There are a couple of items that I was hoping somebody could clarify for
me. The first is an apparent conflict between the protocol and model
documents. Here is a synopsis:
On page 133 of the model document, in section 15.3.3.1 is the
paragraph:
"If an IPP object receives a request with (1) required
attribute groups missing, or
(2) the attributes groups are out of order, or (3) the groups
are repeated, the IPP
object REJECTS the request and RETURNS the
'client-error-bad-request' status code."
However, the protocol document states on page 5 that:
A receiver of a request SHALL be able to process as equivalent
empty attribute
groups:
a) an xxx-attributes-tag with an empty
xxx-attribute-sequence,
b) an expected but missing xxx-attributes-tag.
Perhaps I am not reading the documents correctly, but case "b" in the
protocol rule appears to conflict with case "1" in the model rule.
Please let me know if and how I am interpreting this incorrectly.
Also, on page 130 of the model document note 3 states:
"The Unsupported Attributes Group is present only if the client
included some
Operation and/or Job Template attributes that the printer
doesn't support whether
a success or an error return."
It would seem that the "error return" case would contain either 0 or a
subset of all Unsupported Attributes. Either an error case can occur
before any or all Unsupported Attributes were found. The question is, is
there any significance to the Unsupported Attributes list that is
returned given that the list could be incomplete? Should the only
attribute in the list be the offending attribute, if found? If an
unrecoverable error occurred then there is no way to complete the list.
Perhaps, if my thinking is correct, note 3 could exclude Unsupported
Attributes in the error case.
Again please let me know if my understanding of the document is
correct. Any help would be appreciated.
Thanks,
Brendan Galten
Brendan Galten
RBI Software Systems
510-204-9980
bgalten at rbi.com