- From: Sandro Hawke <sandro@w3.org>
- Date: Tue, 25 Feb 2014 13:06:36 -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: <530CDBAC.5000706@w3.org>
On 02/25/2014 12:19 PM, Roger Menday wrote: > > On 25 Feb 2014, at 16:41, Sandro Hawke wrote: >> 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? >> > > All the usual stuff: > - add a bug to a bugsystem > - add a new (sub)directory to a directory (?) > - add a new asset or liability to a networth > > I'm saying that for discovering the interaction possibilities of > an application one needs to know both what the <form> processor is > saying it will create (and how), as well as the link it will add > between the creator and the created. > Okay, can you dig a little farther into a simple one, like add-a-new-bug-report? I'd think the application would be given the URL of a software project. >From there, it would follow some sort of link like doap:bug-database to an ldp:Container, which it would presume contains bug report, since this thing was referred to as a bug database. When the user clicks 'submit new bug report', the client some RDF using some bug-describption vocabulary and POSTs it to that container. If the server accepts that, the bug is now reported. How does that fall short of what you want? -- Sandro > Roger >
Received on Tuesday, 25 February 2014 18:06:48 UTC