Re: LDP agenda for 28 July 2014

> read 1. the added paragraph about SPARQL at the end of introduction,

AlexAndrei, a potential fly in the ointment is RFC 5789 (Patch)'s erratum 
3169 [1] hitting section 2 (pasted below).  It might be worth asking mnot 
for an opinion as to whether or not SPARQL Update's media type 
registration [2] fits within it.  The registration (indeed, the entire 
Rec) does not specifically mention Patch, which the erratum might be read 
to require.  It is a bit perverse that a media type whose whole purpose in 
life is to define update instructions on [one class of] Web-accessible 
resources might be prevented from being used in Patch because of this 
erratum.

OTOH, the link from SU [2]'s Conformance section to the SPARQL Graph Store 
Protocol document [3] (which *does* mention Patch but informatively [it 
mocks you Sandro, it mocks you], ouch) might be sufficient to satisfy the 
erratum.

It should say:
   If
   the operation does not modify the resource identified by the Request-
   URI in a predictable way that's defined by the semantics of the PATCH 
   media type, POST should be considered instead of PATCH or PUT.


[Also, I suggest adding this to section two, after the sixth paragraph:]

   The means of applying a PATCH request to a resource's state is
   determined by the request's media type.  If a server receives a PATCH
   request with a media type whose specification does not define
   semantics specific to PATCH, the server SHOULD reject the request by
   returning the 415 Unsupported Media Type status code, unless a more
   specific error status code takes priority.

   In particular, servers SHOULD NOT assume PATCH semantics for generic
   media types that don't define them, such as "application/xml" or
   "application/json".  Doing so will cause interoperability issues,
   because the semantics of PATCH become specific to that resource,
   rather than general.

Notes:
RFC5789 does not explicitly tie PATCHing semantics to the media type of 
the request. This was well understood in the discussions around the 
document, and can be read between the lines in it, but it doesn't come out 
and say it. 


[1] http://www.rfc-editor.org/errata_search.php?rfc=5789
[2] http://www.w3.org/TR/sparql11-update/#conformance , App B has media 
type reg
[3] http://www.w3.org/TR/sparql11-http-rdf-update/#http-patch


Best Regards, John

Voice US 845-435-9470  BluePages
Cloud and Smarter Infrastructure OSLC Lead


bertails@gmail.com wrote on 07/31/2014 10:52:00 AM:

> From: Alexandre Bertails <alexandre@bertails.org>
> To: Arnaud Le Hors/Cupertino/IBM@IBMUS
> Cc: "public-ldp-wg@w3.org" <public-ldp-wg@w3.org>
> Date: 07/31/2014 10:52 AM
> Subject: Re: LDP agenda for 28 July 2014
> Sent by: bertails@gmail.com
> 
> All,
> 
> About "LD Patch Format - Ready for FPWD? ", please make sure you have
> and 2. the new section on pathological graphs. Those were required for
> the last meeting but we didn't have time to go through it.
> 
> Also, if we finally decide to publish a FPWD, Andrei and I are
> planning to meet within the next 2 weeks to flush the semantics in its
> entirety (we haven't settled in on the best format yet), so a second
> WD could be expected shortly after.
> 
> 
> 
> On Thu, Jul 31, 2014 at 10:40 AM, Arnaud Le Hors <lehors@us.ibm.com> 
wrote:
> > Here is the agenda for Monday:
> > http://www.w3.org/2012/ldp/wiki/Meetings:Telecon2014.07.28
> > --
> > Arnaud  Le Hors - Senior Technical Staff Member, Open Web Standards - 
IBM
> > Software Group
>