Re: rel=type or rel=profile, issue 92

Alexandre Bertails <bertails@w3.org> wrote:
>I think I can safely say (Henry please confirm :-) that Henry still
>wants to communicate the interaction model through the Link header. I
>also suspect that Henry knows that rel=type has little to do with
>rdf:type because there is no explicit connection made in RFC 6903 [1].
>
>That being said, I believe that there is something interesting in what
>Henry is trying to say (if I understand correctly):
>
>* rel=type is about the resource itself, by saying that the [[ context
>   resource is an instance of the [target] resource ]], while
>
>* rel=profile is more about the [[ resource representation ]].
>
>So it looks like the two Link headers are not _about_ the same
>thing. 

That's a horrifying prospect.    Double checking RFC 5988, it seems clear that the link header is always about links (relations) between the resources, so any sense otherwise in the definition of rel=profile and likely a confusion.

I also totally understand why one would consider that
>communicating the interaction model would fall under the [[ additional
>semantics ]] that RFC 6906 talks about, that was my initial
>reading. It would also be better if RFC 6906 was specifically
>mentioning "extending the interaction model" as a use-case.
>

>So while ISSUE-92 mentions that [[ there is no mention of interaction
>constraints being conveyed [by rel=type] ]], it's also true that
>rel=profile seems more focused on the resource representation and is
>not explicit about interaction constraints.
>
>Anyway, I think that Henry brought a reasonable question that was not
>answered by the group, it would be good if Erik Wilde could help us
>understand how exactly RFC 6903 differs from RFC 6906. Maybe RFC 6906
>could be updated?
>
>Until then, I would personally not be against keeping rel=type nor
>going with rel=profile.
>

Excellent, then unless else someone comes forward with a formal objection to using link rel=type to signify ldp resource types, we're decided (since Henry was formally objecting on the other side of this issue).

