vue-wp/plugins/cia-endpoints/includes/class.make-search.php

<?php
// include('formats.php');

class Make_Search_Endpoint extends WP_REST_Controller {
    function make_args($request) {
        $args = [
            'post_status'     => ['publish'],
            'posts_per_page'  => -1,
            'page'            => 1,
            'relevanssi'      => true,
            'post_type' => [
                'artist',
                'episode',
                'event',
                'exhibition',
                'guide',
                'object',
                'publication',
                'technique',
                'short',
                'post',
                'page'
            ]
        ];
        // Get parameters from request,
        // /?limit=<num>&?orderby=<str>&?order=<str>
        $params = $request->get_params();
        if(intval($params['limit']) > 0) {
            $args['posts_per_page'] = intval($params['limit']);
        }
        if(intval($params['p']) > 1) {
            $args['page'] = intval($params['p']);
            $args['offset'] = ($args['page'] * $args['posts_per_page']) - $args['posts_per_page'];
        }
        if($params['s']) {
            $args['s'] = $params['s'];
        }
        
        return $args;
    }
    /**
     * Register the routes for the objects of the controller.
     */
    public function register_custom_route($route) {
        $version = '2';
        $namespace = 'craft/v' . $version;

        register_rest_route( $namespace, '/' . $route, [
            array(
                'methods'  => WP_REST_Server::READABLE,
                'callback' => array( $this, 'get_results' )
            ),
        ]);
    }
    public function get_results( $request ) {
        // https://www.relevanssi.com/user-manual/functions/relevanssi_do_query/
        $q = new WP_Query($this->make_args($request));
        $found_posts = relevanssi_do_query( $q );
        return new WP_REST_Response( $this->prepare_items_for_reponse($found_posts), 200 );
    }
    public function prepare_items_for_reponse( $items ) {
        $collection = [];
        forEach( $items as $item ) {
            $formatted = default_post_format( $item, false );
            $formatted[hero] = get_post_meta( $item->ID, 'hero_header', true );
            array_push($collection, $formatted);
        }
        return $collection;
    }
}

add_filter( 'relevanssi_query_filter', function( $query ) {
    global $wp_query;
    if ( isset( $wp_query->query_vars['orderby'] ) && 'post_date' === $wp_query->query_vars['orderby'] ) {
        $query = str_replace( 'ORDER BY tf', 'ORDER BY relevanssi.doc', $query );
    }
    return $query;
}, 11 );
?>