I agree with you that 'unknown' could be used with any "xxx-supported"
attribute. Also we could define 'any' to be used with any "xxx-supported"
attribute. (I see from a message from you that I just read you wanted 'any'
to be available for any "xxx-supported" attribute).
I think that the IPP WG felt that there was enough of a difference between
'unknown' and 'any' to create a new OOB value.
'unknown' means that the Printer doesn't know what the value is. However,
the standard isn't clear how job validation works against a value of
'unknown' on a Job Creation operation.
'no-value' means the administrator hasn't configured it. However, the
standard isn't clear how job validation works against a value of 'no-value'
on a Job Creation operation.
'any' means that any value will match and the presumably, either the
implementation or the administrator has knowingly configured the Printer for
'any'. And such an extension would clearly specify that any value supplied
by a client would be acceptable. The only down side is that existing
clients querying the Printer's "xxx-supported" will not know what this new
tag value means and will not know how to display it to a user.
Tom
-----Original Message-----
From: kugler at us.ibm.com [mailto:kugler at us.ibm.com]
Sent: Tuesday, July 18, 2000 14:46
To: Hastings, Tom N
Cc: Michael Sweet; Hastings, Tom N; ipp at pwg.org
Subject: RE: IPP> OPS - Redirect-Job (a ka Move-Job) included in Job and
P rinter Admin (Set2) spec
I claim that IPP/1.1 already allows a Printer to return the OOB value
'unknown' for any supported attribute. So, it would automatically be
allowed for "redirection-printers-supported". The semantics of 'unknown'
might actually make sense here. The Printer is saying that it doesn't know
which Printers it can redirect to; it can only try them on a case-by-case
basis. So a client, on seeing 'unknown', might decide to go ahead and try
redirecting to some Printer it has in mind. Worst comes to worst, the
request will be rejected.
Or we could use 'any'.
The heart of the issue is in the containment matching rules. The spec says
things like "if the client-supplied xxx is not contained in the Printer's
xxx-supported, the Printer MUST reject the request". Presumably, if
xxx-supported is 'any', it matches any client-supplied xxx. If
xxx-supported is 'unknown', that might be interpreted as saying that the
Printer will decide whether or not to reject a supplied xxx only when it
has seen the request.
-Carl
"Hastings, Tom N" <hastings at cp10.es.xerox.com> on 07/18/2000 01:50:01 PM
To: Carl Kugler/Boulder/IBM at IBMUS, Michael Sweet <mike at easysw.com>
cc: "Hastings, Tom N" <hastings at cp10.es.xerox.com>, ipp at pwg.org
Subject: RE: IPP> OPS - Redirect-Job (a ka Move-Job) included in Job and P
rinter Admin (Set2) spec
Carl,
We considered your request to either add 'any' as a new out-of-band value,
or to extend the existing 'unknown' out-of-band (OOB) value to mean any.
The group agreed to add 'any', since it requires an updated client to not
be
confused querying the Printer before sending the job, if the client queries
the Printer as to what it supports before sending the job. (On the other
hand, an existing client that is simply querying the Printer will become
confused by a new OOB value).
You only requested it for "document-format-supported" (for use by a Printer
object that represents a Document Repository, instead of an output device).
However, in this example you are suggesting that the OOB value could also
be
used as the value of the "redirection-printers-supported" (1setOf uri)
Printer attribute, correct?
Tom
-----Original Message-----
From: kugler at us.ibm.com [mailto:kugler at us.ibm.com]
Sent: Tuesday, July 18, 2000 09:32
To: Michael Sweet
Cc: Hastings, Tom N; ipp at pwg.org
Subject: Re: IPP> OPS - Redirect-Job (a ka Move-Job) included in Job and
Printer Admin (Set2) spec
The Printer could return the OOB 'unknown' value in
"redirection-printers-supported" and let the client attempt a Redirect-Job
to any printer-uri. The operation will either succeed or return an error
code.
-Carl
Michael Sweet <mike at easysw.com> on 07/17/2000 07:06:14 PM
To: Carl Kugler/Boulder/IBM at IBMUS
cc: "Hastings, Tom N" <hastings at cp10.es.xerox.com>, ipp at pwg.org
Subject: Re: IPP> OPS - Redirect-Job (a ka Move-Job) included in Job and
Printer Admin (Set2) spec
kugler at us.ibm.com wrote:
> ...
> It's an implementation detail whether or not the
> "redirection-printers-supported" are on the same server. You only
> need to specify the protocol. If an implementation can meet the
> spec, it doesn't matter how it does it. You don't need to specify
> ...
But this brings up the issue of how we specify "all" servers,
i.e. we don't want to enumerate every printer-uri on the planet,
do we? :)
--
______________________________________________________________________
Michael Sweet, Easy Software Products mike at easysw.com
Printing Software for UNIX http://www.easysw.com