WordPress Plugin: Taxonomy WP REST Search for the WordPress Block Editor (Gutenberg)

taxonomy-wp-rest-search.php

<?php
/**
 * Plugin Name:  Taxonomy WP REST Search
 * Plugin URI:
 * Description:  Taxonomy WP REST Search for the WordPress Block Editor (Gutenberg)
 * Author:       Johannes Kinast <johannes@travel-dealz.de>
 * Author URI:   https://go-around.de
 * Version:     1.0.0
 */
namespace Taxonomy_WP_REST_Search;

use WP_REST_Search_Handler;
use WP_REST_Request;
use WP_REST_Search_Controller;
use WP_Term_Query;

function wp_rest_search_handlers( $handlers ) {

	// Add Taxonomy Handler
	$handlers[] = new WP_REST_Taxonomy_Search_Handler();

	return $handlers;
}
add_filter( 'wp_rest_search_handlers', __NAMESPACE__ . '\wp_rest_search_handlers' );

function change_search_type( $result, $server, $request ) {

	if ( '/wp/v2/search' !== $request->get_route() ) {
		return $result;
	}

	$supported = [
		'tax' => 'taxonomy',
		'ter' => 'taxonomy',
	];

	$matches = [];
	preg_match( '/^-(\w{2,3}) (.*)/', $request->get_param( 'search' ), $matches );
	if ( 3 === count( $matches ) && isset( $supported[$matches[1]] ) ) {

		$request->set_param( 'type', $supported[$matches[1]] );
		$request->set_param( 'search', $matches[2] );

	}

	return $result;
}
add_filter( 'rest_pre_dispatch', __NAMESPACE__ . '\change_search_type', 10, 3 );

class WP_REST_Taxonomy_Search_Handler extends WP_REST_Search_Handler {

	public function __construct() {
		$this->type = 'taxonomy';

		$this->subtypes = get_taxonomies( [
			'show_ui' => true,
			'public' => true,
		] );
	}

	/**
	 * Searches the object type content for a given search request.
	 *
	 *
	 * @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.
	 */
	public function search_items( WP_REST_Request $request ) {
		// Get the taxonomy types to search for the current request.
		$taxonomy_types = $request[ WP_REST_Search_Controller::PROP_SUBTYPE ];
		if ( in_array( WP_REST_Search_Controller::TYPE_ANY, $taxonomy_types, true ) ) {
			$taxonomy_types = $this->subtypes;
		}

		$offset = ( $request['page'] - 1 ) * $request['per_page'];

		$query_args = array(
			'taxonomy'           	=> $taxonomy_types,
			// Replace paged with offset
			//'paged'               	=> (int) $request['page'],
			'number'      			=> (int) $request['per_page'],
			'offset'				=> (int) $offset,
			'fields'              	=> 'ids',
			'hide_empty'			=> false,
		);

		if ( ! empty( $request['search'] ) ) {
			$query_args['search'] = $request['search'];
		}

		$query     = new WP_Term_Query();
		$found_ids = $query->query( $query_args );

		$total = $offset + count( $found_ids );
		if ( count( $found_ids ) === (int) $request['per_page'] ) {
			$total = $total + 1;
		}

		return [
			self::RESULT_IDS   => $found_ids,
			self::RESULT_TOTAL => $total,
		];
	}

	/**
	 * Prepares the search result for a given ID.
	 *
	 *
	 * @param int   $id     Item ID.
	 * @param array $fields Fields to include for the item.
	 * @return array Associative array containing all fields for the item.
	 */
	public function prepare_item( $id, array $fields ) {
		$term = get_term( $id );

		$data = [];

		if ( in_array( WP_REST_Search_Controller::PROP_ID, $fields, true ) ) {
			$data[ WP_REST_Search_Controller::PROP_ID ] = (int) $term->term_id;
		}
		if ( in_array( WP_REST_Search_Controller::PROP_TITLE, $fields, true ) ) {
			$data[ WP_REST_Search_Controller::PROP_TITLE ] = $term->name;
		}
		if ( in_array( WP_REST_Search_Controller::PROP_URL, $fields, true ) ) {
			$data[ WP_REST_Search_Controller::PROP_URL ] = get_term_link( $term );
		}
		if ( in_array( WP_REST_Search_Controller::PROP_TYPE, $fields, true ) ) {
			$data[ WP_REST_Search_Controller::PROP_TYPE ] = $this->type;
		}
		if ( in_array( WP_REST_Search_Controller::PROP_SUBTYPE, $fields, true ) ) {
			$data[ WP_REST_Search_Controller::PROP_SUBTYPE ] = get_taxonomy( $term->taxonomy )->labels->singular_name;
		}

		return $data;
	}

	/**
	 * Prepares links for the search result of a given ID.
	 *
	 *
	 * @param int $id Item ID.
	 * @return array Links for the given item.
	 */
	public function prepare_item_links( $id ) {

		$links = [];
		return $links;

	}
}