Ned Freed wrote:
But this then begs the more general question of whether there is to be an
attempt to "design" the XML usage space, and if there is, whether such an
attempt has any chance of succeeding.
If the answer to this is "no, we don't want to try and control the
development,
direction, and use of XML"
This is the position of W3C; certain building blocks are made available
(foundational blocks such as XML itself, XLink, XPointer, namespaces,
etc; useful common things like styleshets, SVG for images, RDF for
metadata which can be used or not as appropriate) but the way in which
people combine these building blocks is up to them, and the element
names that they use (when not using a building block that defines names
for them, like XHTML and SVG do) is entirely their own affair.
The resulting
mixtures and granularity will be whatever developers decide is appropriate.
Not just developers; increasingly, vertical markets. An XML namespace
for real-estate listings, for example. One for dental records. So forth.
And
in such a world I see little value in having an XML top level type. (Perhaps
no
real harm, but little value.)
The only value I would see is if the fallbacks and other behaviours of
the text/* tree were seen to be unavoidable and made the use of XML too
fragile there. XML element names and element content can use all sorts
of Unicode characters. Fallbacks to text/plain are not useful in
general, and fallbacks to 7-bit US-ASCII risk manglng the data. On the
other hand, as you said in another post:
About the only success story we have,
actually, are the image/audio/video top-level types, and while these have
worked out tolerably well, their actual value to end users isn't that great.
If it can be assumed that a program which falls back to text/plain has
already lost significant semantics anyway, and if it can be assumed that
such fallback is rarely of value and rarely happens, then the use of
text/xml is useful. If on the other hand the fallback is seen asa n
unavoidable problem, then an xml/* tree would, indeed, have value simply
by lifting such restrictions.
And in such a world a top-level XML type might
have some value, if only as a place to attach the ruleset.
Right, that was what I was trying to say.
(Delegation of XML
registration would also be something to consider.)
Perhaps, but who would own it? Oasis, perhaps? My sense is that W3C is
not interessted in being a central repository for all possible uses of
XML, many of which are not Web related in any way.
--
Chris
I basically don't have an opinion on which way this should go. My one
observation is that the IETF at least has typically opted to try and stay out
of areas like this in the past.
Ned