Re: Considering a PATCH model for LDP

I agree with Andy regarding global names, and their replacement by
predicates.

I also agree that the examples with bnodes in [1] are problematic,
and that bnodes should probably not be allowed in the DELETE part.
After all, we can still use PUT for this situation.

  pa

[1] - http://open-services.net/wiki/core/OSLC-Core-Partial-Update/


On Mon, Mar 11, 2013 at 2:25 PM, Andy Seaborne <
andy.seaborne@epimorphics.com> wrote:

> Because you are labelling/naming the graph in a local context (the file)
> with a global name.
>
> I disagree with:
> """
> A pre-defined named graph that represents the nodes to match or to
> insert is sufficient.
> """
>
> Your 'oslc:deleteGraph' graph isn't my 'oslc:deleteGraph'.
>
> Test:
> What description would I get if deference GET oslc:deleteGraph?
>
> You are proposing using fixed, well known names as syntax to construct
> the change operation. Using keywords seems more appropriate.
>
> - - - - - - - - - - - -
>
> All changeset proposals need also to deal with deleting bNodes -
>
> oslc:deleteGraph {
> _:b1 dcterms:title "A bad link title";
>     rdf:object <http://myserver/mycmapp/bugs/1235>;
>     rdf:predicate oslc_cm:relatedChangeRequest;
>     rdf:subject <http://example.com/bugs/2314>;
>     a rdf:Statement.
> }
>
> in TriG does not delete a triple with property dcterms:title.  _:b1 is
> label just within the file, and not the resource. On parsing you get
> different bNodes each time the file is read.
>
> What's the proposal here?
>
> DELETE DATA does not allow bNodes in the data specifically because of
> the meaninglessness.
>
> You may which to consider DELETE WHERE {} which allows named variables
> (but not bNodes).  DELETE WHERE {} is a shorthand for
>
> DELETE {template} WHERE {pattern}
>
> with template=pattern.
>
>         Andy
>
> On 11/03/13 12:48, Steve Speicher wrote:
> > On Sun, Mar 10, 2013 at 3:55 PM, Andy Seaborne
> > <andy.seaborne@epimorphics.com> wrote:
> >> The use of global names for the actions on the graphs can be avoided by
> >> including a manifest in the default graph (the way the global names are
> uses
> >> is really predicate-like).
> >>
> >> { <> ldp:insert :g1 ;
> >>       ldp:delete :g2 }
> >>
> >> :g1 { ... }
> >>
> >> :g2 { ... }
> >>
> >>          Andy
> >>
> >
> > Thanks for the feedback Andy.  You seem to imply that "global names
> > for the actions" is a bad thing, can you elaborate why this is a
> > problem and what you propose improves it?  I think I know the answer
> > but I'd rather not assume.
> >
> > Thanks,
> > Steve
> >
> >>
> >> On 09/03/13 23:34, Ashok Malhotra wrote:
> >>>
> >>> Hi Steve:
> >>> We have PATCH for JSON
> >>> http://tools.ietf.org/html/draft-ietf-appsawg-json-patch-09
> >>> and PATCH for XML: http://tools.ietf.org/html/draft-wilde-xml-patch-04
> >>>
> >>> Wouldn't your proposal be better characterized as PATCH for RDF?
> >>> So, we should have the RDF folks look at it.
> >>> All the best, Ashok
> >>> On 3/9/2013 9:35 AM, Steve Speicher wrote:
> >>>>
> >>>> We have a number of issues related to PATCH'ing resources:
> >>>> ISSUE-12 (closed) Can HTTP PATCH be used for resource creation?
> >>>> ISSUE-17 changesets as a recommended PATCH format
> >>>> ISSUE-27 Should the PATCH method be used, as opposed to POST with a
> >>>> given mime type?
> >>>>
> >>>> I have drafted something very simple that meets most of OSLC's simple
> >>>> use cases that I would like to use as a basis for discussion on a
> >>>> model for PATCH [1]. It separates the model from the document (format)
> >>>> used mostly.  It takes an approach that doesn't require SPARQL Update
> >>>> but shows how it can be used.  The patch document can be any quad
> >>>> format.
> >>>>
> >>>> Feedback welcome on this independent of usage within LDP as well.  I
> >>>> realize the proposal is incomplete and apologize for that -- I thought
> >>>> there was value in sharing what I have so far.  I'm currently working
> >>>> on some additional validation of this approach as well.
> >>>>
> >>>> [1] - http://open-services.net/wiki/core/OSLC-Core-Partial-Update/
> >>>>
> >>>> --
> >>>> - Steve Speicher
> >>>>
> >>>
> >>>
> >>
> >
>
>