On Thu, Jun 9, 2022 at 11:03 AM Martynas Jusevičius
<marty...@atomgraph.com> wrote:
>
> On Wed, Jun 8, 2022 at 12:22 PM Andy Seaborne <a...@apache.org> wrote:
> >
> >
> >
> > On 08/06/2022 09:22, Martynas Jusevičius wrote:
> > > On Tue, Jun 7, 2022 at 9:15 PM Andy Seaborne <a...@apache.org> wrote:
> > >>
> > >> On 07/06/2022 10:47, Martynas Jusevičius wrote:
> > >>> Hi,
> > >>>
> > >>> I have implemented PATCH method for the Graph Store Protocol:
> > >>> https://www.w3.org/TR/sparql11-http-rdf-update/#http-patch
> > >>>
> > >>> The PATCH is applied to a named graph. I am missing this bit however:
> > >>> " If a SPARQL 1.1 Update request is used as the RDF payload for a
> > >>> PATCH request that makes changes to more than one graph or the graph
> > >>> it modifies is not the one indicated, it would be prudent for the
> > >>> server to respond with a 422 Unprocessable Entity status."
> > >>
> > >> I read that in the context of GSP resource naming.
> > >>
> > >> ?graph=<uri>
> > >>
> > >> and so the update does not name a graph - it'll look like the default
> > >> graph in the update.
> > >>
> > >> So look for GRAPH in the update.
> > >
> > > Thanks, that makes sense. GRAPH is also easy to check.
> > >
> > > But then I need to forward the update to a triplestore that does not
> > > support PATCH.
> >
> > It's the GSP naming that matters.
> >
> > > Which means I would need to wrap INSERT/DELETE/WHERE templates into
> > > GRAPH <uri> { }.
> >
> > WITH <iri> DELETE {} INSERT {} WHERE {}
> >
> > Also: USING. And protocol.
>
> Thanks, forgot about those. I could definitely use WITH.
>
> And re. SPARQL protocol, would ?using-named-graph-uri=uri have the
> same effect as WITH <uri> in this case?
I realized ?using-named-graph-uri=uri would restrict the dataset but
still require GRAPH <uri> in the update string.
WITH <uri> on the other hand does what I need. I add it by string
manipulation -- the current code is ugly but seems to do the job:
String updateString = updateRequest.toString();
// append WITH <graphUri> before DELETE or INSERT
if (updateString.toUpperCase().contains("DELETE"))
updateString = updateString.replaceAll("(?i)" +
Pattern.quote("DELETE"), "WITH <" + graphUri + ">\nDELETE");
else
{
if (updateString.toUpperCase().contains("INSERT"))
updateString = updateString.replaceAll("(?i)" +
Pattern.quote("INSERT"), "WITH <" + graphUri + ">\nINSERT");
else throw new BadRequestException("SPARQL update contains
no DELETE or INSERT?"); // cannot happen
}
updateRequest = UpdateFactory.create(updateString);
>
> >
> > > Is there some builder code that can help with that?
> >
> > Have you looked at UpdateBuilder?
> >
>
> I looked at the Javadoc, it seems quite complicated. I'll see if I can
> avoid modifying the update string.
>
>
> > >
> > >>
> > >>> What would be the way to make sure that an update only affects a
> > >>> single specific graph?
> > >>
> > >> A dataset of one graph and no others. c.f. DatasetGraphOne but for a
> > >> single named graph and read-only dft graph.
> > >>
> > >> Or a dataset which yields read-only graphs except for the target graph.
> > >>
> > >> Or analyse the update - no GRAPH in templates if the target comes from
> > >> the URL.
> > >>
> > >>>
> > >>>
> > >>> Martynas
> > >>> atomgraph.com
