Semantic Model Mail Archive: RE: SM> Keyword Extension ISSUE

Semantic Model Mail Archive: RE: SM> Keyword Extension ISSUE

RE: SM> Keyword Extension ISSUE 1

From: Zehler, Peter (
Date: Fri Sep 27 2002 - 10:14:45 EDT

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    A question on C), I am not sure what you mean by well formed. I assume it
    is not well formed in the XML sense. My guess is that it is well formed in
    the PWG sense. That only means that the keyword values used are well-known
    values. It does not mean that the values are supported by the Printer
    instance. Is there any requirement for the schema to restrict the
    well-known values to the subset supported by a Printer?

    I somewhat disagree with D). I think it is more important to facilitate the
    operational use of the PWG schema in product environments. The well-known
    values in question are not meant for end-user consumption. Facilitating the
    developers can be accomplished through a transformed schema that takes
    appinfo and makes them enumerations. The client implementation can localize
    or present, in an application specific manner, keywords from appinfo or

    We have elements that can be vendor or site extended. Whatever we end up
    with I want to insure that Clients are able to discover, via GetAttribute
    action or a schema, and send those extended values. The Printer must allow
    the application to determine if the attribute/value is supported.

    As for B), I misspoke. What I intended to say is "Enable print client
    developers to ascertain the supported keywords for an element of a Printer
    at runtime" I believe the PWG Semantic Model defines the basic objects,
    their attributes, the well-known values for specific attributes and the high
    level description of the actions on the objects. We have seen in real world
    examples that vendors and site specific extensions and restrictions exist
    and are critical to many customer solutions. Static definitions may be
    applicable in certain solutions but the majority of solutions require the
    ability to determine what attributes and values are supported. Capability
    discovery is somewhat related but goes well beyond what attributes/vales are
    implemented by a Printer. Our goal should be to make the individual
    semantic elements useful for a capabilities solution.


                                    Peter Zehler
                                    Xerox Architecture Center
                                    Voice: (585) 265-8755
                                    FAX: (585) 265-8871
                                    US Mail: Peter Zehler
                                                    Xerox Corp.
                                                    800 Phillips Rd.
                                                    M/S 128-30E
                                                    Webster NY, 14580-9701

    -----Original Message-----
    From: TAYLOR,BOB (HP-Vancouver,ex1) []
    Sent: Thursday, September 26, 2002 4:42 PM
    To: PWG Semantic Model WG (E-mail)
    Subject: RE: SM> Keyword Extension ISSUE 1

    I'd add:

    C) Allow system entities to use standard XML tools and the PWG (and
    potentially other) schemas to determine that a request is well formed
    D) Facilitate development around the PWG semantic model by creating
    schema structures that expose both objects and values through commonly used
    development tools

    As for B), I'd say the semantic model certainly needs to enable capabilities
    to be ascertained, but I'm not honestly sure whether it's in scope for the
    SM project to "completely" solve this. It may be sufficient here just to
    declare the objects & values in such a way that they can be readily used by
    capabilities schemes, and that the "full" capabilities problem will be
    solved in forums like PSI & UPDF.


    > -----Original Message-----
    > From: Zehler, Peter []
    > Sent: Thursday, September 26, 2002 5:50 AM
    > To: PWG Semantic Model WG (E-mail)
    > Subject: SM> Keyword Extension ISSUE 1
    > All,
    > As stated in the previous mail note "CORRECTED Keyword
    > Extension Mechanism
    > for schema" sent earlier, I would like to resolve ISSUE 1.
    > ISSUE 1: What requirements do we have to help us close on a solution?
    > It seems to me that the primary objectives are to
    > A) Insure that the schema for the print model is easily
    > extended. For both vendors and sites. The extensions should
    > be allowed at
    > both the object and semantic element value levels.
    > B) Enable print client developers to ascertain the
    > capabilities
    > of a print device at runtime.
    > I think I heard a requirement that a client be able to
    > determine that a
    > request is well formed, in the PWG schema sense, using XML
    > tools and the PWG
    > schema. Am I hearing that requirement correctly?
    > What do you think the requirements are for selecting a
    > solution for schema
    > extensibility?
    > Pete
    > Peter Zehler
    > XEROX
    > Xerox Architecture Center
    > Email:
    > Voice: (585) 265-8755
    > FAX: (585) 265-8871
    > US Mail: Peter Zehler
    > Xerox Corp.
    > 800 Phillips Rd.
    > M/S 128-30E
    > Webster NY, 14580-9701

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