Fwd: XML Protocol LC issue 470 resolution

In case this didn't get picked up on the comments list --

This is another path for XOP-based media types that we didn't consider. 
I haven't looked into it deeply yet, but I think it bears 
consideration; it would help smooth the way for other formats that want 
to use XOP.

One thing to look into -- will other packaging mechanisms accommodate 
this?

Begin forwarded message:

> From: Graham Klyne <[email protected]>
> Date: June 30, 2004 12:25:47 PM PDT
> To: Mark Nottingham <[email protected]>
> Cc: [email protected]
> Subject: Re: XML Protocol LC issue 470 resolution
>
> At 16:07 29/06/04 -0700, Mark Nottingham wrote:
>> Graham,
>>
>> The XML Protocol Working Group has resolved issue 470 [1], regarding 
>> XOP's use of media types.
>>
>> Regarding section 1.2: this was indeed a typo, and we will have it 
>> corrected in the next draft.
> ...
>> 1. http://www.w3.org/2000/xp/Group/xmlp-lc-issues#x470
>
> OK.
>
>> Regarding section 5: we did consider such a solution, but it had the 
>> drawback that the original media type
>> would not be visible at the outer level using Multipart MIME.
>>
>> In other words, the multipart/related media type only allows a 
>> parameter to identify the media type of the root part; any parameters 
>> of the root part's media type must be discovered by examining the 
>> root part itself.
>>
>> Given this, we decided that the current design of XOP regarding media 
>> types, while not optimal, was the best we could do within the 
>> limitations of the MIME system.
>
> Hmmm...
>
> Multipart/related also has an optional Start-Info parameter:
>
> [[
> 3.3.  The Start-Info Parameter
>
>    Additional information can be provided to an application by the
>    start-info parameter.  It contains either a string or points, via a
>    content-ID, to another MIME entity in the message.  A typical use
>    might be to provide additional command line parameters or a MIME
>    entity giving auxiliary information for processing the compound
>    object.
>
>    Applications that use Multipart/Related must specify the
>    interpretation of start-info.  User Agents shall provide the
>    parameter's value to the processing application.  Processes can
>    distinguish a start-info reference from a token or quoted-string by
>    examining the first non-white-space character, "<" indicates a
>    reference.
> ]]
> -- http://www.ietf.org/rfc/rfc2387.txt
>
> Which it seems to me might be used to convey the desired information 
> at the top level.  I suggest appropriate use of this parameter might 
> be made mandatory when in conjunction with the a root type of (say) 
> application/xop+xml, e.g.
>
> Content-type: multipart/related
>   ;type=application/xop+xml
>   ;start=...
>   ;start-info="original-content-type=application/soap+xml"
>
> ...
>
> #g

--
Mark Nottingham   Principal Technologist
Office of the CTO   BEA Systems