Wallmander\ElasticsearchIndexer\Model\Query\WpConverter::argTaxQuery PHP Method

    public static function argTaxQuery(Query $query, $value, &$q)
    {
        $currentValue = $value;
        $function = function (Query $query) use(&$currentValue, &$function) {
            foreach ($currentValue as $key => $tax) {
                if ($key === 'relation') {
                    continue;
                }
                if (!isset($tax[0]) || !is_array($tax[0])) {
                    // not nested
                    $include_children = !isset($tax['include_children']) || $tax['include_children'] != false;
                    $compare = empty($tax['operator']) ? 'in' : $tax['operator'];
                    $terms = $tax['terms'];
                    if (is_string($terms)) {
                        if (strpos($terms, '+') !== false) {
                            $terms = preg_split('/[+]+/', $terms);
                        } else {
                            $terms = preg_split('/[,]+/', $terms);
                        }
                    }
                    switch ($tax['field']) {
                        case 'term_id':
                            $query->where("terms.{$tax['taxonomy']}.term_id", $compare, $terms);
                            if ($include_children) {
                                $query->where("terms.{$tax['taxonomy']}.parent", $compare, $terms);
                            }
                            break;
                        case 'slug':
                            if ($include_children) {
                                $query->where("terms.{$tax['taxonomy']}.all_slugs", $compare, $terms);
                            } else {
                                $query->where("terms.{$tax['taxonomy']}.slug", $compare, $terms);
                            }
                            break;
                        case 'name':
                            // plugin exclusive feature.
                            $query->where("terms.{$tax['taxonomy']}.name", $compare, $terms);
                            break;
                    }
                } else {
                    // nested
                    $currentValue = $tax;
                    $query->bool($function, !empty($currentValue['relation']) ? $currentValue['relation'] : 'and');
                }
            }
        };
        $query->bool($function, !empty($value['relation']) ? $value['relation'] : 'and');
    }