IPP Mail Archive: Re: IPP> New CUPS 1.1 beta and set-job-att

IPP Mail Archive: Re: IPP> New CUPS 1.1 beta and set-job-att

Re: IPP> New CUPS 1.1 beta and set-job-attributes extension [why not use "job-sheets"?]

From: Michael Sweet (mike@easysw.com)
Date: Thu Mar 30 2000 - 00:17:14 EST

  • Next message: Michael Sweet: "Re: IPP> Document-format attribute.. [ipp-mod] clarification"

    "Hastings, Tom N" wrote:
    > ...
    > But in IPP/1.1 "media" isn't a 1setOf value, its a single value. So
    > we are confused by your response.

    Hmmmm.... For some reason we have implemented it as a 1setof all along
    in CUPS; maybe that was changed in some of the later 1.0 drafts, but
    we appear to have an even more serious problem: the media specifier is
    used to specify media size, type, and source (tray). However, this
    mechanism is not sufficient for specifying all three items (which is
    needed for many printers.) So basically, the current spec allows you
    to select only one of up to three values that must be specified to
    get correct output on some printers.

    Soooo, it looks like (for now) we're going to have to add "media"
    to a (getting longer) list of "extended" attribute syntaxes for

    FWIW, adding keywords or names that enumerate all possible
    combinations is simply not feasible - for a simple inkjet printer that
    supports a dozen media sizes and types you are looking at 100+
    "supported" values alone; a LJ4000 would up that number to a little
    over 500... The 1setof approach is the only one that makes sense
    (short of separating the attribute into media-type, media-source,
    and media-size, which makes a whole lot more sense)

    > ...
    > The simplest way to get document separator sheets would be to add a
    > keyword value to the "job-sheets" Job Template attribute that
    > indicates that document start sheets are wanted.

    But WHICH start sheets????? *Real* printing needs to support user-
    specified start, end, and insert sheets; while this is often out of
    the scope of a simple embedded implementation of IPP, any printing
    system interface (e.g. CUPS) *does* need to support it, and we
    shouldn't have to come up with a lot of non-standard extensions to
    do it!

    > There is also a PWG Document and Page Exceptions spec that allows a
    > client to submit a job and specify any Job Template attribute, such
    > as media for each document and/or for specific page ranges within
    > documents. Its available at:

    That is one possible implementation we're looking at for a future
    release, but at the moment we are going for basic functionality and
    1.1 compliance.

    Michael Sweet, Easy Software Products                  mike@easysw.com
    Printing Software for UNIX                       http://www.easysw.com

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