IPP Mail Archive: Re: IPP> OPS - Proposal to go back to prec

Re: IPP> OPS - Proposal to go back to precluding 'out-of-band' values with values

From: Ron Bergman (rbergma@hitachi-hkis.com)
Date: Wed Mar 22 2000 - 21:10:20 EST

  • Next message: Hastings, Tom N: "IPP> ADM - IPP Slides for IETF47"

    Tom,

    Sounds good! I'll wait for your new draft.

        Ron

    "Hastings, Tom N" wrote:

    > Ron,
    >
    > We discussed your suggestion at the telecon today, and came up with the
    > name:
    >
    > 'admin-define' short for "it can be administratively defined"
    >
    > Ok?
    >
    > That change is the only remaining issue for the "Job and Printer Set
    > Operations" spec. So I'll update it and send it out. Its ready for IPP WG
    > Last Call.
    >
    > We also agreed to put a Move-Job operation in the next draft of the Admin
    > Set2 operations, rather than trying to get it into the "Job and Printer Set
    > Operations" spec.
    >
    > Thanks,
    > Tom
    >
    > -----Original Message-----
    > From: Ron Bergman [mailto:rbergma@hitachi-hkis.com]
    > Sent: Tuesday, March 21, 2000 18:05
    > To: Hastings, Tom N
    > Cc: ipp
    > Subject: Re: IPP> OPS - Proposal to go back to precluding 'out-of-band'
    > values withvalues
    >
    > Tom,
    >
    > I must have missed some of the emails, since I don't recall any serious
    > problems with extending parsers to allow new out-of-band values to
    > have a non-zero value. However, I don't see a strong need for the
    > value to be present as proposed for 'any-value'. So, I have no
    > objection to Yet Another Proposal (YAP). ;-)
    >
    > But why are you proposing the name change to 'custom'? This name
    > could have implied meanings which are not appropriate. I much
    > prefer keeping the name 'any-value'. An alternative name suggestion
    > is 'admin-type', short for "it can be administratively defined."
    >
    > Again, I cannot attend the conference call tomorrow, due to meeting
    > conflicts. Long time ago there were meeting minutes that summarized
    > the decisions made in the conference calls. Now, the only minutes
    > are deeply imbedded in new documents. Sure would be nice to see
    > minutes again. I am sure that there are many who are unable to
    > participate that would like to see the decisions made.
    >
    > Ron Bergman
    > Hitachi Koki Imaging Solutions
    >
    > "Hastings, Tom N" wrote:
    >
    > > After hearing the problems with existing parsers on extending IPP to allow
    > > new out-of-band values to have a non-zero value, it appears prudent to
    > > abandon such an extension. Please send comments to the mailing list. We
    > > will also discuss, tomorrow, Wednesday, 3/22, on the IPP telecon.
    > >
    > > Instead, lets replace the proposed 'any-value' out-of-band value which had
    > > an attribute syntax value with a simpler 'custom' out-of-band value which
    > > MUST have a zero length. The 'custom' out-of-band value (as with the
    > > 'any-value') is used in a Get-Printer-Supported-Values response for as one
    > > of the values of a requested "xxx-supported" attribute to indicate that
    > the
    > > System Administrator can set custom values using the
    > > "Set-Printer-Attributes" operation.
    > >
    > > Here is the suggested updates to the "Job and Printer Set Operations"
    > > document:
    > >
    > > 15.1 Changes to the March 8, 2000 version to make the March 21, 2000
    > > version
    > > The following changes have been made to the March 8, 2000 version to make
    > > the March 21, 2000 version as a result of the IPP WG telecons and mailing
    > > list discussion:
    > > 1. Changed the name of the 'any-value' out-of-band value to 'custom'.
    > > Removed the idea of encoding the attribute syntax that the 'custom'
    > > out-of-band value goes with. Instead, the spec for the attribute defines
    > > whether or not the 'custom' out-of-band value can be used.
    > > 2. Clarified that the 'custom' out-of-band value can be used in
    > > combination with other values of an "xxx-supported" Printer attribute.
    > > 3. Clarified that an implementation is not prevented from supporting
    > > some 'name' attribute values for "xxx-supported" out-of-the-box, if
    > desired.
    > > But these values would be returned in a Get-Printer-Supported-Values
    > > response, such like keywords are.
    > >
    > >
    > > 8.3 'custom' out-of-band attribute value
    > > The 'custom' out-of-band attribute value MAY be used as one of the values
    > of
    > > an "xxx-supported" Printer attribute to indicate that the client can
    > supply
    > > custom values in a request. The client MUST supply any such values in the
    > > particular attribute syntax explicitly defined for that attribute.
    > > See section 4.3 in this document for an example definition of the usage of
    > > the 'custom' out-of-band attribute value in any "xxx-supported" attribute
    > > returned in a Get-Printer-Supported-Values response.
    > >
    > > 8.3.1 Encoding of the 'custom' out-of-band attribute value
    > > The encoding of the 'custom' out-of-band attribute value is 0x17 (see
