On Fri, Jun 10, 2022 at 5:13 PM Martynas Jusevičius
<marty...@atomgraph.com> 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.
> >
> > > 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.
>
> It seems that it's not so easy to check for GRAPH in the update after all...
>
> What is the way to "analyse the update - no GRAPH in templates" that
> you speak of? I need to check both DELETE and INSERT templates.
>
> I thought I had found a way:
>
> updateRequest.getOperations().get(0).getDeleteAcc().getGraph()
>
> but it returns <urn:x-arq:DefaultGraphNode> for the following update,
> which probably means it doesn't do what I think it does:
>
> PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
>
> WITH <https://localhost:4443/>
> INSERT {
> GRAPH ?g {
> <https://localhost:4443/> rdf:_2 <https://localhost:4443/#whateverest> .
> }
> }
> WHERE
> { GRAPH ?g
> { ?s ?p ?o }
> }
I think I figured it out. In case anyone needs it:
public class PatchUpdateVisitor extends UpdateVisitorBase
{
private boolean containsNamedGraph = false;
@Override
public void visit(UpdateModify update)
{
update.getDeleteAcc().getQuads().forEach(quad ->
{
if (!quad.getGraph().equals(Quad.defaultGraphNodeGenerated))
containsNamedGraph = true;
});
update.getInsertAcc().getQuads().forEach(quad ->
{
if (!quad.getGraph().equals(Quad.defaultGraphNodeGenerated))
containsNamedGraph = true;
});
}
public boolean containsNamedGraph()
{
return containsNamedGraph;
}
}
>
> >
> > >
> > >
> > > Martynas
> > > atomgraph.com
