IPP Mail Archive: Re: IPP> PRO Section 9.7 vs. MOD section 4.3: need clarifica

IPP Mail Archive: Re: IPP> PRO Section 9.7 vs. MOD section 4.3: need clarifica

Re: IPP> PRO Section 9.7 vs. MOD section 4.3: need clarifica

Carl Kugler (kugler@us.ibm.com)
Tue, 7 Apr 1998 17:32:01 -0400

Thanks for the lucid explanation of Job Object attributes!

I think I've got it now. Let me run this past you to make sure.
attributes-charset and attributes-natural-language only appear as Job O=
Attributes (or, more specifically, Job Description Attributes) in respo=
nses to
Get-Job-Attributes or Get-Jobs requests. They MUST be sent if the clie=
requests them in requested-attributes, because they are MANDATORY Job
Description Attributes and thus MUST be supported. Furthermore,
attributes-natural-language (but not necessarily attributes-charset) M=
UST be
sent in the Job Object attribute group returned for any job that was su=
with a natural language which differs from that specified in the
attributes-natural-language Operation Attribute of the response. Right=


ipp-owner@pwg.org on 04/07/98 02:01:15 PM
Please respond to ipp-owner@pwg.org
To: hastings@cp10.es.xerox.com, Carl Kugler/Boulder/IBM@ibmus
cc: robert.herriot@Eng.Sun.COM, ipp@pwg.org
Subject: Re: IPP> PRO Section 9.7 vs. MOD section 4.3: need clarifica

>But my question is specific to Job Description Attributes.* Aren't tho=
>distinct from Operation attributes?

Job Description attributes are one of two categories of Job (Object)
Attributes. The other category is job template attributes.

Operation attributes (i.e. those attributes in the operation attributes=

group) are attributes that are passed as part of a request or response.=
of these attributes in a request set the values of job description
attributes which have the same name but they never set job template
attributes. Attributes in the job attributes group of a request cause j=
template attributes in the job object to be set, but not job descriptio=

Now you're probably wondering why some job attributes are job template
attributes and others are job description attributes. Some attributes h=
gone back and forth between these two categrories several times. The
original idea was that job template attributes are those collection of =
attributes which a client, even the end user, is allowed to modify. Th=
attributes typically have a list of supported values for the client to
choose from and a default value if the client doesn't choose a value. =
job description attributes are either set by the printer with no input =
the client, e.g. job-id, or they are characteristics of a job that a us=
has no choice about, e.g. job-k-octets and document-format. These latte=
attributes have supported values and sometimes a default, but a client
doesn't have a choice. The number of octets and the document-format are=

inherent qualities of the document.

>Section 4.3 says that attributes-charset and attributes-natural-langua=
>Job Description Attributes MUST be supported by printer objects.
>(M*) indicates MANDATORY attributes that an IPP object MUST support, b=
>that a client may omit in a request or an IPP object may omit in a res=
>Isn't that the case for these particular Job Description Attributes?* =
Or is
>there some subtle difference between the "job-description" attribute g=
>described in section 4.3 and the "Group 3: Job Object Attributes"
described in

I hope the above explanation clears up the difference between job objec=
attributes and job description attributes for requests. For reponses, =
job attributes group can contain any job attribute, including job
description and job template attributes.