  - Sandro

>Finally, I'd suggest Henry not to make his arguments using RDF if the
>reasoning is not about RDF (it was about spec interpretation
>here). People missed your point because they thought you were
>rejecting the recent accepted proposals, while you said that you're ok
>with the status quo.
>
>Cheers,
>Alexandre.
>
>[1] http://tools.ietf.org/html/rfc6903#section-6
>[2] http://tools.ietf.org/search/rfc6906
>
>On 01/18/2014 03:41 AM, Henry Story wrote:
>>
>> On 18 Jan 2014, at 03:38, Arnaud Le Hors <lehors@us.ibm.com> wrote:
>>
>>> Just to clarify: The status quo allows one to have on an LDPC either
>one of the following two headers:
>>>
>>> Link: <http://www.w3.org/ns/ldp/Container>; rel="type"
>>> Link: <http://www.w3.org/ns/ldp/Resource>; rel="type"
>>>
>>> Are you saying you're happy with that?
>>
>> I thought we had agreed that an LDPC had to have the second header.
>> And indeed that is confirmed by the comment at the end of
>>    http://www.w3.org/2012/ldp/track/issues/91
>>
>>> I thought you said you would consider it to be a bug if the latter
>was found on an LDPC. Yet, considering this a bug would make it
>impossible to legitimately address Alexandre's use case: having an LDPC
>without it's associated interaction.
>>
>> There are two ways a triple { <> a ldp:Container } can be found in a
>request to a resource: in the body or in the header.
>> Let's look at each case:
>>
>> (a) if it appears in the body:
>>    + if the resource acts like an LDPC then the statement { <> a
>ldp:Container } is true
>>    + if the resource does not act like an LDPC then the statement {
><> a ldp:Container } is false
>>
>> (b) if it appears in the header in the form of
>>         Link: <http://www.w3.org/ns/ldp/Container>; rel="type"
>>    + if the resource acts like an LDPC then the Link header was
>making a true statement
>>    + if the resource does not act like an LDPC then the Link header
>was making a false statement
>>
>> Notice that there is no difference made semantically between the { <>
>a ldp:Container } statement appearing
>> in the body or the header. My only distinction is one of attribution:
>i.e. In each case I answer differently
>> the question: who is the author of the statement?
>>
>>   + The header is the place where the server makes statements
>>   + The body is a document that can be attributed to any Agent
>>
>> Since the server is the one that determines how a resource acts, it
>is the statements in the header that
>> should have priority over the statements in the body for an agent
>interpreting a response where the headers
>> and the body are inconsistent.
>>
>>    So Alexander's use case is addressed. If someone wishes to publish
>a document where the content makes the
>> false assertion that { <> a ldp:Container } but the header contains
>>      Link: <http://www.w3.org/ns/ldp/Container>; rel="type"
>> then the client should follow the guidance of the header.
>>
>> This has a number of other advantages as I pointed out:
>>   * the server need not try to check the content of an LDPC to work
>out how to interact with it.
>>    In our implementation an LDPC is represented by a directory, so
>that the RDF content of the LDPC would not be relevant.
>>   * the client can know from a HEAD or OPTIONS if a resource is an
>LDPC
>>
>>>
>>> I can actually see why you would think it's wrong to have the type
>specified at the HTTP level not match the one specified in RDF but this
>is what motivated the proposal to change to rel="profile" which you're
>opposing.
>>
>> It is wrong for a document to make a claim that it is an LDPC when it
>is not, but the
>> web will be full of false claims, and often unintentional false
>claims ( such as when a resource
>> points to another stating that it is an LDPC when it no longer is ).
>>
>> The final arbiter is how a resource acts, but a client should go by
>what the resource header says
>> in final analysis.
>>
>>>
>>> I don't understand whether you actually accept Alexandre's use case
>and how you propose to address it.
>>
>> As it is Alexander's use case is allowed and that is fine.
>>
>>
>>> --
>>> Arnaud  Le Hors - Software Standards Architect - IBM Software Group
>>>
>>>
>>> Henry Story <henry.story@bblfish.net> wrote on 01/17/2014 04:29:25
>PM:
>>>
>>>> From: Henry Story <henry.story@bblfish.net>
>>>> To: Arnaud Le Hors/Cupertino/IBM@IBMUS,
>>>> Cc: "public-ldp-wg@w3.org Working Group" <public-ldp-wg@w3.org>,
>Tim
>>>> Berners-Lee <timbl@w3.org>
>>>> Date: 01/17/2014 04:30 PM
>>>> Subject: Re: rel=type or rel=profile, issue 92
>>>>
>>>>
>>>> On 17 Jan 2014, at 23:45, Arnaud Le Hors <lehors@us.ibm.com> wrote:
>>>>
>>>>> Henry, this is not crazy. This is simply a practical way of making
>>>> progress. We have two sets of people reading the text to mean
>>>> different things.
>>>>
>>>> There was no serious reading of the RFC6906 text at any point yet
>in
>>>> this discussion.
>>>> I quoted two extracts of the RFC at length here:
>>>>
>>>>    
>http://lists.w3.org/Archives/Public/public-ldp-wg/2014Jan/0060.html
>>>>
>>>> and could not find anything there that explained how this relation
>>>> could in any way solve
>>>> the problems put forward here and for which the rel=profile link
>was
>>>> meant to be an answer.
>>>> I have not had anyone contradict my reading yet.
>>>>
>>>>> Not withstanding the fact that one of these two sets counts
>>>> everyone in the WG but you and the other is a singleton called
>Henry,
>>>>
>>>> That was last week when I asked for more time to review the
>>>> proposal. Since then I have
>>>> looked a lot more carefully at the issues, I have read in detail
>the
>>>> RFC 6906, and have
>>>> discussed with a number of people openly on this list. I think we
>>>> have made good progress,
