diff -r c7c34916027a -r 177826044cd9 wp/wp-includes/rest-api/search/class-wp-rest-search-handler.php
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/wp/wp-includes/rest-api/search/class-wp-rest-search-handler.php	Mon Oct 14 18:28:13 2019 +0200
@@ -0,0 +1,97 @@
+<?php
+/**
+ * REST API: WP_REST_Search_Handler class
+ *
+ * @package WordPress
+ * @subpackage REST_API
+ * @since 5.0.0
+ */
+
+/**
+ * Core base class representing a search handler for an object type in the REST API.
+ *
+ * @since 5.0.0
+ */
+abstract class WP_REST_Search_Handler {
+
+	/**
+	 * Field containing the IDs in the search result.
+	 */
+	const RESULT_IDS = 'ids';
+
+	/**
+	 * Field containing the total count in the search result.
+	 */
+	const RESULT_TOTAL = 'total';
+
+	/**
+	 * Object type managed by this search handler.
+	 *
+	 * @since 5.0.0
+	 * @var string
+	 */
+	protected $type = '';
+
+	/**
+	 * Object subtypes managed by this search handler.
+	 *
+	 * @since 5.0.0
+	 * @var array
+	 */
+	protected $subtypes = array();
+
+	/**
+	 * Gets the object type managed by this search handler.
+	 *
+	 * @since 5.0.0
+	 *
+	 * @return string Object type identifier.
+	 */
+	public function get_type() {
+		return $this->type;
+	}
+
+	/**
+	 * Gets the object subtypes managed by this search handler.
+	 *
+	 * @since 5.0.0
+	 *
+	 * @return array Array of object subtype identifiers.
+	 */
+	public function get_subtypes() {
+		return $this->subtypes;
+	}
+
+	/**
+	 * Searches the object type content for a given search request.
+	 *
+	 * @since 5.0.0
+	 *
+	 * @param WP_REST_Request $request Full REST request.
+	 * @return array Associative array containing an `WP_REST_Search_Handler::RESULT_IDS` containing
+	 *               an array of found IDs and `WP_REST_Search_Handler::RESULT_TOTAL` containing the
+	 *               total count for the matching search results.
+	 */
+	abstract public function search_items( WP_REST_Request $request );
+
+	/**
+	 * Prepares the search result for a given ID.
+	 *
+	 * @since 5.0.0
+	 *
+	 * @param int   $id     Item ID.
+	 * @param array $fields Fields to include for the item.
+	 * @return array Associative array containing all fields for the item.
+	 */
+	abstract public function prepare_item( $id, array $fields );
+
+	/**
+	 * Prepares links for the search result of a given ID.
+	 *
+	 * @since 5.0.0
+	 *
+	 * @param int $id Item ID.
+	 * @return array Links for the given item.
+	 */
+	abstract public function prepare_item_links( $id );
+}