At 10:18 AM 1/28/2003 -0800, Jeffrey Schlimmer wrote:
Mark,
thanks for pulling together these requirements. I would like to suggest
two more candidate requirements:
DR18. The specification must define a means to
format messages for down-level receivers that do not understand the
specification.
Maybe you can clarify this one Jeff...the way I read it, it sounds
impossible.
DR19. The
specification must enable efficient allocation of buffers by
receivers.
This one motivates some of the other requirements but it implies that the
sender
understand the receiver's memory allocation capabilities. On one
extreme the
requirement could amount to "give the content length of
attachments up front",
but at the other extreme it could require the interleaving of parts to
achieve a
serialization optimal for receiver processing.
As an example of the latter, the UPNP Printing folks worried about how
an
extremely long XHTML doc with many inline images could be a printed with
one
page buffer. While that may seem like an example far from the
one most
SOAP folks consider, once you get to pipelined processing of composed
SOAP services the differences begin to fade. These are cases you
want to
be able to handle and they are cases that non-XML systems deal
with.
Of course the serialization of XHTML is
well-defined. Serialization for arbitrary
receiver processing isn't. That makes this requirement difficult to
spell out
absent information on the receiver buffer capability. Consequently
one might
go for a requirement that asks the spec. to allow attachments to be
placed
in the stream physically near their first point of XML reference rather
than getting
into buffers. That would pick up the critical use case without
getting mired
in an open-ended problem.
DR20. The specification must allow messages to
be secured using the mechanisms defined in WS-Security.
--Jeff
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John J. Barton
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