Comunica SPARQL Service RDF Metadata Extract Actor

An RDF Metadata Extract actor that extracts SPARQL Service Description metadata.

This module is part of the Comunica framework, and should only be used by developers that want to build their own query engine.

Click here if you just want to query with Comunica.

Install

$ yarn add @comunica/actor-rdf-metadata-extract-sparql-service
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Metadata entries

This actor adds the following entries to the metadata object.

• sparqlService: Value of http://www.w3.org/ns/sparql-service-description#endpoint.
• defaultGraph: Value of http://www.w3.org/ns/sparql-service-description#defaultGraph.
• defaultDataset: Value of http://www.w3.org/ns/sparql-service-description#defaultDataset.
• unionDefaultGraph: Boolean flag set when the service declares http://www.w3.org/ns/sparql-service-description#UnionDefaultGraph feature.
• basicFederatedQuery: Boolean flag set when the service declares http://www.w3.org/ns/sparql-service-description#BasicFederatedQuery feature.
• inputFormats: List of http://www.w3.org/ns/sparql-service-description#inputFormat when available.
• resultFormats: List of http://www.w3.org/ns/sparql-service-description#resultFormat when available.
• supportedLanguages: List of http://www.w3.org/ns/sparql-service-description#supportedLanguage when available.

Configure

After installing, this package can be added to your engine's configuration as follows:

{
  "@context": [
    "https://linkedsoftwaredependencies.org/bundles/npm/@comunica/actor-rdf-metadata-extract-sparql-service/^4.0.0/components/context.jsonld"
  ],
  "actors": [
    {
      "@id": "urn:comunica:default:rdf-metadata-extract/actors#sparql-service",
      "@type": "ActorRdfMetadataExtractSparqlService"
    }
  ]
}
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Config Parameters

• inferHttpsEndpoint: If HTTPS endpoints should be forcefully used if the original URL was HTTPS-based, defaults to true.