I have no problem using two separate attributes. But, I do think that color
and mono are appropriate here. I don't think min and max are as useful,
since you usually need more info to understand what set of printing options
give you min and max. Whereas, color and mono max speeds are commonly quoted
specs that have meaning to most people familiar with printers. And, like it
says in the current draft for pages-per-minute: "This attribute is
informative, NOT a service guarantee". User agent UI's and printer-fitting
applications will need to keep this fact in mind.
From: Pete St. Pierre [mailto:Pete.Stpierre at Eng.Sun.COM]
Sent: Thursday, November 05, 1998 2:35 PM
To: imcdonal at eso.mc.xerox.com; Erik.Guttman at Sun.COM
Cc: Angelo.Caruso at usa.xerox.com; Pete.StPierre at Eng.Sun.COM;
mikael.pahmp at axis.com; srvloc at srvloc.org; ipp at pwg.org
Subject: Re: IPP> Re: SLP Printer Service Template
I see the printer speed as best described by two separate attributes.
I think Jim and Erik have done an excellent job discussing the use of
specialized syntax within a singled value attribute to describe an
ordered list. This is an excellent solution for the uri related parameters.
In the specific case of the printer speed (mono vs. color), I'd
prefer to see two separate attributes. The use of a single, syntatically
bound attribute would make it impossible to locate a printer based on
a minimal speed. For example pages-per-minute-mono > 5.
Alternatively, does it make sense to make the speed less "color" dependent,
Using min-speed and max-speed instead?
>> The underlying IPP Printer object attributes 'printer-uri-supported'
>> and 'uri-security-supported' are (and MUST be) ordered lists.
>> If SLP purists insist that we can have no ordered lists as
>> values of a 'printer:' attribute, then we have a serious problem.
>>>> Separately, I think it would be FAR better to have a
>> 'pages-per-minute-mono' and
>> attributes in the 'printer:' template (perhaps with the
>> monochrome attribute being Mandatory and the color one
>> - Ira McDonald
>> High North Inc
>>There is no problem creating ordered lists as values for SLP.
>You can't use ',' to delimit them, though. You create a syntax
>for the lists to delimit the values which is distinct from SLP.
>For instance, you could use ';' as the delimiter.
>>In this example, pages-per-minute has two values from an SLP
>perspective "mono;10" and "color;1". You could parse this at
>the client side to be two values which have 'two fields' apiece.
>Parsing them out, you know that the printer has a speed of 10 for
>mono and 1 for color, etc. There is nothing in SLP or the template
>specs to stop you from adding semantics (ordering, etc.) to the
>string attribute values.
Pete St. Pierre
Advanced Development Group
Sun Microsystems, Inc.
Pete.Stpierre at Eng.Sun.COM