W3C home > Mailing lists > Public > public-rdf-dawg@w3.org > January to March 2010

Re: Base URI in updates?

From: Andy Seaborne <andy.seaborne@talis.com>
Date: Thu, 11 Mar 2010 11:47:34 +0000
Message-ID: <4B98D856.6070707@talis.com>
To: Chimezie Ogbuji <ogbujic@ccf.org>
CC: Steve Harris <steve.harris@garlik.com>, SPARQL Working Group WG <public-rdf-dawg@w3.org>


On 09/03/2010 14:50, Chimezie Ogbuji wrote:
> My apologies.  This seemed to have slipped through the cracks.  I think the
> situation involving base URIs does need to be clarified in the text, but I
> just want to make sure we are on the same page, so I've CC'ed the WG.  There
> are (at least) two situations that need to be accounted for simultaneously:
>
> GET /rdf-graphs/employees?graph=../employee/1  HTTP/1.1
> Host: example.com
>
> PUT /rdf-graphs/employees?graph=../employee/1  HTTP/1.1
> Host: example.com
> <?xml version='1.0' encoding='UTF-8'?>
> <rdf:RDF
>    xml:base='http://example2.com/rdf-graphs/employees'
>    xmlns:rdf='...'>
> </rdf:RDF>
>
> I think we can just (normatively) refer to RFC3986 and clarify with
> examples.  For the first situation above there is no base specified in the
> content (there is no content), so the next level of precedence (Base URL of
> the encapsulating entity) would apply.  However, I don't think (with HTTP)
> that a Base URL can be specified within the request message and 5.1.2 seems
> to only apply to a situation where the payload is layered in some way.  So,
> the next level of precedence would apply (5.1.3.  Base URI from the
> Retrieval URI).  Which means the absolute URI of the graph whose
> representation will be retrieved is:
>
> http://example.com/rdf-graphs/employee/1
>
> For the second situation, 5.1.1 (Base URI embedded in content) would
> immediately apply since it is at the top of the precedence order and the
> payload has a base URI specified in it.  The absolute URI of the graph that
> will be replaced with the payload is:
>
> http://example2.com/rdf-graphs/employee/1
>
> So for scenarios where the graph parameter is used w/out content with an
> explicit xml:base, the user would need to be aware that the Base URI is the
> Base URI of the request.
>
> -- Chime

The other case is the base URI for the document received:


PUT /rdf-graphs/employees?graph=http://otherserver/consultant/56
Host: example.com
<?xml version='1.0' encoding='UTF-8'?>
<rdf:RDF
.... no base named ....
</rdf:RDF>

gets a base URI for the parsing of the RDF/XML document of 
http://otherserver/consultant/56

	Andy



>
> On 3/9/10 8:25 AM, "Andy Seaborne"<andy.seaborne@talis.com>  wrote:
>
>> This thread seems to have petered out.
>>
>> Do you plan to add something to the doc about base URIs?
>>
>> I hpoe Steve's analysis is right - the alternative is simply horrible!
>>
>> Andy
>>
>> -------- Original Message --------
>> Subject: Re: Base URI in updates?
>> Date: Fri, 5 Feb 2010 16:55:11 +0000
>> From: Steve Harris<steve.harris@garlik.com>
>> To: Andy Seaborne<andy.seaborne@talis.com>
>> CC: SPARQL Working Group<public-rdf-dawg@w3.org>
>>
>> On 5 Feb 2010, at 16:23, Andy Seaborne wrote:
>>> On 05/02/2010 15:53, Steve Harris wrote:
>>>> On 5 Feb 2010, at 15:31, Andy Seaborne wrote:
>>>>
>>>>> This arose because of baseless RDF/XML and wanting to copy them from
>>>>> the their original URL to a harvesting store.
>>>>>
>>>>> What's the base URI when using SPARQL HTTP Update when using remote
>>>>> naming (?graph=)
>>>>>
>>>>> It looks to me like it's the whole of:
>>>>>
>>>>> http://server/service?graph=http://examples/myGraph
>>>>
>>>> FWIW, in 4store it's<http://examples/myGraph>  in this example. In
>>>> our
>>>> experiences this more matches user expectations with regard to
>>>> relative
>>>> URIs.
>>>
>>> That's what I'd like it to be ... I don't think that HTTP allows it
>>> though :-(
>>>
>>> http://www.ietf.org/rfc/rfc1808.txt
>>> 3.  Establishing a Base URL
>>>
>>>       .----------------------------------------------------------.
>>>       |  .----------------------------------------------------.  |
>>>       |  |  .----------------------------------------------.  |  |
>>>       |  |  |  .----------------------------------------.  |  |  |
>>>       |  |  |  |   (3.1) Base URL embedded in the       |  |  |  |
>>>       |  |  |  |         document's content             |  |  |  |
>>>       |  |  |  `----------------------------------------'  |  |  |
>>>       |  |  |   (3.2) Base URL of the encapsulating entity |  |  |
>>>       |  |  |         (message, document, or none).        |  |  |
>>>       |  |  `----------------------------------------------'  |  |
>>>       |  |   (3.3) URL used to retrieve the entity            |  |
>>>       |  `----------------------------------------------------'  |
>>>       |   (3.4) Base URL = "" (undefined)                        |
>>>       `----------------------------------------------------------'
>>
>> In my (not very informed) opinion, 3.2 "Base URL of the encapsulating
>> entity" would cover this case, if it was worded correctly in the HTTP
>> update spec.
>>
>> - Steve
>
>
> ===================================
>
> P Please consider the environment before printing this e-mail
>
> Cleveland Clinic is ranked one of the top hospitals
> in America by U.S.News&  World Report (2009).
> Visit us online at http://www.clevelandclinic.org for
> a complete listing of our services, staff and
> locations.
>
>
> Confidentiality Note:  This message is intended for use
> only by the individual or entity to which it is addressed
> and may contain information that is privileged,
> confidential, and exempt from disclosure under applicable
> law.  If the reader of this message is not the intended
> recipient or the employee or agent responsible for
> delivering the message to the intended recipient, you are
> hereby notified that any dissemination, distribution or
> copying of this communication is strictly prohibited.  If
> you have received this communication in error,  please
> contact the sender immediately and destroy the material in
> its entirety, whether electronic or hard copy.  Thank you.
>
>
> ______________________________________________________________________
> This email has been scanned by the MessageLabs Email Security System.
> For more information please visit http://www.messagelabs.com/email
> ______________________________________________________________________
Received on Thursday, 11 March 2010 11:48:13 GMT

This archive was generated by hypermail 2.3.1 : Tuesday, 26 March 2013 16:15:41 GMT