Nathan wrote:
Hi Again :)
Last question(s) related to fragments.. if I have:
http://example.org/something
http://example.org/something#a
Those are two unique URIs and thus two unique resources (?)
My world view (i.e. I don't do Resource and Information Resource lingo):
Careless and dangerous, but accurate.
1. http://example.org/something -- a resource URI
2. http://example.org/something#a -- a resource URI
Less confusing, assuming you are have a # terminated URI pattern in play:
1. http://example.org/something -- a resource URL
2. http://example.org/something#a -- a data object URI (if we are talking about
a commonly used Linked Data pattern, then URL above would be conduit to the EAV
model based representation of the description of this data object)
And the semantics of a fragment means that
http://example.org/something#a is a secondary resource, where
http://example.org/something is the primary resource (?)
Sorta.
Then if I delete a Primary resource, the secondary resources must also
be deleted, true / false (?).
Not necessarily, this really depends on the Linked Data pattern you've
adopted re. generic HTTP URIs. Basically, the pattern you've adopted
such that that you to Reference a Data Object and Access a
Representation of its Description via a single URI.
Here are some examples, which may seem like over kill but some are
interesting and generally I *feel* rules like this should be either
always true, or always false, never varying.
examples:
if I remove a database table, then all it's rows also no longer exist.
if I remove London then the Tower of London also no longer exists.
if somebody removes me, then my arms also no longer exist.
if I remove test.html then test.html#whatever no longer exists.
if I remove test.rdf then test.rdf#this no longer exists
if I remove http://www.w3.org/People/Berners-Lee/card then
http://www.w3.org/People/Berners-Lee/card#i no longer exists.
No, you've lost access to description of:
<http://www.w3.org/People/Berners-Lee/card#i>, of course it still exists
:-)
conversely:
if I remove a row, the table still exists
if I remove the Tower of London, London still exists
if you remove my arms, I still exists and I'll find another way to type.
if I remove test.html#whatever test.html still exists
if I remove test.rdf#this, test.rdf still exists
if I remove http://www.w3.org/People/Berners-Lee/card#i then
http://www.w3.org/People/Berners-Lee/card still exists.
How do you remove: <http://www.w3.org/People/Berners-Lee/card#i> ? Let's
say you take it out of <http://www.w3.org/People/Berners-Lee/card>, then
for agents that seek description of
<http://www.w3.org/People/Berners-Lee/card#i> via aforementioned URL,
you get nothing. Nothing stops the
<http://www.w3.org/People/Berners-Lee/card#i> description existing in my
linked data space :-)
If the above is true (secondary resource must also be deleted on removal
of primary resource),
Not true .
then I should never use a fragment Identifier to
refer to a non-virtual object (i.e. "me" a Person) - because I can't be
deleted by simply removing a resource. (?)
Best to think about the issue of "Identifier" as absolutely distinct
from "Representation".
Links:
1.
http://www.cs.cmu.edu/afs/cs.cmu.edu/user/clamen/OODBMS/Manifesto/htManifesto/node4.html
-- might come in handy re. Identifier matters .
Kingsley
Regards!
Nathan
--
Regards,
Kingsley Idehen
President & CEO
OpenLink Software
Web: http://www.openlinksw.com
Weblog: http://www.openlinksw.com/blog/~kidehen
Twitter/Identi.ca: kidehen
