Re: LDPR Interaction Model on Create

On Tue, Oct 14, 2014 at 11:43 AM, Andrei Sambra <andrei.sambra@gmail.com> wrote:
> Hi all,
>
> On Tue, Oct 14, 2014 at 11:06 AM, Steve Speicher <sspeiche@gmail.com> wrote:
>>
>> Hi Nandana,
>>
>> On Mon, Oct 13, 2014 at 9:59 AM, Nandana Mihindukulasooriya
>> <nmihindu@fi.upm.es> wrote:
>> > Hi John/SteveS,
>> >
>> > On Fri, Oct 10, 2014 at 5:50 PM, John Arwe <johnarwe@us.ibm.com> wrote:
>> >>
>> >> Moving this onto the right list for drafting a consensus response.
>> >>
>> >> > I also have a small comment that I've been meaning to send regarding
>> >> > the
>> >> > interaction model.
>> >> >
>> >> > 5.2.3.4 states that "Clients use the same syntax, that is HTTP Link
>> >> > headers, to specify the desired interaction model when creating a
>> >> > resource as servers use to advertise it on responses."
>> >> >
>> >> > I noticed that in the primer, the POST request to an LDP-BC does not
>> >> > contain a link header expressing the type of the resource to be
>> >> > created.
>> >> > That also seems to be the behaviour of test suite. However, the POST
>> >> > request to an LDP-DC *contains* the Link header Link:
>> >> > <http://www.w3.org/ns/ldp#Resource>; rel="type", while *none* of the
>> >> > examples in the LDP spec show a Link header being sent with POST
>> >> > requests.
>> >>
>> >> THAT should be fixed, for sure.
>> >> The only way a LDP client gets predictable behavior is by specifying
>> >> the
>> >> interaction model.
>> >> That's what the examples should show, period... that which is
>> >> interoperable.
>> >
>> >
>> > I'm a bit confused regarding what is the consensus regarding including
>> > the
>> > interaction model header and what to do in the primer examples on
>> > POST/Create.
>> >
>> > In a previous email SteveS mentioned "I think requiring the header on
>> > create
>> > was not intended and not desirable.  IF the header is present AND the
>> > server
>> > can honor the request, then the client overrides whatever the server
>> > would
>> > have done based on the content.  So I think that it makes complete sense
>> > for
>> > LDP servers to determine the interaction model based on the content of
>> > the
>> > creation request, with the Link header being part of that.". I thought
>> > it
>> > was more biased towards not including the header in the primer examples.
>>
>> Just stating my personal preference to "point people in the right
>> direction" instead of "entirely open".  So I'd suggest we put
>> something in BP (maybe primer) that says when client doesn't supply
>> Link: rel="type" it is impl-specific, though they could dig into the
>> content, find rdf:type to determine IM and send back Link: rel="type"
>> indicate what it picked for the newly minted URI.
>>
>> > But John's reply as well as Issue-91 suggests that we should include the
>> > type Link relation header in the POST creation requests.
>> >
>> > So shall we include the interaction model header in all the POST
>> > creation
>> > examples?
>>
>> POST creation of LDPCs, yes.  POST creation of LDPRs, no.  I'm not
>> sure what including type="LDPR" would mean when posting a LDPR to a
>>
>> LDPC, as it should not affect the already set interaction model of the
>> LDPC.  Perhaps that is some extension to indicate on a per-request to
>> a LDPC but feels a bit like it would violate what we have a MUST
>> requirements on honoring client's requested interaction model on
>> creation of the container (and would need to be expanded to other
>> operations that affect containment and membership, like DELETE).
>>
>
> I thought the rel value would always be "type" (not "LDPR") when posting an
> LDPR to an LDPC -- i.e. Link: <http://www.w3.org/ns/ldp#Resource>;
> rel="type" .
>

That was just my confusing shorthand for Link:
<http://www.w3.org/ns/ldp#Resource>; rel="type"

- Steve

> -- Andrei
>
>>
>> - Steve
>>
>> >
>> > Best Regards,
>> > Nandana
>> >
>> >
>> >
>> >
>>
>

Received on Tuesday, 14 October 2014 15:51:28 UTC