Turba::getColumns PHP Method

    public static function getColumns()
    {
        $columns = array();
        $lines = explode("\n", $GLOBALS['prefs']->getValue('columns'));
        foreach ($lines as $line) {
            $line = trim($line);
            if ($line) {
                $cols = explode("\t", $line);
                if (count($cols) > 1) {
                    $source = array_splice($cols, 0, 1);
                    $columns[$source[0]] = array();
                    foreach ($cols as $col) {
                        if ($col == '__tags' || isset($GLOBALS['cfgSources'][$source[0]]['map'][$col])) {
                            $columns[$source[0]][] = $col;
                        }
                    }
                }
            }
        }
        return $columns;
    }

 /**
  * Changes category columns to tag columns in the browse view.
  */
 protected function _upgradeColumnsPref()
 {
     $newColumns = array();
     foreach (Turba::getColumns() as $source => $columns) {
         if (($pos = array_search('category', $columns)) !== false) {
             array_splice($columns, $pos, 1, '__tags');
         }
         array_unshift($columns, $source);
         $newColumns[] = implode("\t", $columns);
     }
     $GLOBALS['prefs']->setValue('columns', implode("\n", $newColumns));
 }