/**
 * Example function for a customised search, demonstrating usage of
 * the google_appliance_search() $options parameter
 *
 * @param $client
 *   Which front end to use (NULL for default)
 * @param $collection
 *   Which collection to search (NULL for default)
 * @param $terms
 *   One or more term ids (comma-separated list)
 * @param $types
 *   One or more content types (comma-separated list)
 * @param $keys
 *   Search string
 */
function example_search($client = NULL, $collection = NULL, $terms = NULL, $types = NULL, $keys = NULL) {
  $output = "";

  if (!isset($_POST['form_id'])) {
    $options = array();

    $requiredfields = array();
    $vocabs = taxonomy_get_vocabularies();
    foreach (explode(',', $terms) as $tid) {
      if ($term = taxonomy_get_term($tid)) {
        $category = google_appliance_sgml_id_name('category-'. strtolower($vocabs[$term->vid]->name));
        $requiredfields[] = $category .':'. rawurlencode($term->name);
      }
    }
    foreach (explode(',', $types) as $type) {
      $requiredfields[] = 'type:'. rawurlencode($type);
    }
    if ($requiredfields) {
      $options['requiredfields'] = implode('.', $requiredfields); //'.' == AND; '|' == OR
    }

    if ($options || $keys) {
      if ($results = google_appliance_search('search', $keys, $options, $collection, $client)) {
        $output .= theme('box', t('Search results'), theme('search_results', $results, 'google-appliance'));
      }
      else {
        $message = variable_get('google_appliance_errorcode_1', t('Your search yielded no results'));
      }
    }
  }
  return $output;
}