In our PWG IPP phone conference today, the following proposal was brought up:
It is suggested that we create two new "shadow-operations" for
print-by-reference, one that looks like the Print-Job operation called
Print-URI, which is like Print-Job, but has an attribute containing a URI
instead of the print-data. Similarly one that looks like the Send-Document
but called Send-URI. It will then be crystal clear whether an
implementation supports print-by-reference, by examining whether one or
both of these operations are supported. The Validate operation will return
an attribute containing information about which operations are supported.
This proposal does not suggest adding additional attributes for security.
I support keeping print-by-reference in our solution as described above,
and meeting the requirements described by Roger deBry (which do not require
security).
Carl-Uno
At 02:47 PM 6/11/97 PDT, Stephen Holmstead wrote:
>Good summary of requirements. I think that when you narrow
>print-by-reference to this scoping, that is possible in a printer. I do
>think that there may still be some issues that we need to work through.
> For example, you will give the printer a URL. Somehow the printer has to
>be able to distinguish the content of this URL as pre-formatted IPP
>material versus generic web pages. This might be covered in the content
>description fields. Also, the printer needs to know if there is a
>pre-formatted type that it can handle (can the printer do postscript?).
> This might also be covered in the content description.
>--
>Stephen Holmstead
>Hewlett Packard Internet Solutions Operation
>stephen_holmstead@hp.com
>
>
>-----Original Message-----
>From: Roger K Debry [SMTP:rdebry@us.ibm.com]
>Sent: Wednesday, June 11, 1997 7:55 AM
>To: ipp@pwg.org
>Subject: IPP>MOD - Print by reference
>
>There has been quite a storm of email on the print by reference subject
>lately.
>Let me once again define what I believe to be a very significant customer
>requirement that print by reference can satisfy. In very carefully fencing
>this requirement it is important to say what it is not.
>
>It is NOT printing web pages. Much of the concern I have seen expressed in
>recent email, especially from HP, has to do with printing web pages. I
>agree
>that chasing links and dealing with the multitude of data types on the web
>is
>very complex and could potentially bloat a Printer implementation.
>
>It is NOT printing documents that require some security mechanism to
>access them. In particular it does not deal with the printing of documents
>where the right to print a copy of the document must be purchased. As
>Larry Masinter has suggested, the protocol may reserve some "space"
>to encode credentials for such transactions, but I do not want to
>complicate
>the model nor hold up approval of IPP as a standard trying to architect and
>get approval of these security mechanisms.
>
>There are at least two examples of what I think print by reference is for
>version one of IPP:
>
>First, consider the case of documents, such as Internet-Drafts, or those
>documents which we have on the PWG ftp site which are accessible
>by anonymous ftp, i.e. they are "publically accessible". Print by
>reference is a powerful tool for printing such documents. Documents
>are in some print-ready format, such as Postscript.
>
>Second, consider the case where an enterprise keeps a library of
>documents (standards, reports, procedures, etc) on a central
>repository that is accessible by anyone within the enterprise
>firewall. It would probably be on a private internal network. Print
>by reference is again a very powerful tool for printing such
>documents which are in some print-ready format.
>
>To summarize, this simple version of print-by-reference only
>requires that the documents to be fetched are already
>formatted for printing. The Printer does not deal with links,
>it does not format pages, it does not deal with dynamic web
>formats, etc.
>
>
>
>
>Roger K deBry
>Senior Techncial Staff Member
>Architecture and Technology
>IBM Printing Systems
>email: rdebry@us.ibm.com
>phone: 1-303-924-4080
>
>
>
Carl-Uno Manros
Principal Engineer - Advanced Printing Standards - Xerox Corporation
701 S. Aviation Blvd., El Segundo, CA, M/S: ESAE-231
Phone +1-310-333 8273, Fax +1-310-333 5514
Email: manros@cp10.es.xerox.com