[XML-SIG] Metadata in XBEL

Ross Burton r.burton@180sw.com
Wed, 28 Mar 2001 20:06:18 +0100


>  > I am involved in adding support for XBEL to Galeon, the GNOME Mozilla
>  > Gecko based browser.  Initial export is working, but there are several

>  > The specification for metadata is vague, <metadata> elements have a
>  > "owner" attribute which should be a URI. But what forms of metadata are
>  > valid? The DTD implies that there can be no children of metadata
>  > elements (the content is EMPTY).
>
>   Here's the problem:  What we want is to be able to say
> "ANY-and-we-really-mean-it", not ANY as defined in the DTD language.
> That definition tells us that ANY means anything *defined in the DTD*,
> which is pretty limited -- this is an inherited SGML wart.  I don't
> know how to express what we actually want in the DTD language; if
> anyone can tell me, I'd be glad to change the DTD for revision 1.1.
> If anyone can tell me how to do it in XSchema, I'd be happy to use
> that for the schema language instead of using the DTD language.

Ah.  I'm not a DTD expert so though that ANY meant literally anything.

>  > Currently Galeon-specific attributes are exported as follows:
>
> ...ugh!... Don't do that.

Okay.

>  > It does seem that the DTD is in error as requiring all metadata to be
in
>  > the owner attribute is rather limiting.  But what content is allowed as
>  > children of the metadata element? Just text? Or could the content of a
>  > metadata element be a free-form XML tree?  For example:
>  >
>  > <site ...>
>  >   <info>
>  >     <metadata owner="http://galeon.sourceforge.net">
>  >       <pixmap>/home/users/ross/pictures/slashdot.org</pixmap>
>  >       <toolbar>true</toolbar>
>  >     </metadata>
>  >   </info>
>  > </site>
>
>   This is *much* better!  It also matches the intent.

Right.  I'll change the code soon.  Maybe there should be an example of use
for the metadata elements in XBEL 1.1.

> Martin v. Loewis writes:
>  > That, of course, would mean that a version 1.1 of XBEL needs to be
>  > issued, so perhaps this is the time to think about other pending
>  > improvements.

>   I'm very happy with doing this.  In fact, I've made a couple of
> changes to the DTD and documentation based on comments from David
> Faure (from the Konqueror development group).
>   In particular, I've added the "icon" attribute to the <bookmark/>
> and <folder/> elements, and the "toolbar" attribute to the <folder/>
> element.  The later is intended to mark which folder should be used as
> the "Personal Toolbar" -- my tentative change allows it to have the
> values "yes" or "no", with "no" as the default.  This may need some
> reconsideration; I can envision having software that supports multiple
> toolbars, but I'm not sure of the best way to encode that
> information.  (It may even be appropriate to push that into
> application-specific metadata inside the <metadata/> element.)

I like those additions...  because they are the main reason Galeon has to
use metadata!  Galeon does allow multiple toolbars to be displayed (thinking
about it, just the one is a limitation really), but I think that a simple
"yes|no" with no as the default is good enough for that.  Pushing that into
metadata is not using the potential of the toolbar attribute.

>   Another idea I've thought about from time to time is of linking to
> other bookmark collections, so that a folder-like thing about be used
> to refer to another (possibly remote) XBEL document by URI, or to RSS
> or other documents that could be used to store bookmarks (possibly
> including Netscape-style HTML bookmarks).  I think this would be easy
> to support in XBEL, and it only takes software to make it useful. ;)

Sounds like the future plans for Gnobog (a GNOME bookmark organiser). At the
moment it just reads/wites Netscape/IE and can re-organise, but they are
planning on moving to a "filesystem" like architecture, where bookmarks are
stored seperately to the tree view. This way aliases are taken to the
logical extension and the entire system behaves just like an ext2 filesystem
with hard links everywhere.  Nodes in the tree will be allowed to point at a
bookmark entry, or another (possibly remote) set of folders.

I have no say whatsoever here, but I'm +1 for adding the toolbar and icon
attributes, clarifying the metadata elements and releasing 1.1 of the XBEL
spec. :-)

Regards, and thanks for the mails,
Ross Burton