quadstore-http

quadstore-http exposes quadstore's features via HTTP endpoints.

Current version

Current version: v6.0.1 [See on NPM].

quadstore-http is maintained alongside quadstore and versioned accordingly. Equal major version numbers imply compatibility between the two modules.

Notes

• Uses Semantic Versioning. Pre-releases are tagged accordingly.
• The master branch is kept in sync with NPM and all development work happens on the devel branch and/or issue-specific branches.
• Requires Node.js >= 8.0.0.

Usage

HttpServer

The exported HttpServer class extends http.Server and requires instances of both quadstore.RdfStore and quadstore-sparql:

  const memdown = require('memdown');
  const quadstore = require('quadstore');
  const SparqlEngine = require('quadstore-sparql');
  const HttpServer = require('quadstore-http');

  const db = memdown();
  const rdfStore = new quadstore.RdfStore(db);
  const sparqlEngine = new SparqlEngine(rdfStore);
  const opts = {
    baseUrl: 'http://127.0.0.1:8080'
  };
  const server = new HttpServer(rdfStore, sparqlEngine, opts);

  server.listen(8080, '127.0.0.1', (err) => {
    if (err) throw err;
    console.log(`Listening!`);
  });

GET /match

Mirrors RDF/JS's Source.match() method. Returns quads serialized either in application/n-quads or application/trig matching the specified query parameters.

Supported parameters are subject, predicate, object, graph, offset and limit.

GET http://127.0.0.1:8080/match?subject=<value>&offset=10&limit=10

Values for the subject, predicate, object and graph parameters must be serialized using Ruben Verborgh's N3 library and must be urlencoded.

POST /import

Mirrors RDF/JS's Sink.import() method. Accepts a payload of quads serialized either in application/n-quads or application/trig and imports them into the store.

POST http://127.0.0.1:8080/import

This endpoint parses RDF payloads using the N3 library. N3's default behaviour is to prefix blank node labels with a b{digit}_ prefix, with the {digit} part being a positive number that grows with each new import. This is done to prevent naming collisions of unrelated blank nodes and can be disabled by setting the blank-node-prefix query parameter to an empty string:

POST http://127.0.0.1:8080/import?blank-node-prefix=

POST /delete

Mirrors RDF/JS's Store.delete() method. Accepts a payload of quads serialized either in application/n-quads or application/trig and deletes them from the store.

POST http://127.0.0.1:8080/delete

GET /ldf

Provides a Linked Data Fragments endpoint implementing the Triple Pattern Fragments (TPF) interface for use with suitable clients.

GET http://127.0.0.1:8080/ldf?page=2

In order to support quads instead of triples, this endpoint is tested using our own fork of the Client.js library. The fork tracks the feature-qpf-latest branch of the upstream repository and merges in fixes from other branches. We will switch to the NPM version of Client.js (ldf-client) in the near future.

GET,POST /sparql

Provides a SPARQL 1.1 Protocol endpoint be used with suitable clients.