[XML-SIG] Proposed XBEL DTD

[Fred L. Drake]

Marc van Grootel writes:
 > > Marc, you argued for having an explicit metadata structure; do you
 > > want to respond to this?
 > 
 > Not quite, Fred. I proposed the meta tag approach. You came up with
 > metadata as a wrapper for multiple meta elements. I liked it. I

Marc,
  Sorry; I wasn't trying to saddle you with the specific structure,
just that there was an explicit structure.

 > believe that info like it is can extend the lifetime of the DTD, and
 > it can also be an escape-hatch for new bookmark apps. I guess the need
 > for some sort of metadata is apparent, it was there from the start
...
 >   <info>
 >     <meta name="xbel:owner">dma</>
 >     <meta name="a:foo">bar</>
...
 > We can claim the xbel namespace and put essential info stuff in it.

  We cannot "claim" namespaces; namespaces are declared using
processing instructions, as indicated in Greg's example.  Namespaces
don't need to be changed to be usable; they actually fit the need
fairly well, but I'm not convinced they're exactly what's needed by
themselves.
  I propose that <info> remains as a sequence of <metadata> elements,
each of which uses an attribute to indicate an application or scheme
of some sort.  <metadata> can be declared to hold #PCDATA or whatever, 
and then namespaces are used to describe the structure  of the
contents.  This would allow multiple applications to use the same DTD
as the source of their information (hence the same namespace), while
the distinction between applications is made clear.  (It's entirely
possible that multiple RDF schemes would be stored, so ownership of
various chunks may well need to be identified separately from the
namespace specifications.

 > I regret losing id from folder. Why is an alias to a folder stranger
 > then an alias to a bookmark. NS has the latter but not the first. MSIE
 > supports both. NS has a separator, MSIE doesn't know such a thing,

  I did not know this.  I'll add it back.  This does introduce the
possibility of circular data structures, so applications will need to
be careful about traversing aliases to folders.  That can be dealt
with in the documentation.  How does MSIE deal with aliases to
folders (including in the user interface)?
  I think the dominant requirement is that XBEL be sufficient for
storing all information currently stored in browser bookmarks for at
least the major browsers, and preferably minor players as well.


  -Fred

--
Fred L. Drake, Jr.	     <fdrake@acm.org>
Corporation for National Research Initiatives
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