>Namespace names don't have to be dereferenceable:
>"http://www.ccil.org/~cowan/labor_yutz" is a perfectly good namespace =
name,
>even though there's nothing there (you'll get an error if you
>try to dereference it), because I assigned it and the namespace
>names beginning http://www.ccil.org/~cowan" belong to me.
>
Hmmm. Oh well, I guess the idea is still valid though in terms of DTDs =
and
Schemas in general. As they proliferate and go through versions, the ab=
ility to
assign some form of universal ID in such as way that applications can g=
et that
information from the parser would be a very useful way of dealing with =
some of
the potential confusion that could arise. It would be pretty simple, av=
oid any
need for centralization, etc...
It would be particularly easy to apply it to Schemas and XML files, bec=
ause it
would only require the agreeing on of a particular element type of attr=
ibute
type or extra blah=3D"duh" statement in the <?xml ?> line perhaps. Sinc=
e DTDs
don't have anything like that (do they?), I'm not sure how it would app=
lied to
them, though they are the files that would best benefit from such a thi=
ng.
>In particular, there is no reason why the referent of the namespace
>name should be a DTD.
Ok, so I'm confused. Maybe its just a V vs. NV thing or something. If I=
define
a namespace, don't I also define a set of tags that are valid within th=
at
namespace? I always assumed that the URL that the namespace mapped to w=
ould be
more than just a human readable unique identifier of some sort, and tha=
t it
would define the tags that legally belong to that namespace. I could se=
e how
this would not be required for a NV scheme I guess, since it doesn't ma=
tter.
But for validation purposes, not being able to know that "Burping" was =
not a
valid tag within the "PoliteSociety" namespace seems like its missing o=
ut on
something important for many applications.
I can appreciate that just the partitioning of the global namespace has=
merit
in and of itself, but if you look at the use of namespaces in programmi=
ng
languages (where I come from), its also important for them to have defi=
ned
content that can be validated against uses of them.
So am I missing something here? Do you mean its just not required, or t=
hat its
not been thought of at all?
----------------------------------------
Dean Roddey
Software Weenie
IBM Center for Java Technology - Silicon Valley
roddey@us.ibm.com
=