/**
 * Fetch a handler from the data cache.
 *
 * @param $table
 *   The name of the table this handler is from.
 * @param $field
 *   The name of the field this handler is from.
 * @param $key
 *   The type of handler. i.e, sort, field, argument, filter, relationship
 *
 * @return views_handler
 *   An instance of a handler object. May be views_handler_broken.
 */
function views_get_handler($table, $field, $key) {
  $data = views_fetch_data($table);
  if (isset($data[$field][$key])) {
    // Set up a default handler:
    if (empty($data[$field][$key]['handler'])) {
      $data[$field][$key]['handler'] = 'views_handler_' . $key;
    }
    return _views_prepare_handler($data[$field][$key], $data, $field);
  }
  // DEBUG -- identify missing handlers
  vpr("Missing handler: $table $field $key");
  $broken = array(
    'title' => t('Broken handler @table.@field', array('@table' => $table, '@field' => $field)),
    'handler' => 'views_handler_' . $key . '_broken',
    'table' => $table,
    'field' => $field,
  );
  return _views_create_handler($broken);
}