Re: Header/Details Considered Harmful

I think you've made a number of asssumptions that perhaps underly your 
concerns.  A few comments:

1) SOAP doesn't tell you who will do the XML parsing.  Many general 
purpose SOAP implementations will provide integrated parsing of both body 
and header entries as appropriate to assist the application or other 
middleware.

2) Header entries serve at least two related purpose.  First, even between 
just a pair of nodes, they are a very general extensibility mechanism. 
Note particularly the importance of "mustUnderstand".  Although simple in 
concept, it is a powerful building block for ensuring that two parties 
that may not have detailed knowledge of each others' software (this is 
>web< services after all) can indeed safely communicate.  Also:  in 
situations where a message is expected to traverse multiple nodes (e.g. 
stopping at a cache manager), header entries give you a way to address 
information to the intermediaries (e.g. don't cache this.)

Hope this helps.

------------------------------------------------------------------------
Noah Mendelsohn                                    Voice: 1-617-693-4036
Lotus Development Corp.                            Fax: 1-617-693-8676
One Rogers Street
Cambridge, MA 02142
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Received on Tuesday, 25 September 2001 13:53:21 UTC