- From: <Noah_Mendelsohn@lotus.com>
- Date: Wed, 31 Oct 2001 16:37:12 -0500
- To: "Doug Davis" <dug@us.ibm.com>
- Cc: henrikn@microsoft.com, hugo@w3.org, jacek@systinet.com, xml-dist-app@w3.org
Dug Davis writes: >>then that to me would very loudly >> imply boxcarring in 2+ body block case. Not necessarily. What if part one of the body tells you what to do (get stock quote) and part two tells you how to do it better (hints on where to look for the data). We don't say anything about what the semantics of each body (or header) entry is, or what they might mean together. If _you_ want to try to use it for boxcarring, that's your business. I believe I have suggested before that we should say something like: "For a node to understand a header or body entry, it must understand the entry'sforspecification not just in isolation, but in conjunction with the specification for all other header and body entries targeted to that node. The specifications for such header and body entries MUST describe or provide sufficient information to describe their proper use in combination; in cases where the specifications do not provide such information, the node MUST NOT "understand" any such entries." Therefore, if there was more than one body entry, or a body entry in combination with one or more header entries for the anonymous actor, the above rule will determine whether the endpoint node can indeed process the message. If the specifications call for box carring, that's your business. If, as above, they explain how the second entry will help you get stock quotes more effectively, that's fine too. In practice, I expect that suites of features will be developed for use together. So, for example, we can decide whether a digital signature is to be applied before or after a message is encrypted, presuming that both functions are requested in separate header entries. The specification for each feature would refer to the other. In other cases, very broad approaches could apply. So, if I develope the specification for a header entry with semantics "caching allowed", I might say "this header entry provides declaritive information, and therefore can be "understood" and acted upon in conjunction with any other header entry that does not specifically disallow caching functions." Or some such. Underneath this all is indeed a deeper question that Jacek brought up on today's call. Everyone seems to believe that the body is actually different in practice, that it somehow conveys "the main point" of the message. As he says, most existing implementations provide special handling for it. If we really mean it to be special, then we should give some guidance as to how it is special, and how it is to be used. As I read the specification today, it implies that you might just as well do all your working header entries (except that for mysterious reasons the body happens to be required). ------------------------------------------------------------------------ Noah Mendelsohn Voice: 1-617-693-4036 Lotus Development Corp. Fax: 1-617-693-8676 One Rogers Street Cambridge, MA 02142 ------------------------------------------------------------------------
Received on Wednesday, 31 October 2001 16:48:51 UTC