Summary of text below: it does matter for RDF to have consistent URIs (URI with "/" is different from URI without "/"); using URIs with '/' for OL resources fits better in current web server configuration. There is content negotiation, but in July 2010 it was suggested to do it differently (it is still the same) and it is not as 'Accept'ing as I would like. ----------------------------------------------------------------------------------------------------------------------
On 13 January 2012 01:52, raj kumar <[email protected]> wrote: > > On Jan 12, 2012, at 2:18 PM, Karen Coyle wrote: > >> I don't remember at this point what this was about, presumably a >> comment that came in on the list. It MAY have been a reference to the >> URI/Ls in the namespace section of the XML. Since we can't seem to >> find a problem, I'd say we should ignore it. If it matters, it'll come >> up again. > > Ah, I remember... Yes, this is specific to Namespace URIs in RDF. > > Namespace URIs should end in either / or #, so that RDF URI Refs can be > constructed by concatenation of the Namespace URI and a local name without > adding any separators. > > This concat operation is defined here: http://www.w3.org/TR/REC-rdf-syntax/ > > Ben, can you send a pull request with only the change of appending the > trailing '/'? > > Thanks! > -raj > Hi Raj, I'm not sure I understand you here, seeing that all namespace URIs already have a trailing / or #. I was talking about other 'URI references', the URIs used to identify and make statements about resources (Works, Editions and Authors). These are not prefixes, but complete URIs. I looked through the URI RFC <http://www.ietf.org/rfc/rfc2396.txt>, but found no concrete information that <http://openlibrary.org/books/OL18215289M/> and <http://openlibrary.org/books/OL18215289M> should be interpreted as being equivalent (or that they shouldn't). Following Lee's analogy: I don't know if "Ben/" should be interpreted by RDF agents as being equivalent to "Ben". If they should, in theory the discussion about URI references with or without trailing slashes is irrelevant, even though I'd say (if they were references to me) I'd prefer "Ben". :) People on <http://answers.semanticweb.com/questions/13827/is-a-uri-with-trailing-different-from-uri-without> say the identifiers are different. So it is important to be consistent in assigning URIs to resources. RDF applications who use the current OL RDF output will not be able to link the data from the Work RDF (URIs with /) to the data from the Edition RDF (URIs without /). Following the linked data principles, it would be very nice if one can look up the URI of something and get it (e.g. electronic documents) or get more information about it (e.g. information about a person). Since the resources in the Open Library cannot be transferred via HTTP, we only want information about the resources. Redirecting requests for a non-information resource using HTTP 303 to its HTML, RDF, JSON etc representation, based on the Accept header in the request, is common. But you probably know this already. Using Wireshark I could see the redirect process happening. When I ask for <x/> I get a "303 See Other" to <x>, then when I ask for <x> I get "301 Permanently moved" to <x/Title>. This is almost what the Cool URIs document describes, only content negotiation is not used - as I wrote in a previous email, I am always redirected to the HTML representation. At this point in writing this email, I searched the list archives for "http 303" and found a two-message conversation from July 2010 about using 303 redirects to <x.rdf> instead of returning RDF/XML when requesting <x>. Err, content negotiation is already implemented? So I tried "Accept: application/rdf+xml" in a request for <x/> and was redirected to <x> and served RDF/XML. D'oh! That changes what I wanted to say. The mail conversation starts at <http://www.mail-archive.com/[email protected]/msg00198.html>. Ross Singer replies in <http://www.mail-archive.com/[email protected]/msg00199.html> that redirecting to <x.rdf> seems doable. I agree and would like this to be implemented. I would like to add that better handling of the Accept header would be welcome. If I prefer Turtle (q=1) but like RDF/XML almost the same (q=0.9), I'm redirected to the HTML with 301 permanently moved. Finally, getting back to the trailing slashes: although I don't like the aesthetics of a trailing /, with this insights, it may be easier make all URI references (to OL resources) in the RDF end with a "/". Apologies for this long answer - I hope I made myself clear, though. :) Regards, Ben >> >> kc >> _______________________________________________ Ol-tech mailing list [email protected] http://mail.archive.org/cgi-bin/mailman/listinfo/ol-tech To unsubscribe from this mailing list, send email to [email protected]
