finishOperation<T, R> method

FutureOr<R> finishOperation<T, R>(TransactionOperation op, T res, PreFinishDBOperation<T, R>? preFinish, { TransactionErrorResolver? errorResolver, })

Finishes the operation op with the result res of its transaction execution: applies preFinish (if any) and calls op.finish.

Called after the execution, not inside it: a preFinish can issue other operations in the same transaction (e.g. selecting the sub-entities), that are executed after it.

An error in preFinish is notified to the transaction, as an error in the execution (Transaction.notifyExecutionError, with errorResolver): the transaction is aborted, and the error rethrown. (Otherwise op would never be finished: the transaction neither committed nor aborted.)

Implementation

FutureOr<R> finishOperation<T, R>(
  TransactionOperation op,
  T res,
  PreFinishDBOperation<T, R>? preFinish, {
  TransactionErrorResolver? errorResolver,
}) {
  if (preFinish == null) {
    return op.finish<R>(res as R);
  }

  FutureOr<R> onError(Object e, StackTrace s) =>
      op.transaction.notifyExecutionError<R>(
        e,
        s,
        errorResolver: errorResolver,
        operation: op,
      );

  FutureOr<R> res2;
  try {
    res2 = preFinish(res);
  } catch (e, s) {
    return onError(e, s);
  }

  if (res2 is Future<R>) {
    return res2.then((r) => op.finish<R>(r), onError: onError);
  } else {
    return op.finish<R>(res2);
  }
}