/** * Set value binder to use * * @param PHPExcel_Cell_IValueBinder $binder * @throws Exception */ public static function setValueBinder(PHPExcel_Cell_IValueBinder $binder = NULL) { if ($binder === NULL) { throw new Exception("A PHPExcel_Cell_IValueBinder is required for PHPExcel to function correctly."); } self::$_valueBinder = $binder; }