transaction method

@override Future<ChalonaResponse> transaction(TransactionFn fn)

Implementation

@override
Future<ChalonaResponse> transaction(TransactionFn fn) async {
  var connection = await _connect();
  dynamic r;

  r = await connection.runTx((tr) async {
    return await fn(PsqlTransaction(tr));
  });

  await connection.close();

  if (r is ChalonaResponse) {
    return r;
  }
  // no hay datos
  if (r.isEmpty) {
    return ChalonaResponse(
        source: {'ok': true, 'msg': 'no-results', 'data': {}});
  }
  // es un mapa de datos, con ok, msg y data
  if (r.length == 1 && r.first.containsKey('ok')) {
    return ChalonaResponse(source: r.first);
  }
  // es una lista de datos
  return ChalonaResponse(source: {
    'ok': true,
    'msg': '',
    'data': {'result': r}
  });
}