Issue 392: draft proposals

I've taken a todo to provide a proposal for issue 392. Here is 
that proposal. Apologies for sending this after the f2f has started.

Jean-Jacques.

=================

Background
----------

The issue is about the Attachment Feature. The issue comes in two 
parts.

a) The issuer is asking whether intermediaries are allowed to 
add/remove secondary parts. More generally, the issuer is 
wondering whether there should be an equivalent to our well-known 
processing model, but one that would apply to secondary parts, 
not header blocks.

b) The commentator is also wondering whether some URI schemes are 
better adapted to insertion, deletion, and modification of 
secondary parts.

Analysis
--------

a)
Intermediaries already have access to the entire message, i.e. to 
all header blocks, even to the ones targetted at a role they do 
not assume. Similarily, I believe intermediaries must have access 
to all secondary parts, and I think Part 1 already allows this. I 
suggest documenting it in the AF document though.

In addition, intermediaries can insert/remove/change header 
blocks. Simple forwarding intermediaries are restricted to those 
blocks targetted at them. Active intermediaires can also 
change/remove those blocks not targetted at them. Similarly, I 
believe intermediaries must be able to insert/remove/change 
secondary parts. Potentially, this can create "dangling" 
references, as the commentator suggests, but this is akin and not 
worse than for header blocks.

b)
I think the second issue does not need to be addressed in the AF 
document, only in concrete feature specifications.


Proposal
--------

Add a new section on Itermediaries to the AF document.

<proposal>
Intermediary Considerations
===========================
Forwarding SOAP intermediaries MUST be able to access the entire 
SOAP message, including any secondary part. For any relayed SOAP 
header block, they MUST forward the secondary part(s) referenced 
by that block. They MAY relay secondary parts no longer 
referenced in the forwarded message. They MAY insert additional 
secondary parts. They MUST NOT change the content of the relayed 
secondary parts, unless that part is being reinserted together 
with the referencing header block.

Active SOAP intermediaries are subject to the same rules, except 
that they MAY change and/or remove secondary parts referenced by 
header blocks targetted at a role they do not assume. It is 
strongly recommended that such changes be described in a manner 
that allows such modifications to be detected by affected SOAP 
nodes further along the message path.
</proposal>

Received on Tuesday, 29 October 2002 13:08:37 UTC