RDFStreamIdentifier
The RDFStreamIdentifier plug-in exposes the basic functionalities presented in Section 3 “Publishing a Stream” of A Proposal for Publishing Data Streams as Linked Data. It writes in LarKC data layer the i-graphs and the s-graph originating from one of the streams registered in the C-SPARQL Engine.
As in the case of many other identifier plug-ins (e.g., the ?FileIdentifier), the RDFStreamIdentifier is devoted to load in the LarKC platform external data. In this specific case the external data is an RDF stream.
The following code excerpt shows a simple LarKC platform v.2.5 workflow that connects a RDFStreamIdentifier to a ?SparqlQueryEvaluationReasoner. The RDF stream to be published as Streaming Linked Data in the data layer is passed using the csparl:RDFStreamIn and the URL schema proposed in Section 3 “Publishing a Stream” of the paper. An optional parameter csparl:RDFStreamOut can be used to rename the base URL of the s-graph and the i-graphs.
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> . @prefix larkc: <http://larkc.eu/schema#> . @prefix csparql: <http://larkc.eu/csparql/schema#> . _:rdfStreamIdentifier a <urn:eu.larkc.plugin.identify.RDFStreamIdentifier> . _:reasoner a <urn:eu.larkc.plugin.SparqlQueryEvaluationReasoner> . _:rdfStreamIdentifier larkc:connectsTo _:reasoner . _:rdfStreamIdentifier larkc:hasParameter _:param1 . _:param1 csparql:RDFStreamIn "http://larkc.eu/csparql/test/in" . _:param1 csparql:RDFStreamOut "http://larkc.eu/csparql/test/out" . #Define the endpoint for this workflow. <urn:eu.larkc.endpoint.sparql.ep1> a <urn:eu.larkc.endpoint.sparql> . #Endpoints are connected to paths in the workflow. Specify the path the above endpoint refers to. <urn:eu.larkc.endpoint.sparql.ep1> larkc:links _:path . _:path a larkc:Path . #Connect the input of the path to a plugin _:path larkc:hasInput _:reasoner . #Connect the output of the path to a plugin _:path larkc:hasOutput _:reasoner .