- From: Martynas Jusevicius <martynas@graphity.org>
- Date: Tue, 3 Apr 2012 14:24:34 +0200
- To: Sandro Hawke <sandro@w3.org>
- Cc: public-ldp@w3.org
Hey all, congrats with this milestone :) I have a few comments though -- not sure where it's best to post them, so they just follow here below. Once again, I think there are too many new conventions, which can be solved by reusing existing ones (especially in 5.1 Informative section). bp:Container class is useful -- however, it seems to serve the same purpose a sioc:Container: "Container is a high-level concept used to group content Items together. The relationships between a Container and the Items that belong to it are described using sioc:container_of and sioc:has_container properties. A hierarchy of Containers can be defined in terms of parents and children using sioc:has_parent and sioc:parent_of." http://rdfs.org/sioc/spec/#term_Container Can't this be reused or at least integrated somehow? So that the existing SIOC Linked Data "automagically" becomes (closer to being) LDBP 1.0 compliant? If DublinCore is endorsed in this document, isn't it OK to endorse a stable and widespread vocabulary such as SIOC? It is already a W3C member submission [1]. I'm not sure creating another vocabulary for such a similar purpose is a good idea. And then I think the whole approach to paging (isn't it called "pagination" in English?) is quite wrong. If you think in terms of Containers and Resources, then in my opinion they can be split into several cases: 1. Item resource, which description only includes subject URIs identical to the request URI Usually a result of DESCRIBE query. Linked Data API defines this concept as api:ItemEndpoint. 2. Container/List resource, which description includes resources other than request URI. This is what bp:Container, sioc:Container, and api:ListEndpoint is about. Description is usually a result of a (SPARQL) query, so this is where paging applies. 3. Mixed, combining #1 and #2 - e.g. DBPedia returning a description of a class plus short list of its instances As #2 (at least in my experience) is derived as a result of a CONSTRUCT query, so I think some SPARQL terms like LIMIT and OFFSET can be reused here. For example, instead of <http://example.org/netWorth/nw1/assetContainer?firstPage> a bp:Page; bp:pageOf <http://example.org/netWorth/nw1/assetContainer>; bp:nextPage <http://example.org/netWorth/nw1/assetContainer?p=2>. we could say: <http://example.org/netWorth/nw1/assetContainer?offset=0&limit=20> a bp:Page; bp:pageOf <http://example.org/netWorth/nw1/assetContainer>; bp:nextPage <http://example.org/netWorth/nw1/assetContainer?offset=20&limit=20>. I've used this approach successfully for a long time. The purpose of the Page concept is not totally clear to me -- isn't it just another Container (subset of the assetContainer)? Or better yet, since in RDF everything can be addressed unambiguously, why can't we identify query string parameters with URIs and map them directly to SPARQL query parameters? And here's where I want to bring up the SPIN vocabulary again, which allows modelling of SPARQL queries in RDF and is also a W3C member submission [3]. SPIN readily includes properties such as sp:offset and sp:limit, so we could say: <http://example.org/netWorth/nw1/assetContainer?http%3A%2F%2Fspinrdf.org%2Fsp%23offset=0&http%3A%2F%2Fspinrdf.org%2Fsp%23limit=20> a bp:Page; bp:pageOf <http://example.org/netWorth/nw1/assetContainer>; bp:nextPage <http://example.org/netWorth/nw1/assetContainer?http%3A%2F%2Fspinrdf.org%2Fsp%23offset=20&http%3A%2F%2Fspinrdf.org%2Fsp%23limit=20>. In my eyes, that would be much less ambiguous and complete the whole cycle from HTTP query strings to SPARQL query strings by reusing existing vocabularies. Martynas graphity.org [1] http://www.w3.org/Submission/2007/SUBM-sioc-spec-20070612/ [2] http://code.google.com/p/linked-data-api/wiki/API_Vocabulary [3] http://www.w3.org/Submission/2011/SUBM-spin-overview-20110222/ On Mon, Apr 2, 2012 at 9:15 PM, Sandro Hawke <sandro@w3.org> wrote: > The submission discussed at the workshop has now been acknowledged: > > http://www.w3.org/Submission/ > http://www.w3.org/Submission/2012/02/ > > Much thanks to W3C members IBM, DERI, EMC, Oracle, Red Hat, > SemanticWeb.com, and Tasktop, for their work on this. > > I'll link it into the proposed charter shortly. > > -- Sandro > > >
Received on Tuesday, 3 April 2012 12:25:07 UTC