Re: Heirarchical error codes

[Rob Earhart <rob@xxxxxxxxxxxxxx>]

On Fri, 19 Mar 1999, Doug Royer wrote:
> I really think we need to be strictly define status codes. And only
> by revving CAP could they be added. Think interoperability.
>
> If I issue an ABORT and get back a 2.0.99 - what does that mean
> to the CUA?

  Even if v2 of CAP were to define that code, v1 clients wouldn't be able
to grok it; they'd just have to deal.

  I agree with you, though.  Actually, I think this is a great reason to
punt on hierarchical error codes entirely.

  The same orthogonality issues that come up in setting CAP version
numbers vs. capability lists come up in error/status codes.  It's more
extensible to send a not-necessarily-hierarchical stream of stuff that
clients can deal with or punt on, as needed.  One might envision some
client ten years down the road getting a response like

    S: a1 NO PERMISSION ("cal://foo.bar/some_object") TEMPFAIL
       MICROSOFT-ICON-NUMBER (16) "You don't have permission to do that
       right now."

(line breaks added for clarity; imagine that all as one line...).

  (ICON-NUMBER would be a really stupid extension, but that logic's never
stopped people before, and it makes for a nice example.)

  )Rob