    > > [ipp-pro]). The value-length MUST be 0 and the value empty.
    > >
    > > 1.1 Get-Printer-Supported-Values Operation
    > > This OPTIONAL operation allows a client to request the values that the
    > > Printer allows in the Set-Printer-Attributes operation for "xxx-supported"
    > > attributes. If the Printer supports the Set-Printer-Attributes operation
    > > AND some of its "xxx-supported" Printer attributes are settable, then the
    > > Printer MUST also support this operation. This operation has identical
    > > request/response attributes to the Get-Printer-Attributes operation in
    > > IPP/1.1 [ipp-mod]. The operation also behaves identically to the
    > > Get-Printer-Attributes operation in IPP/1.1 [ipp-mod] with the following
    > > exceptions:
    > > 1. The Get-Printer-Supported-Values operation supports only
    > > "xxx-supported" attributes.
    > > 2. The Get-Printer-Attributes operation returns the current value of
    > > specified attributes while the Get-Printer-Supported-Values operation
    > > returns values that permit a client to determine what values of
    > > "xxx-supported" attributes the Printer supports in the
    > > Set-Printer-Attributes operation.
    > > 3. If an implementation does not support setting an attribute that is
    > > requested, it MUST NOT return that attribute in the Printer Attributes
    > Group
    > > of the Get-Printer-Supported-Values response. Furthermore, in such a
    > case,
    > > as in the Get-Printer-Attributes response, the Unsupported Attributes
    > Group
    > > of the response NEED NOT contain the "requested-attributes" operation
    > > attribute with any supplied values (attribute keywords) that were
    > requested
    > > by the client but are not supported or are not settable by the IPP
    > Printer.
    > > 4. The Get-Printer-Supported-Values operation does not return any
    > > values for any "xxx-supported" attributes that were configured by the
    > System
    > > Administrator using the Set-Printer-Attributes operation. Instead, if the
    > > Set-Printer-Attributes operation allows the System Administrator to
    > > customize the Printer's "xxx-supported" attribute by adding arbitrary
    > values
    > > of a specified attribute syntax, then the Get-Printer-Supported-Values
    > > operation MUST return the 'custom' out-of-band attribute value (see
    > section
    > > 8.3) as one of the values of the "xxx-supported" attribute. In other
    > words,
    > > the 'custom' out-of-band attribute value indicates that the Printer
    > > implementation supports clients setting arbitrary values for that
    > > "xxx-supported" attribute as long as the value is of the attribute syntax
    > > defined for that attribute.
    > > For example, if the Get-Printer-Supported-Values operation returns several
    > > keywords as the value of the "media-supported" attribute, then the
    > > Set-Printer-Attributes operation MUST accept any of these keywords as
    > values
    > > for the "media-supported" attribute. If the Get-Printer-Supported-Values
    > > operation returns a 'custom' out-of-band attribute value as one of the
    > > values of the "media-supported" attribute, then the Set-Printer-Attributes
    > > operation MUST accept any value whose attribute syntax is 'name' as values
    > > for the "media-supported" attribute.
    > > The Get-Printer-Supported-Values MAY return the 'custom' out-of-band
    > > attribute value for any IPP/1.1 or extension Job Template attribute if the
    > > implementation supports allowing the System Administrator to add values to
    > > the "xxx-supported" attribute using the Set-Printer-Attributes operation.
    > > In this case, the Printer MUST accept any value of the correct attribute
    > > syntax in a Set-Printer-Attributes operation that is setting that
    > attribute.
    > > For "xxx-supported" attributes that are defined with a choice of attribute
    > > syntaxes, such as 'keyword | name', it is the 'name' attribute syntax that
    > > the System Administrator can use to add new values, not the 'keyword'
    > > attribute syntax. For IPP/1.1 this requirement includes the following Job
    > > Template attributes:
    > > media-supported
    > > job-hold-until-supported
    > > job-sheets-supported
    > > For "xxx-supported" attributes that are defined to have only a single
    > > attribute syntax, the 'custom' out-of-band value indicates that the
    > Printer
    > > will accept any value of that attribute syntax in a Set-Printer-Attributes
    > > request for that "xxx-supported" attribute.
    > > If the 'custom' out-of-band attribute value is not one of the values of an
    > > "xxx-supported" attribute returned in a Get-Printer-Supported-Values
    > > response, then the Printer MUST NOT allow the Set-Printer-Attributes
    > > operation for that attribute to contain a value that is not one of the
    > > explicit values returned in a Get-Printer-Supported-Values response.
    > > See Appendix B for a full list of values returned by this operation.
    > >
    > > Send any comments to the mailing list.
    > > Thanks,
    > > Tom



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