Re: Marmotta early implementation report

On Wed, Mar 12, 2014 at 7:46 AM, Sergio Fernández <
sergio.fernandez@salzburgresearch.at> wrote:

> Dear WG members,
>
> my colleague Jakob Franc (CCed) and myself have been manually reviewing
> the latest LDP Working Draft published yesterday [1], and putting together
> a detailed implementation report for Apache Marmotta [2]:
>
>
Hi Sergio and Jakob,
Thank you for this feedback, good work..  I haven't had a chance to
actually run your changes but I have responded to your questions below.


> == 4.3 RDF Source ==
>
>  * 4.3.1.6 Reuse Predicates: conforms Overlapping with 4.3.1.5?
>
Perhaps not 100%, though I could see how they could be combined but I don't
really see any hard in leaving as-is either.


> = Open Issues and Questions =
>
> == Missing Things ==
>
> 1. Update LDP Ontology http://www.w3.org/ns/ldp# with the terms missing
> from the Spec:
>    * ldp:BasicContainer
>    * ldp:contains
>    * ldp:DirectContainer
>    * ldp:hasMemberRelation
>    * ldp:IndirectContainer
>    * ldp:insertedContentRelation
>    * ldp:isMemberOfRelation
>    * ldp:member
>    * ldp:membershipResource
>    * ldp:MemberSubject
>    * ldp:PreferContainment
>    * ldp:PreferEmptyContainer
>    * ldp:PreferMembership
>    * ldp:RDFSource

We have an outstanding request to have this properly updated, for now you
can find what is supposed to be served there at: www.w3.org/TR/ldp/ldp.ttl
Apologies for the confusion and taking your time to review the outdated
content.

2. Add ldp:NonRdfResource to the Spec. and LDP-Ontology
>     (URI is never explicitly used in the Spec)
>
It is in ontology but is ldp:NonRDFSource.  I'll look to see where it
should fit in the spec.


> 3. Extra Link: Headers on Requests to LDP-R
>    * LDP-NR: Link with href of the corresponding RDF-RS with type "meta"
>
Not sure why this is considered missing, we don't use this.

>    * LDP-RS: Link with href of the corresponding RDF-NR with type
> "content" (if present)
>
Can you elaborate on where this is missing from?  I don't recall this being
something we intended to have.


>
> == Clarifications ==
>
> 1. 5.2.3.11 Is using an URI that was previously DELETEd considered
>    "re-using"? (see also 6.1.2)
>
Yes, by "using" meaning that after a successful DELETE request, and
requests on that same URI should return 404/410 and server should not
reassign a URI (reuse) if another member is created.


> 2. 5.2.3.12 (also 5.2.8.1) Link to the LDP-RS rel should be "meta" or
>    "describedby"? (ISSUE-15)
>

describedby, rel=meta doesn't exist...we were using it conversationally.


> 3. 5.2.3.12 Is the LDP-RS also "ldp:contains" by the LDPC?
>
No, not required.  Though I could see where some implementations may
maintain a LDPC on the side of these metadata LDP-RSs.


> 4. 4.2.5  When an LDP-RS is deleted and the LDP-RS is associated with
>    an LDP-NR, should the LDP-NR be deleted too? (see also 5.2.5.2)
>
Yes.


> 5. 5.2.7.1 (also 4.2.7) Is it allowed for the LDP Server to restrict
>    the properties changed by a PATCH request (analoguous to 4.2.4.1)
>
Yes, 4.2.1.6


> 6. 6.2.4 Is it allowed to modify properties of a LDPC where a LDPR was
>    deleted from, e.g. dct:modified?

I don't see anywhere where it isn't allowed.  One could expect a server
impl to auto-update this property.  Though I would only expect certain
clients serving some admin role to be allowed to modify these type of
properties.

>
> Feedback to any of those points would be very welcomed, particularly to
> the open issues and questions. A good questions now is how to automatize
> these checking by assembling a proper test suite.
>

As we are working with our own implementations that are being positioned as
LDP-extensions and interested in an automated way to test (and extend the
tests).  I will follow up on a separate thread on this, it is along the
lines of your RESTassured junits.


>
> In addition, I'd like to point that we, as well of all other potential
> implementations, would benefit of keeping the sections numbering as stable
> as possible in these last revisions of the spec.
>

Agree, we decided to move things around a bit and adopt better anchors to
help with consumption.  The intent is hopefully it will be fairly stable
from here, at least you can reference the individual sections by URI (and
not number as respec generates those section numbers).

 Steve Speicher



> For those interested to play around the implementation, please check the
> required instructions [3]. This implementation report refers to the code
> available in the ASF's git repository, commit 673ddc35dbf9bfd66df49ceb1e3db5a3ba7a238f
> [4].
>
> Cheers,
>
> [1] http://www.w3.org/TR/2014/WD-ldp-20140311/
> [2] http://wiki.apache.org/marmotta/LDPImplementationReport/2014-03-11
> [3] http://wiki.apache.org/marmotta/LDPImplementationReport#Instructions
> [4] https://git-wip-us.apache.org/repos/asf?p=marmotta.git;a=commit;h=
> 673ddc35dbf9bfd66df49ceb1e3db5a3ba7a238f
>
> --
> Sergio Fernández
> Senior Researcher
> Knowledge and Media Technologies
> Salzburg Research Forschungsgesellschaft mbH
> Jakob-Haringer-Straße 5/3 | 5020 Salzburg, Austria
> T: +43 662 2288 318 | M: +43 660 2747 925
> sergio.fernandez@salzburgresearch.at
> http://www.salzburgresearch.at
>
>