PROPOSAL: Drop interface/operation/(input|output)/@headers

During the <message> elimination process, I proposed that it be
eliminated by introducing a single element that may go as the 
body of the message and zero or more "header" elements. The motivation
was that it was possible in WSDL 1.1 to have such header and body
parts and we didn't want to lose that functionality.

The main use of the "header" parts are to enable one to use WSDL
to describe middleware protocol type "applications" of WSDL. That
is, one can imagine protocols requiring certain headers to be 
present etc..

However, to fully describe such protocols the header stuff has to
be much much richer. If you look at the original context proposal
I made back in January this year, you'll see some of that richness,
but even that is not enough.

At the same time, complicating WSDL to the extent needed to make
it possible to fully describe a handful of middleware protocols
when compared to the millions of "regular" applications doesn't
seem like the right tradeoff. 

Thus, we now propose we drop the "headers" concept from input and
output messages. Messages will simply be a single XML element. 

I also propose a simple syntactic change to exploit this new 
simplified structure of messages. Rather than the current form:

    <input messageReference="xs:NCName" 
           body="xs:QName"? headers="list of xs:QName"?/>

I suggest we use:

    <input messageReference="xs:NCName" 

And similarly for <output>. The same syntactic approach can be
used to make <fault>s consistent with this approach. Rather the
current form:

    <infault messageRefernce="xs:NCName" details="xs:QName"/>

I suggest we use:

    <infault messageReference="xs:NCName" message="xs:QName"/>

And similarly for <outfault>.

Thus, this email proposes the following changes to status quo:
    - drop interface/operation/(input|output)/@headers
    - rename interface/operation/(input|output)/@body to
    - rename interface/operation/(infault|outfault)/@details to


Received on Monday, 20 October 2003 14:00:41 UTC