- From: Reto Bachmann-Gmuer <reto@gmuer.ch>
- Date: Wed, 28 May 2003 18:24:19 -0400
- To: Tim Berners-Lee <timbl@w3.org>, Bjoern Hoehrmann <derhoermi@gmx.net>
- Cc: www-tag@w3.org
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Bjoern Hoehrmann wrote: > * Reto Bachmann-Gmuer wrote: >> I think a HTTP-URI should identify a document as the abstract entity >> that all of the possible result of a http-request represent, that is >> the document independently of encoding and language. > > How would you query a webserver for a list of available representations > of the abstract entity? What if you need to reference a specific > representation? I don't think that to determine the meaning of the URI it is necessary to actually have all the results of possible http-request. If a webserver returns the image of a pipe when requesting the URI with the accept header set to image/gif and returns the image of an apple when the accept header is set image/jpeg the webserver is not behaving as expected and one of the two responses misses the actual meaning of the URI. If you agree that the webserver misbehaves you agree that the HTTP-URI identifies the document a user sees in a browser when accessing the URL independently of the content-negotiation between client and server. Tim Berners-Lee wrote: > That is a good way of running a server. that is what > is represented on our server by the URI without a ".gif". > > But it is also very useful to have a URI specifically for the GIF > version. > So the best is to have both. But use the generic one wherever you > can... I think there may be good reasons to have a URI to identify the actual bytes returned by a webserver on a specific request, however I don't think the HTTP-URI is a reasonable choice. There is no way to verify that the sentence "http://w3.org/foo.gif has 3457 bytes" is true while "http://w3.org/foo has 3457 bytes" is untrue (or of indeterminable boolean value) even if the server may return a 3457 byte image on a particular request. There should be an RDF-vocabulary to describe an http-request so that you could specify something like "urn:urn-5:jhk2345sd8a9dfa is what you get requesting http://w3.org/foo.gif sending an http-request with accept-header set to image/gif" in this case you could make the verifiable assertion "urn:urn-5:jhk2345sd8a9dfa has 3457 bytes". cheers, reto -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.7 (Darwin) iD8DBQE+1TZ7D1pReGFYfq4RAmB6AKCPQOblMKcV4FgQpdqROu6VVYkvRgCgv8j8 6YVG37cYUlHf8fL/W/g4Z3Y= =NPIv -----END PGP SIGNATURE-----
Received on Wednesday, 28 May 2003 18:24:42 UTC