Re: Content negotiation negotiation

On 23 Apr 2013, at 22:39, Kingsley Idehen <kidehen@openlinksw.com>
 wrote:

> On 4/23/13 5:04 PM, Hugh Glaser wrote:
>> Ah POWDER - of course.
>> It all comes together :-)
>> (Sorry if this is boring and obvious to others - and thanks Kingsley.)
>> So last (?!) 2 things, if I may.
>> Any proposal to attach types to the objects of the wdrs:desribedby triples?
> 
> So as in <http://ns.nature.com/docs/terms/datatypes/anyURI___279277607.html> you seek the xsd:anyURI type qualification, for objects of said relation, right? If yes, then fine, it can be added quickly.
I don't think so.
I am not after a datatype.
In fact I find datatypes particularly unhelpful in an RDF/SPARQL context, but that's another story.

What I am after is the MIME type of the different alternates that are offered for conneg.
So I can query something like
SELECT ?source FROM { <http://dbpedia.org/resource/Luton> ?foo ?file . ?file mime:application/json ?source . }
and then choose my json source.

All that wdrs:described by tells me is that there is another file, but nothing about the format.
(Of course the "json" at the end is a hint, but it is really just an opaque string.)
I could of course resolve them all, asking for json or whatever, and see what the response code/header gives me back, but I don't want to/can't really see headers in the Linked Data context. And the server provider would not thank me for the traffic.
And in any case, many servers are particularly bad at giving a 406 or whatever it is, and simply give a 200 and html.

>> Any proposal so that I can infer the available types for the whole dataset, rather than inferring from a particular resource resolution?
> 
> You mean for RDF resources such as the one denoted by <http://dbpedia.org/data/Luton.ttl> ? If yes, then we can just add the missing resource metadata relations which would basically come from VoID [1].
I mean for the whole dbpedia.org/resource dataset.
I am guessing that the range of content for most significant sites (such as dbpedia) is actually the same for all resources.
So I could build a KB that had the formats available.
In fact, I might even add it to my voiD store.
> 
> Links:
> 
> 1. http://www.w3.org/TR/void/#class-property-partitions
By the way, I can't seem to see the wdrs:describedby stuff in http://dbpedia.org/resource/Luton at the moment.

Best
Hugh
> 
> Kingsley
>> Cheers
>> 
>> On 23 Apr 2013, at 21:48, Kingsley Idehen <kidehen@openlinksw.com> wrote:
>> 
>>> On 4/23/13 4:23 PM, Hugh Glaser wrote:
>>>> Ah, thanks for the Web101 course.:-)
>>>> Sorry, I usually live in a Linked Data world, so I don't think about html stuff such as
>>>> <link rel="alternate" …
>>>> because (like the header) it doesn't appear in the RDF.
>>>> 
>>>> On 23 Apr 2013, at 20:54, Kingsley Idehen<kidehen@openlinksw.com>
>>>>  wrote:
>>>> 
>>>>>> On 4/23/13 3:39 PM, Hugh Glaser wrote:
>>>>>>>> Ah of course - thanks Mark, silly me.
>>>>>>>> So I look at the Link: header for something like
>>>>>>>> curl -L -ihttp://dbpedia.org/resource/Luton
>>>>>>>> Which gives me the information I want.
>>>>>>>> 
>>>>>>>> Anyone got any offers for how I would use Linked Data to get this into my RDF store?
>>>>>> Assuming I understand your question, the answer would depend on the capabilities of your RDF store. If it can injest RDF resource URLs you can request the formats exposed on the "Link:" responses.  If it handles SPARQL 1.1 INSERT and/or LOAD just use SPARQL.
>>>> I don't think I can use the SPARQL INSERT, etc, because it isn't RDF.
>>>> Is the <link rel="alternate" available anywhere as RDF?
>>>> It could be returned with the RDF forhttp://dbpedia.org/resource/Luton  Better still, it could be available in the voiD description (so that it is site-oriented, not resource-oriented)?
>>>> Or somewhere else?
>>>> Cheers
>>> Okay, now that <link/>, "Link:", and SPARQL aren't options, of course you can get it from the RDF that describes <http://dbpedia.org/resource/Luton>, see:
>>> http://dbpedia.org/describe/?url=http%3A%2F%2Fdbpedia.org%2Fresource%2FLuton&gp=8&go=
>>> 
>>> We use the wdrs:desribedby relation for that :-)
>>> 
>>> 
>>> 
>>> -- 
>>> 
>>> Regards,
>>> 
>>> Kingsley Idehen	
>>> Founder & CEO
>>> OpenLink Software
>>> Company Web: http://www.openlinksw.com
>>> Personal Weblog: http://www.openlinksw.com/blog/~kidehen
>>> Twitter/Identi.ca handle: @kidehen
>>> Google+ Profile: https://plus.google.com/112399767740508618350/about
>>> LinkedIn Profile: http://www.linkedin.com/in/kidehen
>>> 
>>> 
>>> 
>>> 
>>> 
>> 
>> 
> 
> 
> -- 
> 
> Regards,
> 
> Kingsley Idehen	
> Founder & CEO
> OpenLink Software
> Company Web: http://www.openlinksw.com
> Personal Weblog: http://www.openlinksw.com/blog/~kidehen
> Twitter/Identi.ca handle: @kidehen
> Google+ Profile: https://plus.google.com/112399767740508618350/about
> LinkedIn Profile: http://www.linkedin.com/in/kidehen
> 
> 
> 
> 
>

Received on Wednesday, 24 April 2013 11:09:34 UTC