_controller_class = ! empty( $post_type_object->rest_controller_class ) ? $post_type_object->rest_controller_class : 'WP_REST_Posts_Controller';
+                if ( ! $parent_controller ) {
+                        $parent_controller = new WP_REST_Posts_Controller( $parent_post_type );
+                }
 
-                $this->parent_controller    = new $parent_controller_class( $post_type_object->name );
+                $this->parent_controller    = $parent_controller;
                 $this->revisions_controller = new WP_REST_Revisions_Controller( $parent_post_type );
                 $this->rest_namespace       = 'wp/v2';
                 $this->rest_base            = 'autosaves';

src/wp-includes/rest-api/endpoints/class-wp-rest-comments-controller.php

@@ -1592 +1592 @@
          * @return bool Whether post can be read.
          */
         protected function check_read_post_permission( $post, $request ) {
-                $posts_controller = new WP_REST_Posts_Controller( $post->post_type );
                 $post_type        = get_post_type_object( $post->post_type );
+                $posts_controller = $post_type->get_rest_controller();
+
+                // We need to specifically assert that the posts controller is a WP_REST_Posts_Controller instance,
+                // and not just check that we have a valid controller as we use Posts Controller specific methods.
+                if ( ! $posts_controller instanceof WP_REST_Posts_Controller ) {
+                        $posts_controller = new WP_REST_Posts_Controller( $post->post_type );
+                }
 
                 $has_password_filter = false;
 

src/wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php

@@ -16 +16 @@
  */
 class WP_REST_Posts_Controller extends WP_REST_Controller {
 
+        /**
+         * Instances of post type controllers keyed by post type.
+         *
+         * @since 5.3.0
+         * @var WP_REST_Controller[]
+         */
+        private static $post_type_controllers = array();
+
         /**
          * Post type.
          *

src/wp-includes/rest-api/endpoints/class-wp-rest-revisions-controller.php

@@ -49 +49 @@
          */
         public function __construct( $parent_post_type ) {
                 $this->parent_post_type  = $parent_post_type;
-                $this->parent_controller = new WP_REST_Posts_Controller( $parent_post_type );
                 $this->namespace         = 'wp/v2';
                 $this->rest_base         = 'revisions';
                 $post_type_object        = get_post_type_object( $parent_post_type );
                 $this->parent_base       = ! empty( $post_type_object->rest_base ) ? $post_type_object->rest_base : $post_type_object->name;
+                $this->parent_controller = $post_type_object->get_rest_controller();
+
+                if ( ! $this->parent_controller ) {
+                        $this->parent_controller = new WP_REST_Posts_Controller( $parent_post_type );
+                }
         }
 
         /**

tests/phpunit/tests/rest-api/rest-posts-controller.php

@@ -4526 +4526 @@
                 $this->assertNotEquals( '0000-00-00 00:00:00', get_post( $post->ID )->post_date_gmt );
         }
 
+        /**
+         * @ticket 45677
+         */
+        public function test_get_for_post_type_reuses_same_instance() {
+                $this->assertSame(
+                        get_post_type_object( 'post' )->get_rest_controller(),
+                        get_post_type_object( 'post' )->get_rest_controller()
+                );
+        }
+
+        /**
+         * @ticket 45677
+         */
+        public function test_get_for_post_type_returns_null_if_post_type_does_not_show_in_rest() {
+                register_post_type(
+                        'not_in_rest',
+                        array(
+                                'show_in_rest' => false,
+                        )
+                );
+
+                $this->assertNull( get_post_type_object( 'not_in_rest' )->get_rest_controller() );
+        }
+
+        /**
+         * @ticket 45677
+         */
+        public function test_get_for_post_type_returns_null_if_class_does_not_exist() {
+                register_post_type(
+                        'class_not_found',
+                        array(
+                                'show_in_rest'          => true,
+                                'rest_controller_class' => 'Class_That_Does_Not_Exist',
+                        )
+                );
+
+                $this->assertNull( get_post_type_object( 'class_not_found' )->get_rest_controller() );
+        }
+
+        /**
+         * @ticket 45677
+         */
+        public function test_get_for_post_type_returns_null_if_class_does_not_subclass_rest_controller() {
+                register_post_type(
+                        'invalid_class',
+                        array(
+                                'show_in_rest'          => true,
+                                'rest_controller_class' => 'WP_Post',
+                        ),
+                );
+
+                $this->assertNull( get_post_type_object( 'invalid_class' )->get_rest_controller() );
+        }
+
+        /**
+         * @ticket 45677
+         */
+        public function test_get_for_post_type_returns_posts_controller_if_custom_class_not_specified() {
+                register_post_type(
+                        'test',
+                        array(
+                                'show_in_rest' => true,
+                        )
+                );
+
+                $this->assertInstanceOf(
+                        WP_REST_Posts_Controller::class,
+                        get_post_type_object( 'test' )->get_rest_controller()
+                );
+        }
+
+        /**
+         * @ticket 45677
+         */
+        public function test_get_for_post_type_returns_provided_controller_class() {
+                $this->assertInstanceOf(
+                        WP_REST_Blocks_Controller::class,
+                        get_post_type_object( 'wp_block' )->get_rest_controller()
+                );
+        }
+
         public function tearDown() {
                 _unregister_post_type( 'private-post' );
                 _unregister_post_type( 'youseeme' );