FacetWP – add CSS class to active facets

(function($) {
  $(document).on('facetwp-loaded', function() {
    $.each(FWP.facets, function(name, vals) {
      if (FWP.facets[name].length > 0) {
        $('.facetwp-facet-' + name).addClass('is-active');
      }
      else {
        $('.facetwp-facet-' + name).removeClass('is-active');
      }
    });
  });
})(jQuery);