There has been a lot of good comment on my earlier entry on outline
formats in XML.
I've been pretty busy the past week or so, but I'd better get my
thoughts down before they deliquesce.
Bob DuCharme pointed me at Micah's
includes mention of XOXO.
Henri Sivonen asked what I think of it.
Taking the name "outlining format" literally, it's actually just fine.
As Micah says:
Some people might feel warmer and fuzzier with elements named outline,
topic, item, and so on, or with elements in a freshly minted namespace,
but microformats can still claim the semantic high ground, even when
reusing XHTML. In the above, the parts of an outline are ordered lists
and list items, exactly as the XHTML element names say.
The problem is that what made me start looking into outlining formats
was the fact that I'd heard from others that these make such a great
format for personal information space organization, and XOXO is just
about useless in that regard.
Along that vector, I wonder what a pure outline format is useful for,
anyway? I can't remember having ever needed a stand-alone outline
document separate from what I'm outlining. If I'm writing a
presentation or a long article, I'd prefer to have the table of contents
or presentation outline section generated from the titles and structure
of the full work. Sure, XOXO might be suitable for such a generated
outline, but my exploration is really about hand editing.
In short I think XOXO is just fine for outlining, and yet I can't
imagine when I'd ever use it. As others have mentioned, and as I
suspected, the entire idea of outlining formats for general note-taking
is a big stretch. Danny Ayers mentioned in a
comment on the earlier format that for some attraction to OPML is a
matter of neat outlining UIs. I've always been conservative in adopting
UIs. I use emacs plus the command line for most of my coding, and after
trying out a half dozen blog posting tool for posting to Copia, I ended
up writing an e-mail-to-post gateway so that I can enter text
(markdown) into a UI I'm
already familiar with, Evolution's e-mail composition window.
As I said in the earlier entry, full-blown XHTML 2.0 makes more sense
than an outlining format for managing a personal information space, and
yet it seems too weak to me for this purpose. The weakness, as Danny
points out, is semantic. If everything in my personal information space
is just a para or an anchor or a list, I'll quickly get lost. As
followers of Copia know, my brain is a rat trap of wandering thoughts,
and I'm a poster child for the need for clearly expressed semantics.
As an RDF pioneer, I'm happy to use ideas from RDF, but I do not want to
type RDF/XML by hand. I've always argued, as Danny Ayers hinted, that
RDF should strive hard to by syntax agnostic, especially because RDF/XML
is awful syntax. I agree with him that
GRDDL is a good way to help
rescue XHTML microformats from their semantic soup, and I think this is
a better approach than trying to shovel all the metadata into the XHTML
header (Dan Brickley mentions this possibility,
but I wonder whether he tends to prefer it to GRDDL). GRDDL has a
natural draw for me since I've been working with and writing tools for
the XML+XSLT=RDF approach for about four years. But when I'm using
markup for markup (e.g. in a personal information space) I'd rather have
semantic transparency fitting comfortably within the markup, rather than
dangling off it as an afterthought. In a nutshell, I want to use the
better markup design of:
rather than the kludge of:
I think there's little excuse for why we don't have the best of both
worlds. People should be able to enjoy the relative semantic
cleanliness of RDF, but within the simplest constructs of markup,
without having to endure the added layer of abstraction of RDF. That
added layer of abstraction should only be for those aggregating models.
The fact that people would have to pay the "RDF tax" every time they
start to scribble in some markup explains why so many markup types
dislike RDF. I'm not sure I've found as clear a case for this point
than this discussion of extended uses for outlining formats.
Microformats are generally a semantic mess, from what I've seen of them.
They do best when they just borrow the semantics of existing formats, as
XOXO does, but I think they're not the solution to lightweight-syntax
+clean-semantics that the GRDDL pioneers hope. GRDDL has too much work
to do in bringing the rigor of RDF to microformats, and this work should
be part of the format itself, not something like GRDDL. I think the
missed opportunity here is that XML schema systems cling so stubbornly
to syntax-only-syntax. As I've been exploring in articles such as "Use
data dictionary links for XML and Web services
(I have a more in-depth look at this in the upcoming Thinking
XML article), one can make almost all the gains of RDF by putting the work into the XML schema, rather than heaping the abstraction directly into the XML format. And the schema is where such sophistication belongs.
But back to outlining and personal information spaces, I've tried the
personal Wiki approach, and it doesn't work for me. Again Danny nails
it: Wiki nodes and links are untyped. This is actually similar to the
problem that I have with XHTML, but Wikis are even more of a semantic
shambles. In XHTML there is at least a bit of an escape with
class="foo". The difficulty of navigating and managing Wikis
increases at a much greater rate than their information content, in my
experience. My Akara
project was in effect an attempt at a more semantically transparent Wiki, but since I wrote that paper I've had almost no time for Akara, unfortunately. I do plan to make it the showcase application for my vision of 4Suite 2.0, and in doing so I have an ally Luis Miguel Morillas, so there is still hope for Akara, perhaps even more so if I am able to build on Rhizome, which might help eliminate some wheel reinvention.