template.php

<?php

/**
 * Override or insert variables into the page templates.
 *
 * @param $variables
 *   An array of variables to pass to the theme template.
 */
function clean_liquid_preprocess_page(&$variables) {
  if (isset($variables['attributes_array']['class'])) {
    $variables['attributes_array']['class'] = $variables['body_classes'] .' '. $variables['attributes_array']['class'];
  }
  else {
    $variables['attributes_array']['class'] = $variables['body_classes'];
  }

  if (!empty($variables['skip_link']) || !empty($variables['primary_links_themed']) || !empty($variables['secondary_links_themed']) || !empty($variables['breadcrumb'])) {
    $variables['navigation'] = TRUE;
    $variables['attributes_array']['class'] .= ' with-navigation';
  }
  else {
    $variables['navigation'] = FALSE;
  }
}