Re: A modest attempt to re-open ISSUE-20

On 3/13/13 6:54 AM, Henry Story wrote:
> On 13 Mar 2013, at 10:40, Andy Seaborne <andy.seaborne@epimorphics.com> wrote:
>
>>
>> On 13/03/13 07:10, Pierre-Antoine Champin wrote:
>>> Henry,
>>>
>>> On Wed, Mar 13, 2013 at 2:15 AM, Henry Story <henry.story@bblfish.net
>>> <mailto:henry.story@bblfish.net>> wrote:
>>
>>>     The abstract syntax  specificiation allows for relative URLs:
>>>     http://www.w3.org/TR/rdf11-concepts/#rdf-documents
>>>
>>>
>>> This section is about serialization; it explicitly says "concrete syntaxes".
>>> On the other hand, the definition of IRI for the graph model
>>>
>>> http://www.w3.org/TR/rdf11-concepts/#dfn-iri
>>>
>>> explicitly says "IRIs in the RDF abstract syntax MUST be absolute".
>> Yes.
>>
>> A syntax may allow a relative URI but that's in a document and a document has a base URI.  The relative URI is relative to some base URI.  Relative URI have a role in syntax
>>
>> RFC 3986 makes it clear:
>>
>> [[
>> 5.1.  Establishing a Base URI
>>
>>    The term "relative" implies that a "base URI" exists against which
>>    the relative reference is applied.  Aside from fragment-only
>>    references (Section 4.4), relative references are only usable when a
>>    base URI is known.
>> ]]
> And indeed they are: when you POST content the server will know what
> URIs the relative ones are referring to, once he has created the resource.
>
> Just a little further down in the spec one reads
>
> [[
> 5.1.4.  Default Base URI
>
>
>     If none of the conditions described above apply, then the base URI is
>     defined by the context of the application.  As this definition is
>     necessarily application-dependent, failing to define a base URI by
>     using one of the other methods may result in the same content being
>     interpreted differently by different types of applications.
>
>     A sender of a representation containing relative references is
>     responsible for ensuring that a base URI for those references can be
>     established.  Aside from fragment-only references, relative
>     references can only be used reliably in situations where the base URI
>     is well defined.
> ]]
>
> So when the client POSTs to an LDPC the client ensures that the base
> URI for the resources can be established: it is posting to an LDPC, and
> the contract is that the LDPC when POSTed to creates a new resource with a
> Location: header.
>
> This all works fine currently.

+1

Links:

1. http://lists.w3.org/Archives/Public/public-lod/2013Mar/0042.html -- 
thread from LOD list about ORCID and Linked Data deployment 
(demonstrates the value of relative URLs)
2. http://bit.ly/MYLsMu -- DIY Linked Data Deployment via Dropbox .
3. http://bit.ly/MgSz3F -- Ditto via Amazon S3 bucket .

>
>> 	Andy
>>
> Social Web Architect
> http://bblfish.net/
>


-- 

Regards,

Kingsley Idehen	
Founder & CEO
OpenLink Software
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