Re: Issue 79 ldp:contains drafted

Guys,
As indicated in the closing related note of issue-79, the resolution at 
the meeting was:

Resolution: Closed Issue-79, by adding that on creating a new member 
resource using POST, LDP servers MAY add a triple a la : <> ldp:created 
<newly_created_resource> 
See https://www.w3.org/2013/meeting/ldp/2013-06-19#resolution_6 

This is what I expect to be reflected in the spec.
--
Arnaud  Le Hors - Software Standards Architect - IBM Software Group




From:   Henry Story <henry.story@bblfish.net>
To:     John Arwe/Poughkeepsie/IBM@IBMUS, 
Cc:     public-ldp-wg@w3.org
Date:   07/08/2013 10:06 PM
Subject:        Re: Issue 79 ldp:contains drafted




On 8 Jul 2013, at 21:32, John Arwe <johnarwe@us.ibm.com> wrote:

Henry, search for -79 you should get 2 hits. 

I see in this version of 
https://dvcs.w3.org/hg/ldpwg/raw-file/default/ldp.html

[[
5.4.14 LDPCs that create new member resources may add triples to the 
container as part of member creation to reflect its factory role. LDP 
defines the ldp:contains predicate for this purpose. An LDPC that tracks 
members created through the LDPC must add a triple whose subject is the 
container's URI, whose predicate is ldp:contains, and whose object is the 
newly created member resource's URI; it may add other triples as well.
]]

[[
5.6.1 When a LDPC member resource originally created by the LDPC (for 
example, one whose representation was HTTP POST'd to the LDPC and then 
referenced by a membership triple) is deleted, and the LDPC server is 
aware of the member's deletion (for example, the member is managed by the 
same server), the LDPC server must also remove it from the LDPC by 
removing the corresponding membership triple.
]]

[[
5.6.3 When the conditions in 5.6.1 hold, and the LDPC tracks member 
resources that it created using the ldp:contains predicate, the LDPC 
server must also remove the deleted member's ldp:contains triple.
]]

I would suggest that a container is always aware of ldp:contains 
membership. Everything else should be rdfs:member : that is really the 
distinction between the two. In the case of a deleted ldp:contains 
resource the ?c ldp:contains ?r triple MUST be removed from the LDPC. In 
the case of ldp:member relations this is somewhere between a MAY and a 
SHOULD as you put it above. 


We did not discuss the case where an LDPC tracks its members via 
ldp:contains and a member is created through means outside of LDP... 
should there be a corresponding ldp:contains triple or not, and is that 
Should/Must/etc. 

The important thing about ldp:contains is that it should allow us to talk 
about things that the container created and that when a DELETE on
the resource is done, the resource is removed. 

Somehow I want to say that if the resource was created some other way that 
would have been indistinguishable
from a POST creation then this would come to the same thing. The reason to 
put this in terms of the HTTP Verbs is
that otherwise ldp:creation could end up meaning something like rdf:member 
causing this constant confusion. 

At the moment I left things as we discussed and minuted them, so LDP is 
simply silent on this case. 

My guess is that the above is enough...

thanks for the work, 

   Henry

est Regards, John

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