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Re: [HTTP-in-RDF] Entity class?

From: Johannes Koch <johannes.koch@fit.fraunhofer.de>
Date: Wed, 03 Mar 2010 15:24:02 +0100
Message-ID: <4B8E7102.9050108@fit.fraunhofer.de>
To: ERT WG <public-wai-ert@w3.org>
Johannes Koch schrieb:
> Hi there,
> 
> in 
> <http://lists.w3.org/Archives/Public/public-earl10-comments/2009Dec/0004.html> 
> Jonathan Rees suggested to add an Entity class to the HTTP-in-RDF 
> vocabulary. Only entity headers would be associated with resources of 
> type Entity.
> 
> I guess, the other headers would still be associated to a Message resource.
> 
> He also writes that this "would be useful in validating cache and proxy
> correctness, for example in accounting for the 'etag' header."
> 
> I do not see that this is not possible with the current approach.
> 
> Basically I see one major problem: HTTP-in-RDF represents the 
> _structure_ of HTTP things, not the _semantics_. HTTP-in-RDF is 
> header-purpose-agnostic. If we follow Jonathan's approach we have to 
> distinguish entity headers from non-entity headers.
> 
> HTTP 1.1 lists "general-header (section 4.5), request-header (section 
> 5.3), response-header (section 6.2), and entity-header (section 7.1) 
> fields". However, the IANA registry for message header field names does 
> not give any indication about this classification (because it is a 
> registry for message header field names, not _HTTP_ message header field 
> names?). Even in RFC 4229 "HTTP Header Field Registrations" there's no 
> indication.
> 
> We could assume that the entity header field names listed in HTTP 1.1 
> section 7.1 are the only field names to be classified as entity header 
> field names, meaning every field name to be registered with IANA apart 
> from these cannot be an entity header field. But I don't know if this is 
> a viable assumption.

Jonathan's approach may look like:

Message
|- Entity
|  |- MessageHeader \
|  |- MessageHeader + entity headers
|  |- MessageHeader /
|  |- Content
|- MessageHeader \
|- MessageHeader |
|- MessageHeader + non-entity headers
|- MessageHeader |
|- MessageHeader /

-- 
Johannes Koch
Fraunhofer Institute for Applied Information Technology FIT
Web Compliance Center
Schloss Birlinghoven, D-53757 Sankt Augustin, Germany
Phone: +49-2241-142628    Fax: +49-2241-142065
Received on Wednesday, 3 March 2010 14:24:37 GMT

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