facetwp check specifc filters in use

script.js

(function($) {
    $(document).on('facetwp-loaded', function() {
        var facets_in_use = function() {
            var in_use = false;
            var checking = ["who", "what", "where", "when"];
            $.each(FWP.facets, function(name, val) {
                if (0 < val.length && $.inArray( name, checking ) > -1) {
                    in_use = true;
                    return false; // exit loop
                }
            });
            return in_use;
        }
        if ( facets_in_use() ) {
            $( '.filter-trip-style' ).addClass('in-use');
        } else {
            $( '.filter-trip-style' ).removeClass('in-use');
        }
    });
})(jQuery);