[topicmapmail] Web Services

[Lars Marius Garshol]

* Jan Algermissen
| 
| The idea is that a topic map server can make certain portions of a
| topic map available, that suit common information needs. Some
| examples of such portions are
| 
|   - the 'index' of a topic map, meaning the list of topics with
|     their occurrences and the titles,abstracts,authors, etc. of the
|     occurrences
| 
|   - the 'reverse index', meaning the list of information resources
|     and the subjects they are occurrences of
| 
|   - the list of all classes
| 
|   - the list of all roles
| 
|   - the list of all assertion types
| 
|   - several forms of hierarchical structures, such as a
|     superclass-subclass tree or a spatial-containment tree
| 
|   - hitlists based on certain properties/situations of topics
| 
| many of these are present in the available topic map browsing
| softwares in one form or another.

Hmmm. This makes sense to me, but couldn't you express all of those
conditions as queries? It seems trivial to me to produce tolog queries
(and the same would probably apply to the other QLs) that express each
of these portions.
 
| The above conceptual portions can also be parameterized in order to
| retrieve only certain substes (e.g. index from A-C or some tree
| starting at X and going down n levels)

That requires a more powerful query language, but you're still within
the limits of what a QL can be expected to do.
 
| This way of accessing topic maps integrates nicely with Web
| architectire because the conceptual portions can be understood as
| resources and topic map servers can provide links to them to guide a
| user or agent (this is known as drill-down and navigation from a
| REST POV).

Yep, and I think that's a very sensible approach.
 
| Suppose a topic map server provides the xmltools map at
| 
| http://www.example.org/topicmaps/xmltools
| 
| then several portions could be accessed as:
| 
| http://www.example.org/topicmaps/xmltools/index
| http://www.example.org/topicmaps/xmltools/classes
| http://www.example.org/topicmaps/xmltools/roles

Right. So here you have effectively named queries, instead of exposing
the query interface directly over the web. We will probably create
something similar for our TM server product. That is, you can created
named methods that are implemented with queries, and which can be
rendered as XTM fragments or in some other way that you specify. 
 
| Of course there is more to all this, especially interoperability
| issues (e.g. the portions have to be commonly known/understood for
| non-human interactions) but I am still working the details out.

I like what you've described so far. It seems like there's even more
work going on in this area than I was aware of, which is very cool.
Probably there should be a standard for this eventually, but I don't
think the time has come for an ISO standard for this yet.

-- 
Lars Marius Garshol, Ontopian         <URL: http://www.ontopia.net >
GSM: +47 98 21 55 50                  <URL: http://www.garshol.priv.no >