W3C home > Mailing lists > Public > www-rdf-interest@w3.org > October 2000

RE: aboutEachPrefix: possible alternative

From: David Wagner <dwagner@sa.kevric.com>
Date: Mon, 2 Oct 2000 16:29:33 -0500
To: "'RDF Interest \(E-mail\)'" <www-rdf-interest@w3.org>
Message-ID: <C9B23C6D1899D21188F600C00D009F86254D28@KEVRICSA1>
Dan Brickley wrote:
>I need to re-read your proposal more carefully; my initial reaction
>is: useful goal, not sure about the machinery for getting there.

>To flesh this out a little:

>In the 'aboutEachPrefix' / PICS tradition, I might want to say that
>every resource whose URI matches http://playboy.com/.*jpg is of
rdf:type
>foo:PotentiallyRudePicuture.
>
>In other contexts, I might want to create an RDF class
>bar:FriendRelativeOrCoWorker and populate it using an RDF query, so
that
>various people (or their mailbox URIs or whatever) are represented as
>being of that rdf:type.
>
>In both contexts, I might want to make generic descriptive claims
about
>the members of these classes. So mechanisms such as the one you
sketch
>might fit into a bigger picture involving other (less URI/regex
>centric) ways of picking out collections of Web resources.

Indeed, and I think even the example you gave is not best expressed as
a URI pattern.  What I think you mean is every resource whose URI
starts with "http://playboy.com/", and whose MIME type starts with
"image" or "video".  (Best practice URI is not to use the filename
extension, which also may be one of many available for images.)
Additionally, you may mean to include http://server2.playboy.com/ and
any other servers in the same domain, now or in the future.  But
unfortunately, the aboutEachPrefix construct does not address these
cases without explicilty listing every host.  I also wonder if it
would even have difficulty with port numbers in the URI.  (I am
considering this especially for what it implies to a web of trust.  If
the Consumer Reports rates the services provided by http://example.com
as questionable, I would hope this shady business could not simply
change the server name or port number to avoid these ratings!)

I have considered two possibilities for what I am implementing.
Following the aboutEachPrefix model I have considered adding many
attributes including these.

 aboutEachRegEx
 aboutEachDomain
 aboutEachHost
 aboutEachMIMEtype

This list may get mighty long.  Another more promising possibility is
matching on URI syntactic components after tokenizing along the lines
of of http://www.isi.edu/in-notes/rfc2396.txt, 3. URI Syntactic
Components.

I agree there is a much bigger picture and there are many people still
hashing this out (the developers of Apache's Cocoon project just
developed their own URI matching syntax) even as they implement it.

-David
Received on Monday, 2 October 2000 17:39:18 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 7 December 2009 10:51:44 GMT