set taxonomy as class on node detail / set parent taxonomy term on term detail

template.php

function community_preprocess_html(&$vars) {
  // set thema_[tid] class when on node detail
  if(isset($vars['page']['content']['system_main']['nodes'])) {
    $node = reset($vars['page']['content']['system_main']['nodes']);
    if(isset($node['field_thema']['#items'][0]['tid'])){
     $vars['classes_array'][] = 'thema_' . $node['field_thema']['#items'][0]['tid']; 
    }
  }

  // set parent level thema_[tid] class on taxonomy detail
  if(arg(0) == 'taxonomy' && arg(1) == 'term') {
    $tid = (int)arg(2);
    $the_parents = taxonomy_get_parents($tid);
    foreach ($the_parents as $the_parent) {
      //kpr($the_parent);
      $vars['classes_array'][] = 'thema_' . $the_parent->tid;
    } 

  }

}