LC76d follow-up: difference between SOAP header blocks and SOAP modules

As I'm working on implementing the resolution of LC76d[1] and adding
wsoap:header to the SOAP binding, I realized that the SOAP header
block declaration is very similar to the SOAP module declaration.

I have actually used the text for wsoap:module for wsoap:header, which
made me realize that wsoap:module and the proposal for wsoap:header
that we adopted[2] — if you're following this link, note that we
decided to make it wsoap:header an element — work differently, and I
believe that they should not.

wsoap:module can be a child of:
- input
- output
- infault
- outfault

wsoap:header can be a child of:
- input
- output
- fault

However, SOAP modules and SOAP header blocks are very similar in terms
of their effect on the message: simplifying SOAP modules' role, they
add headers to the message. I don't think that they should be
expressed differently.

I would therefore like to propose that we align wsoap:header on
wsoap:module, i.e. have wsoap:header declarable on:
- input
- output
- infault
- outfault

We could also add the possibility to attach them on fault, but that
brings composition issues: the modules on an infault are the ones
declared for this infault plus the one for the referred fault.

In any case, having wsoap:module and wsoap:header work differently
seems awkward.

I have the beginning of some text for wsoap:header in the editors'
copy at [3]. However, it's currently a mix of all of those solutions,
as it allows wsoap:header on input, output, infault, outfault and
fault, without doing the fault/infault&outfault composition bit; I
have an ednote expressing the discrepancy, but that will give you an
idea of what the wsoap:header element looks like.

I'll finish implementing LC76d the right way once I hear some feedback
on this from the WG (I'd rather avoid doing the work twice).

Cheers,

Hugo

  1. http://www.w3.org/2002/ws/desc/4/lc-issues/#LC76d
  2. http://lists.w3.org/Archives/Public/www-ws-desc/2005Jan/att-0094/soap-header-blocks.html
  3. http://dev.w3.org/cvsweb/~checkout~/2002/ws/desc/wsdl20/wsdl20-adjuncts.html?rev=1.13&content-type=text/html;%20charset=utf-8#soap-headers-decl
-- 
Hugo Haas - W3C
mailto:hugo@w3.org - http://www.w3.org/People/Hugo/