FacetWP - sort by average rating using the WP Job Manager Reviews plugin

functions.php

<?php
/**
 * Add a "Rating" sort option
 * 
 * @author David Nash <[email protected]>
 */
function custom_wpjmr_after_save_comment_review( $comment_id ) {
    $wpjmr = WP_Job_Manager_Reviews::instance();
    $wpjmr->review->save_rating_average_post_meta( $comment_id );
}
add_action( 'wpjmr_after_save_comment_review', custom_wpjmr_after_save_comment_review' );


function my_facetwp_sort_options( $options, $params ) {
    $options['rating'] = array(
        'label' => 'Rating',
        'query_args' => array(
            'orderby' => 'meta_value_num', // sort by numerical custom field
            'meta_key' => '_average_rating', // required when sorting by custom fields
            'order' => 'DESC', // descending order
        )
    );
    return $options;
}
add_filter( 'facetwp_sort_options', 'my_facetwp_sort_options', 10, 2 );