W3C home > Mailing lists > Public > public-ws-addressing@w3.org > January 2005

RE: i009 - mustIgnore rule for multiple To, ReplyTo, etc.

From: <paul.downey@bt.com>
Date: Wed, 12 Jan 2005 16:38:02 -0000
Message-ID: <2B7789AAED12954AAD214AEAC13ACCEF2709DF05@i2km02-ukbr.domain1.systemhost.net>
To: <noah_mendelsohn@us.ibm.com>
Cc: <public-ws-addressing@w3.org>

Noah,

Thanks for your help, in particular the quotation from the SOAP 1.2
Rec S2.6[1]. I'm assuming that a similar processing model also applies 
to SOAP 1.1, though i couldn't find that explicitly stated in the note
or the WS-I Basic Profile. As i'm sure you are aware, we are chartered 
to provide bindings for both SOAP 1.1 and 1.2 and I believe it is 
desirable to have the same mustIgnore rule for multiple EPRs applied 
to both bindings.

> I'm not recommending one approach or another for ReplyTo and friends, 
> but just pointing out that the SOAP recommendation provides the option: 
> if you want to say in the specification for some SOAP header block: 
> "all occurrences of blocks with this QName must be processed in document 
> order", the SOAP Rec. says you can do that.  

That sounds good to me, assuming SOAP 1.1 has the same processing model.

> Now, whether most of the widely 
> deployed implementations of SOAP make it easy to achieve such 
> control is a different question. 

Given we're writing a specification I would like to think we can 
follow correctness here and specify a significance to the order for 
repeated headers in the wsa namespace. 

>From a brief look at a couple of SOAP APIs taken at random it seems 
that you can usually iterate through the SOAP headers in order, 
though some tools which provide an application binding, generating 
code for headers directly described in WSDL will have difficulties.
Then again such an approach at implementing wsa will encounter many 
other difficulties. Maybe this isn't such an issue in practice after 
all.

My remaining concern regards a use-case Don Box outlined at our Redmond
F2F in which other non-wsa components in a SOAP processing pipeline
may trigger off wsa headers, such as EPR parameters and properties. 
Such side-effects could be oblivious to our mustIgnore rule if they 
encountered a repeated item, but then they would have to consider
other items being repeated anyway - i don't see this as an issue.

So I'm happy to rewrite the Option#3 proposal more concretely to state 
'subsequent unexpected wsa:Address, wsa:wsa:To, wsa:ReplyTo, wsa:FaultTo 
items must be ignored", assuming there's no strong disagreement from 
the WG on this direction?

Paul

[1] http://www.w3.org/TR/soap12-part1/#procsoapmsgs
Received on Wednesday, 12 January 2005 16:37:11 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Tuesday, 2 June 2009 18:35:01 GMT