Re: A matter of exception reporting style

From:

"Alf P. Steinbach" <alfps@start.no>

Newsgroups:

comp.lang.c++

Date:

Wed, 12 Aug 2009 18:29:16 +0200

Message-ID:

<h5ur0o$4na$1@news.eternal-september.org>

* Thomas J. Gritzan:

Alf P. Steinbach schrieb:

This particular mechanism is for a progromatic interface. Through a
published API a calling program has violated the contract. We are
returning the results. In this case the results will be formulated
into XML (not that it's terribly relevant).
<Result Status="Fail" ErrId="100">Reason for failure goes here</
Result>

The calling program can take corrective measures based on the
error code more easily than it can for text.

It can even more easily distinguish exception types. ;-)

How to get the type of exception into XML form?

That depends on the usage context. E.g. for XML as the serialization form of
remote procedure calls one would presumably need to conform to that. But the
basics is not more difficult than the base exception class providing a virtual
routine that supplies the class identifier.

For external programs,
C++ classes don't have any meaning.

The OP's original problem description used examples with 'throw ...', and the
new details supplied above still talk about a calling program.

There was no XML conversion.

A problem about exception class design is not a problem of XML conversion.

But instead of the (magic) numeric constant, the XML could contain an
error code string like ErrId="ErrCode1".

Yeah.

Cheers,

- Alf