>>>> and I don't think that I am alone in my doubts any more.
>>>>
>>>>> why isn't it reasonable to turn to the author to arbitrate and
>>>> tell us whether the proposed use is in the spirit of the spec or
>not?
>>>>
>>>> The author can point to spec text, and explain how he believes this
>>>> applies to what
>>>> we are doing. But he is not an impartial player in this debate as
>he
>>>> wrote the text.
>>>>
>>>> The text of RFC 6906 combined with a description of our alleged
>problem has
>>>> to be the basis on which we come to a decision on this.
>>>>
>>>> I don't see furthermore how one can accuse me of holding up a
>>>> process, since I am
>>>> the one arguing here that the current spec is fine, and am
>defending
>>>> the status quo.
>>>>
>>>> Henry
>>>>
>>>>
>>>>> --
>>>>> Arnaud  Le Hors - Software Standards Architect - IBM Software
>Group
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> From:        Henry Story <henry.story@bblfish.net>
>>>>> To:        Arnaud Le Hors/Cupertino/IBM@IBMUS,
>>>>> Cc:        "public-ldp-wg@w3.org Working Group" <public-ldp-
>>>> wg@w3.org>, Tim Berners-Lee <timbl@w3.org>
>>>>> Date:        01/17/2014 02:18 PM
>>>>> Subject:        Re: rel=type or rel=profile, issue 92
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> On 17 Jan 2014, at 22:44, Arnaud Le Hors <lehors@us.ibm.com>
>wrote:
>>>>>
>>>>>> John already reported that he checked with Erik Wilde on the
>>>> proposed use of rel=profile for the purpose at hand and that Erik
>>>> said it was fine. Why can't we accept the opinion of the very
>author
>>>> of the relevant RFC rather than try to second guess what the text
>>>> was meant to allow or not?
>>>>>
>>>>> You're joking right?
>>>>>
>>>>> The text of an RFC is primary over the opinion of its author. It
>>>> is the text that will be
>>>>> used and referred to by developers in the future. We are
>>>> discussing what type of relation
>>>>> we want in the LDP spec, and for this we need to look at the text
>>>> published here:
>>>>>
>>>>>     http://tools.ietf.org/search/rfc6906
>>>>>
>>>>> If the author could not get his thoughts through in this text,
>>>> then there is no second
>>>>> guessing.
>>>>>
>>>>>> Sorry but we just don't have time for this type of debate
>>>> anymore. THAT is not constructive.
>>>>>
>>>>> This is crazy! Allowing this type of reasoning would be to akin to
>>>>> writing blank checks in standards body.
>>>>>
>>>>> Henry
>>>>>
>>>>>
>>>>>> --
>>>>>> Arnaud  Le Hors - Software Standards Architect - IBM Software
>Group
>>>>>>
>>>>>>
>>>>>> Henry Story <henry.story@bblfish.net> wrote on 01/17/2014
>01:21:00 PM:
>>>>>>
>>>>>>> From: Henry Story <henry.story@bblfish.net>
>>>>>>> To: Arnaud Le Hors/Cupertino/IBM@IBMUS,
>>>>>>> Cc: "public-ldp-wg@w3.org Working Group" <public-ldp-wg@w3.org>
>>>>>>> Date: 01/17/2014 01:21 PM
>>>>>>> Subject: Re: rel=type or rel=profile, issue 92
>>>>>>>
>>>>>>>
>>>>>>> On 17 Jan 2014, at 20:24, Arnaud Le Hors <lehors@us.ibm.com>
>wrote:
>>>>>>>
>>>>>>>> "Eric Prud'hommeaux" <ericw3c@gmail.com> wrote on 01/17/2014
>>>> 10:45:25 AM:
>>>>>>>>
>>>>>>>>> Apart from how we would best model types vs. interaction
>models, we
>>>>>>>>> are good netizens who use HTTP headers as the are intended,
>and
>>>>>>>>> rel=profile is intended to communicate the interaction model.
>>>>>>>>
>>>>>>>> The fundamental question is (again) whether we agree that the
>>>>>>> interaction model isn't tied to the RDF data type and whether
>>>>>>> Alexandre's use case - allowing one to have a container that
>doesn't
>>>>>>> behave like an LDPC but a mere LDPR - is legit and should be
>supported.
>>>>>>>>
>>>>>>>> If we don't agree with that - and Henry apparently doesn't -
>>>>>>> discussing how it should be supported is rather moot.
>>>>>>>>
>>>>>>>> Given the amount of discussion that has already taken place
>over
>>>>>>> this question - this is just a new occurence, it's not really
>>>>>>> different from the discussion around mediatypes we had earlier
>on -
>>>>>>> I see little hope to get consensus on this unfortunately. It's
>like
>>>>>>> discussing politics or religion - people don't typically
>>>> change their mind.
>>>>>>>
>>>>>>> Frankly dismissing arguments as religious is not very
>constructive.
>>>>>>> Precise arguments
>>>>>>> were made that are eminently falsifiable.
>>>>>>>
>>>>>>> I have made a few:
>>>>>>>
>>>>>>>    a) that rel="profile" as specified in rfc6906 makes no
>mention of
>>>>>>> interaction models.
>>>>>>>     => This can be falsified by pointing to relevant sections of
>the wiki
>>>>>>>
>>>>>>>    b) that the archiving problem could be applied just as well
>to any
>>>>>>> relation to interaction
>>>>>>>       models,  so that the argument about moving to a relation
>won't
>>>>>>> solve the problem
>>>>>>>      => This can be falsified by explaining how this is mistaken
>>>>>>>
>>>>>>>
>>>>>>>> Given how late we are already with regard to our schedule we
>can't
>>>>>>> afford to spend more airtime discussing this.
>>>>>>>>
>>>>>>>> This leaves us with two options: 1) give up on supporting
>>>>>>> Alexandre's use case, 2) overrule Henry's objection and proceed,
>>>>>>> leaving it to him to decide whether he wants to file a formal
>>>> objection.
>>>>>>>>
>>>>>>>> Please, be prepared to vote on those options.
>>>>>>>>
>>>>>>>> Regards.
>>>>>>>> --
>>>>>>>> Arnaud  Le Hors - Software Standards Architect - IBM Software
>Group
>>>>>>>>
>>>>>>>
>>>>>>> Social Web Architect
>>>>>>> http://bblfish.net/
>>>>>>>
>>>>>
>>>>> Social Web Architect
>>>>> http://bblfish.net/
>>>>>
>>>>>
>>>>
>>>> Social Web Architect
>>>> http://bblfish.net/
>>>>
>>
>> Social Web Architect
>> http://bblfish.net/
>>
>>
>>

Received on Sunday, 19 January 2014 20:44:05 UTC