atom feed151 messages in org.w3.public-lodRe: Is 303 really necessary?
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NathanNov 5, 2010 3:57 am 
Ian DavisNov 5, 2010 3:59 am 
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Mischa TuffieldNov 5, 2010 4:47 am 
Norman GrayNov 5, 2010 5:11 am 
Dave ReynoldsNov 5, 2010 5:38 am 
NathanNov 5, 2010 5:52 am 
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Vasiliy FaronovNov 5, 2010 6:00 am 
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NathanNov 5, 2010 7:18 am 
David WoodNov 5, 2010 7:18 am 
Pat HayesNov 5, 2010 7:27 am 
Ian DavisNov 5, 2010 8:12 am 
Kingsley IdehenNov 5, 2010 8:18 am 
NathanNov 5, 2010 8:40 am 
Kingsley IdehenNov 5, 2010 9:36 am 
Pat HayesNov 5, 2010 10:29 am 
Kingsley IdehenNov 5, 2010 10:31 am 
NathanNov 5, 2010 10:37 am 
Hugh GlaserNov 5, 2010 10:50 am 
David BoothNov 6, 2010 1:42 pm 
Norman GrayNov 6, 2010 3:45 pm 
Kingsley IdehenNov 6, 2010 4:08 pm 
David BoothNov 7, 2010 10:27 pm 
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Tore ErikssonNov 7, 2010 11:18 pm 
Toby InksterNov 8, 2010 12:37 am 
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David BoothNov 8, 2010 6:40 am 
David BoothNov 8, 2010 6:42 am 
Norman GrayNov 8, 2010 7:51 am 
Toby InksterNov 8, 2010 8:03 am 
David BoothNov 8, 2010 12:34 pm 
Lars HeuerNov 8, 2010 1:17 pm 
David BoothNov 8, 2010 1:35 pm 
Dave ReynoldsNov 8, 2010 1:50 pm 
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Tore ErikssonNov 8, 2010 5:51 pm 
Dave ReynoldsNov 9, 2010 6:36 am 
Lars HeuerNov 9, 2010 8:00 am 
Kjetil KjernsmoNov 10, 2010 7:13 am 
Jason BorroNov 11, 2010 11:47 am 
David BoothNov 18, 2010 2:10 pm 
Kingsley IdehenNov 19, 2010 4:26 am 
David BoothNov 19, 2010 1:55 pm 
Kingsley IdehenNov 19, 2010 2:07 pm 
NathanNov 19, 2010 2:57 pm 
Kingsley IdehenNov 19, 2010 5:55 pm 
21 later messages
Subject:Re: Is 303 really necessary?
From:Kingsley Idehen (kide@openlinksw.com)
Date:Nov 6, 2010 4:08:13 pm
List:org.w3.public-lod

On 11/6/10 4:42 PM, David Booth wrote:

httpRange-14 requires that a URI with a 200 response MUST be an IR;

^^^^^^^ Not quite. The httpRange-14 decision says that the resource *is* an IR: http://lists.w3.org/Archives/Public/www-tag/2005Jun/0039

a URI with a 303 MAY be a NIR.

Ian is (effectively) suggesting that a URI with a 200 response MAY be an IR, in the sense that it is defeasibly taken to be an IR, unless this is contradicted by a self-referring statement within the RDF obtained from the URI.

To be clear, Ian's toucan URI *does* identify an information resource, whether or not it *also* identifies a toucan:

$ curl -I 'http://iandavis.com/2010/303/toucan' HTTP/1.1 200 OK Date: Sat, 06 Nov 2010 20:05:57 GMT Server: Apache/2.2.8 (Ubuntu) DAV/2 SVN/1.4.6 PHP/5.2.4-2ubuntu5.10 with Suhosin-Patch mod_wsgi/1.3 Python/2.5.2 Content-Location: toucan.rdf Vary: negotiate TCN: choice Last-Modified: Fri, 05 Nov 2010 09:24:27 GMT ETag: "264186-403-4944ad745a8c0;4944ad754eb00" Accept-Ranges: bytes Content-Length: 1027 Content-Type: application/rdf+xml; qs=0.9

Thus, Ian has created an ambiguity by returning a 200 response. There is nothing fundamentally wrong with this, as ambiguity of resource identity is inescapable anyway, and we just have to learn to deal with it. However, for those applications that need to distinguish between the toucan and its web page, Ian is effectively suggesting the *heuristic* that if the content served in the 200 response says that the URI identifies a toucan, then the app should ignore the fact that the URI also identifies a web page, and treat the URI as though it *only* identifies the toucan.

David,

What about this:

1. a 200 OK response infers that a URI is a URL (an Address) since its an indication of that a Resource has been located

2. existence of a self-describing resource discovered via "Content-Location" header value (e.g. touscan.rdf) can result in an override if the data states that the URI is a Name.

I really think we have to emphasize the "Address" and "Name" aspects of a generic URI, at every opportunity. Personally, I think it helps understand what the actual ambiguity is about.

This option showcases good RDF dog-fooding, especially as the Semantic Web Project has always been about self-describing data :-)

Regards,