[topicmapmail] Web Services

[Jan Algermissen]

Murray Altheim wrote:
> 
> Jan Algermissen wrote:
> > Murray Altheim wrote:
> >
> >>Jan Algermissen wrote:
> >>
> >>>Murray Altheim wrote:
> >>>[...]
> >>>
> >>>>Do people have to be aware of the list of IDs, or does
> >>>>the system just fail when either an expected ID isn't there, or
> >>>>when an inserted ID fails because it's already in use (or there is
> >>>>an error because of that ID).
> >>>
> >>>IMHO using element IDs for other referencing purposes than for reconstructing
> >>>the serialized graph are a bad choice anyway (as are PSIs that contain fragment
> >>>identifiers) due to the limitations they introduce when used over HTTP....
> >>
> >>Hmm. I'm confused about that last statement. If I publish a Topic
> >>Map as a source of PSIs, or an XHTML document that references an
> >>XTM document acting as that source, either way I have a single
> >>XTM document containing multiple <topic> elements, where each is
> >>potentially the Topic "behind" that the published PSI. I do this
> >>because the PSI is yes, just a string, but the Topic is perhaps
> >>firmly interwoven in a lattice of relations that might be important
> >>to my processor. So those fragment IDs are important to me. Being
> >>over HTTP or not doesn't seem to make a difference here. It's a
> >>reference on a local file system too.
> >
> > The problem with fragment identifiers is, that they are not part of the
> > message when you invoke a HTTP method on them. The consequence is that
> > no intermediary will see them and thus cannot add-in information it
> > might have about that URI.
> 
> I don't mean to be snide, but that's not my problem. :-)

Ok ;-)   

> 
> You are perhaps looking at this from the REST POV? 

I think the ability of intermediaries to enhance messages is a very
exciting (and for the Semantic Web an essential) concept.

> I'm looking at
> it from a server POV. The HTTP server certainly receives everything,

If you type http://example.org/foo#moo in your browser;s location bar,
the server will see

GET /foo HTTP/1.1
Host: example.org

#moo will not be part of the message. If your request runs through a
proxy that knows more about http://example.org/foo#moo it won't 
know that you are looking for http://example.org/foo#moo and thus
cannot add that knowledge.

If the URI was http://example.org/foo/moo in the first place 
everything would be fine.



> so the fragment identifiers do exactly what they should do upon being
> received, i.e., they point at a specific ID within the resource. All
> of this information is passed on to the application, right?

No, see above.
> 
> > Another problem is that creating flat namespaces (a single 'document' with
> > lots of significant fragments) will allways cause the whole document to
> > be transfered just to access the fragment (as said, the server will never
> > see the fragment, the user agent strips it off).
> 
> Again, I'm looking at this from a server POV. The server doesn't have
> to transfer everything if the ID is a part of a query.

What do you mean by 'query'?
> 
> > A more practical example is that you cannot, for example, submit a fragemnt
> > identifier-URI to a search engine for indexeing.  foo#1 and foo#2 are
> > exactly the same thing to them.
> 
> Same answer as above.
> 
> Perhaps we're talking about different things?

Maybe....


Jan


> 
> [I'll leave off discussion of encoding, since Lars Marius has
> answered that already.]
> 
> Murray
> 
> ......................................................................
> Murray Altheim                    http://kmi.open.ac.uk/people/murray/
> Knowledge Media Institute
> The Open University, Milton Keynes, Bucks, MK7 6AA, UK               .
> 
>    US envoy warns of Taleban return, BBC News
>    http://news.bbc.co.uk/1/hi/world/south_asia/3402813.stm
> 
>    When asked about concerns that the US call for "acceleration"
>    [on building up the Afghani army to fight the resurgent Taleban]
>    was linked to the timetable of American elections in November,
>    Mr Taylor said: "We all remember what happened in the United
>    States [on 11 September, 2001] and where those attacks came from."
> 
>    Saudi Arabia?  The attacks did not come from the Taleban, who
>    are only concerned with control of their own country.
> 
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-- 
Jan Algermissen                           http://www.topicmapping.com
Consultant & Programmer	                  http://www.gooseworks.org