+ /**
+ * Get the post, if the ID is valid.
+ *
+ * @since 4.7.2
+ *
+ * @param int $id Supplied ID.
+ * @return WP_Post|WP_Error Post object if ID is valid, WP_Error otherwise.
+ */
+ protected function get_post( $id ) {
+ $error = new WP_Error( 'rest_post_invalid_id', __( 'Invalid post ID.' ), array( 'status' => 404 ) );
+ if ( (int) $id <= 0 ) {
+ return $error;
+ }
+
+ $post = get_post( (int) $id );
+ if ( empty( $post ) || empty( $post->ID ) || $this->post_type !== $post->post_type ) {
+ return $error;
+ }
+
+ return $post;
+ }
+