Re: [SMW-devel] SMW 1.1: better querying, iCal, SPARQL, wiki registry

[Sergey C. <sem...@an...>]

On Wed, Apr 23, 2008 at 2:23 AM, Markus Krötzsch <ma...@ai...>
wrote:

> On Dienstag, 22. April 2008, Sergey Chernyshev wrote:
> > Markus,
> >
> > It's great news and I'll definitely be looking into RAP implementation
> for
> > integration with other tools we use!
> >
> > I have a couple of questions regarding the iCal and SMWRegistry though:
> >
> >    - Why do you use this strange encoding for the queries and other
> >    things in RSS/iCal URLs? it seems that you replace % with - which
> makes
> > it harder to interpret or create. I wonder what's the reasoning behind
> > this, why can't you just use regular url encoding?
>
> There are multiple reasons. The main reason is that we want to create
> internal
> links in MediaWiki to the query special page. Now if we would use %
> encoding,
> then MediaWiki would expand that in links to create symbols that are not
> allowed in links. You can try the query link:
>
> [[Special:Ask/%5B%5BCategory%3ATestpage%5D%5D]]
>
> (query "[[Category:Testpage]]")
>
> Another reason is that we use this as a common encoding in all contexts
> that
> occur in SMW. Now in RDF/OWL, URLs do alse occur as XML entities, and % is
> not allowed in such entities either.


I see. Maybe there should be some easy way to create RSS links - I use them
with FeedBurner (a fixed set of links, which does not allow dynamic feeds by
topic, for example) and they were pain in the neck to create, also I had to
hide all the complexity behind mode_rewrite rule (actually Apache freaked
out on this URLs too so I did it on my reverse proxy I use) because
FeedBurner failed to understand these long URLs.

It brings the question of savable queries - I wrote about this idea in
context of performance if you remember. In two words, it might make sense to
create special namespace for saved queries - where each page will define a
query and then that page serves as a name shortcut that can be used instead
of the full syntax. I use this approach in my Widgets extension:
http://www.mediawiki.org/wiki/Extension:Widgets - SMW can use it in various
places, e.g. as argument to {{#ask}} (instead of full query), as arguments
to RSS/iCal and other exporters and so on. This will relief developers from
URL issues (and also as I mentioned in last post, might be usable for
restricting querying functionality if combined with namespace permissions).

Let me know what you think - I'll be happy to discuss in more detail if
needed.

>    - SMW Registration is done by parsing Special:Version as I understand
> >    - why not to create an RDF export of the statistical data that your
> > service can consume in addition to the base data in Special:Version? I
> > understand that old version will not contain it, but there are lots of
> > other useful data that can be extracted and why not to use best Semantic
> > format to do that? The project is called "Semantic" MediaWiki, right? ;)
>
> We do :-) But that feature is only available since 1.1, hence we check
> Special:Version to be able to register also older SMWs. But all the
> additional information (e.g. page count) comes from
> Special:ExportRDF?stats.
> It would otherwise be very hard to parse this data from Special:Statistics
> in
> all languages.


Perfect! Now everyone can create a tool for visualizing SMW statistics.

BTW, how do I get
http://semantic-mediawiki.org/wiki/Special:SMWRegistrypage as RDF?
with seeAlso links to specific feeds for each wiki?


>
> >
> > I'll definitely try to upgrade TechPresentations, although first I'll
> need
> > to make sure that the rest of SMW extensions work fine.
>
> OK, great. I think the leap from 1.0 to 1.1 is not so large regarding
> internal
> stuff, so I am confident that no issues with extensions arise.
> TechPresentations of course cannot be registered anyway, since it blocks
> robots (btw, the SMW Registry robot should understand the ALLOW clause in
> robots.txt ;-)


I actually added it to robots.txt and will probably allow Special:ExportRDF
universally.


> I will soon (today) create another minor release since we spotted some
> problems with the 1.1 ICalendar export on various systems, which we fixed
> right away.


OK, I didn't upgrade to latest SMW yet, but I definitely plan it for near
future. Is there any way to roll-back SVN easily? I know you use WikiMedia's
wiki and they don't encourage tags or branches, but it might be very useful
to be able to roll-back somehow. Maybe it's worth posting a timestamp for
each release so it can be used for checkout?

            Sergey


-- 
Sergey Chernyshev
http://www.sergeychernyshev.com/


>
>
> Regards,
>
> Markus
>
>
> --
> Markus Krötzsch
> Institut AIFB, Universität Karlsruhe (TH), 76128 Karlsruhe
> phone +49 (0)721 608 7362          fax +49 (0)721 608 5998
> ma...@ai...          www  http://korrekt.org
>
>