The following text suggests revisions to the current model
document to add the notion of createJob and SendDocument to the
IPP Model. Line numbers and section numbers are from the April
24th version 2.1 model document. The text which follows will
be slightly more readable if you use a mono-space font on your
mail.
Keith and I are proposing that we not use the byte range notion
discussed in last week's telecon but go back to the original
proposal. We do not believe that byte ranges add any value at
this point, they complicate the model, and are not consistent
with the way existing OS/2 and Windows drivers work. If at some
point we, or a specific vendor implementation, wants to add
checkpointing and recovery then this issue can be revisited and
properly designed to provide that function.
Finally, we did not use Bob Herriot's suggestion to add document
numbers. We see no immediate value in this proposal, it does not
fit the OS/2 and Windows models, and it assumes that we will use
a number to identify a document in the future and not a URL. It's
not clear that this is the right decision. So, in the spirit of
keeping things simple .............
Section 3, lines 690 - 696 becomes
Printer:
Create Job (Section ...)
Get Attributes (Section ...)
Get Jobs (Section ...)
Job Object:
Send Document (Section ...)
Get Attributes (Section ...)
Cancel Job (Section ...)
Section 4.1, lines 838 - 841 becomes
Operations which can be invoked on a Printer include:
Create Job (Section ...)
Get Attributes (Section ...)
Get Jobs (Section ...)
Section 4.2, lines 905 - 909 becomes
A Job object is used to model a print job. A job can contain one
or more documents. The information required to create a job
object is sent in a Create Job operation from the end user via a
client implementation to a Printer. The Printer may perform some
validation checks to verify that the job may indeed be processed.
For example, the Create Job operation may request that the
documents within the job be printed duplex (on both
Section 4.2, lines 933 - 935 becomes
The following operations can be invoked on Jobs:
Send Document (Section ...)
Cancel Job (Section ...)
Get Attributes (Section ...)
Section 4.3, lines 937 - 939 becomes
Documents consist of printable data and attributes which describe
the data to be printed. In this version of the protocol only
attributes defined in section 6.4.1 may be defined for individual
documents. Documents are sent in a Send Document operation.
Section 5.1, lines 1042 - 1045 becomes
For a Printer object:
Create Job (Section ...)
Get Attributes (Section ...)
Get Jobs (Section ...)
Section 5.1, lines 1047 - 1049 becomes
For a Job object:
Send Document (Section ...)
Cancel Job (Section ...)
Get Attributes (Section ...)
Section 5.2.1 lines 1067 - 1074 becomes
5.2.1 Create Job Operation
When an end user desires to submit a print job, the client send a
Create Job Request and receives a Create Job Response. The
information in a Create Job Request along with any default
information associated with the Printer is sufficient to create a
Job object. An instance of a Job object contains all of the
information needed by the Printer to print one or more documents
as a print job.
When a Printer receives a Create Job Request, it either accepts
or rejects the request. The Printer accepts the Create Job
Request and creates the a Job object if it is able to accept each
Issue: this section needs to be cleaned up to match the
conformance section and get rid of adornments
Section 5.2.1.1 lines 1101 - 1106 becomes
5.2.1.1 Create Job Request
The following abstract data types are part of the Print Request:
Job and Document A set of Job attributes as defined in
Attributes section 6.2. This section may be empty.
If so, Printer defaults are used.
Section 5.2.1.2 lines 1108 - 1109 becomes
5.2.1.2 Create Job Response
The following abstract data types are part of the Create Job
Response:
New section to be added:
x.x.x. Send Document Operation
Once a Job object has been created, a client uses the Send
Document operation to transport the documents to be printed and
add them to the named Job object. A document may be sent in a
single Send Document operation or split into pieces and sent with
multiple Send Document operations.
x.x.x.1 Send-Document Request
The client submits the request to a Job URL.
The following abstract data types are part of the Send-Document
request:
Content Length Number of data bytes in this Request
Document Part flag Indicates that this is the first,
middle, last, or only segment
of a document
End of job flag Used in the last request of a job
to signal end-of-job to the Printer
Document Attributes A set of Document attributes as
defined in section 6.4.
Document Contents <content-length> bytes of document
content in the format defined by
the Document-format atttribute.
Document content is optional and
not included when printing by reference.
x.x.x.2 Send-Document Response
The following abstract data types are part of the Send-Document
response:
Bytes Written Records the actual bytes accepted
by the Printer. This allows the client
to handle cases where the Printer failed
to accept the total amount of data in
the request for some reason.
Status status information, including error
status
Message optional status message
Section 6.4, replacement for the whole section
Note: I re-wrote this section to put all document attributes in
one place and clean up the definitions.
6.4.1 Document Data Attributes (Set by a Client/End User)
This group of attributes describes the document data for the job.
They are supplied in the Send-Document request.
6.4.1.1 document-name(name, Mandatory)
This attribute contains the name of the document used by the
client to initially identify the document. When a client prints
by reference, i.e. includes the document-URL attribute and no
document content, this attribute shall be absent. When a
document's contents are spread across multiple Send Document
operations, document-name is ignored by the Printer in all but
the first Send Document operation for that document.
6.4.1.2 document-format (type2 keyword)
This attribute defines the document format of this document. When
a client prints by reference, i.e. includes the document-URL
attribute and no document content, this attribute shall be
absent. When a document's contents are spread across multiple
Send Document operations, document-format is ignored by the
Printer in all but the first Send Document operation for that
document.
6.4.1.3 document-URL (url)
This attribute contains the URL of the document when the document
content is not included in the Send Document operation.
Document-number is the only other attribute allowed when a
document-URL attribute is present in a Send Document operation.
Examples
These examples may be included in the model document to halp
clarify the use of send document. However, this is open to
discussion. We believe that the model as now defined maps very
nicely to both the OS/2 and Windows driver model. Using the
proposal we saw from Babek at the San Jose PWG meeting, for
example, the Windows API calls would map as shown:
OpenPrinter - establish connection
StartDocPrinter - Create Job (printer url, job attributes)
WritePrinter - Send Document (job-url, part = first, length, data)
WritePrinter - Send Document (job-url, part = middle, length, data)
WritePrinter - Send Document (job-url, part = middle, length, data)
EndDocPrinter - Send Document (job-url, eoj, part = last, length, data)
ClosePrinter - close connection
The following example illustrates the use of Send Document in
more detail. In this example, a print job contains three
documents. The first requires multiple writes to send the job,
the second is a print by reference, the third can be sent in a
single write:
CreateJob (Printer URL, job-template attributes and values)
SendDocument (Job URL, document-part=first,
data-length=500,
document-name=DOC1
document-format=Postscript
<document content>)
SendDocument (Job URL, document-part=middle
data-length=500,
<document content>)
SendDocument (Job URL, document-part=middle,
data-length=500,
<document content>)
SendDocument (Job URL, document-part=last,
data-length=150,
<document content>)
SendDocument (Job URL, document-URL=<url>
document-name=DOC2)
SendDocument (Job URL, document-part=only,
End-of-Job,
document-name=DOC3,
document-format=PCL
<document content>)