- From: Sandro Hawke <sandro@w3.org>
- Date: Tue, 25 Feb 2014 11:41:09 -0500
- To: Roger Menday <roger.menday@uk.fujitsu.com>
- CC: "henry.story@bblfish.net" <henry.story@bblfish.net>, Soiland-Reyes Stian <soiland-reyes@cs.manchester.ac.uk>, Steve K Speicher <sspeiche@gmail.com>, public-ldp <public-ldp@w3.org>
- Message-ID: <530CC7A5.5020405@w3.org>
On 02/25/2014 11:35 AM, Roger Menday wrote:
>
> On 25 Feb 2014, at 16:22, Sandro Hawke wrote:
>> On 02/25/2014 08:38 AM, henry.story@bblfish.net wrote:
>>>
>>> On 25 Feb 2014, at 11:36, Sandro Hawke <sandro@w3.org
>>> <mailto:sandro@w3.org>> wrote:
>>>
>>>> I didn't want to talk about this more since I didn't think it was
>>>> critical to the current decisions the WG has to make, but in
>>>> arguing with Henry during the meeting yesterday I expressed a
>>>> solution that I want to express here:
>>>>
>>>> Clients (and their users) doing POST are responsible only for
>>>> the statements actually made in the posted representation. If
>>>> the server chooses to publish other triples in response to the
>>>> POST, eg membership triples in the container, those are the
>>>> responsibility of the server, not the client, even if the
>>>> client had reason to believe the server would add those
>>>> membership triples in response to the POSTing.
>>>>
>>> This completely goes against the way the protocol has been built up
>>> to now.
>>
>> There are lots of different pieces built up. It doesn't
>> necessarily align with all of them, but it doesn't contradict any of
>> them.
>>
>>> It does not really make sense
>>> to have a type of container such as a ldp:DirectContainer which
>>>
>>> 1) MUST have the membership properties,
>>> 2) makes explicit the relation between those membership properties
>>> and how a POST action to the LDPC
>>> creates a membership statements.
>>>
>>> and then to say that
>>>
>>> 3) a client need only understand the content of the POSTed graph,
>>> and not the necessarily
>>> subsequent creation of the membership triple.
>>>
>>> What then would be the point of the membership triple?
>>
>> It's the difference between (1) me signing a legal form as part of
>> the process of walking into a room and (2) someone writing down the
>> names of the people in a room. In first case I'm obligated by
>> whatever the form says; in the second I'm not obligated in any way.
>> Both are things that happen in human society.
>>
>> I'm suggesting we don't *need* LDP to enforce the semantics of the
>> first. Personally, I think it's a lot more complicated to say LDP
>> requires this obligation framework.
>>
>>> It is always possible for the server to
>>> add triples somewhere else on creation of a container, without all
>>> the membership triple framework.
>>
>> Yes. The people who've argued for membership triples are not, I
>> think, arguing because they want the client to be obligated purely by
>> dint of posting an empty message. If they are, I'd like to talk
>> them out of that position.
>>
>>> A normal ldp:BasicContainer can do that.
>>>
>>>> Since I think it's good practice for the post to include the
>>>> membership triples, there wouldn't normally be any issue --
>>>> both client and server would be taking responsibility for the
>>>> membership triples.
>>>>
>>> Here you seem to be contradicting what you said above. You can't
>>> both have the client be responsible for it, and
>>> not be responsible for it.
>>
>> There is no contradiction. The client is responsible for the
>> triples in the body of its posting and thus in the representation of
>> the new Resource. The server is responsible for the triples in the
>> representation of the container. If the same triple appears in both
>> places, then both of them are accepting responsibility for it. If
>> it only appears in one, then only one of them is. If it appears in
>> neither, then, of course, neither of them is.
>>
>> The examples of membership triples we've seen are things that would
>> make sense, logically, to have in the member resource as well. If
>> they appear in both places, then both client and server would be
>> taking responsibility for them. Of course, a sensible client is only
>> going to put them there if it understands them.
>>
>> This is only part of the whole responsibility story, but I think it's
>> enough to prove clients don't need to understand membership
>> configurations in order to post.
>>
>> -- Sandro
>
> hello Sandro,
>
> I think that a client does need to understand the membership
> configurations in order to POST.
>
> Of particular importance is the configuration previously known as
> "membershipPredicate". On a page with multiple <form>s, the
> membershipPredicate can be used to figure out which <form> to complete.
>
The HTML analogy doesn't tell me enough. What are the ldp clients in
your scenario actually trying to do?
- s
> Roger
>
>
Received on Tuesday, 25 February 2014 16:41:22 UTC