Re: Media types

----- Original Message -----
From: "Mark Baker" <>
To: "Noah Mendelsohn" <>
Cc: "www-tag" <>; "xml-dist-app" <>
Sent: Tuesday, January 15, 2002 9:48 AM
Subject: Re: Media types

> > Ironically, a primary counterexample to the proposition that the root
> > element namespace determines the "type" of a document is SOAP itself.
If I
> > send a purchase order wrapped in a SOAP envelope, is it most useful to
> > consider this as "a SOAP document that by the way contains a purchase
> > order" or as "a purchase order that happens to be wrapped in a SOAP
> > envelope"?   I would argue that there are many cases in which the latter
> > represents a more useful view than the former, though both are valid in
> > principle.  Consider a message queuing system that receives different
> > of requests, including purchase orders, through a variety of protocols,
> > of which is SOAP.  In such a system, it may be as useful to type the
> > document as a purchase order rather than as a SOAP message.
> Neither a media type nor a namespace purports to be able to identify
> everything that a message means.  It simply acts as the "root meaning".
> If you buy TimBL's argument that the container specifies the meaning
> of containment (as I do), then the root container specifies the root
> meaning and that's the only place you can start in trying to construct
> the "whole meaning".
> To use your example, only because we know what the SOAP envelope means,
> do we know that the body should be processed as a purchase order (and
> that's assuming that there are no unknown mustUnderstand declarations).
> Another envelope format may define containment to mean something else.
> For example;
> <not xmlns="foo">
>   <banana xmlns="bar">
> </not>
> Is that a banana?
> I mostly agree with your points about SOAP though.  I just wanted to
> point out that they don't necessarily apply to other containers.
> MB
> --
> Mark Baker, Chief Science Officer, Planetfred, Inc.
> Ottawa, Ontario, CANADA.

Received on Wednesday, 16 January 2002 12:25:52 UTC