graphdb/lib/parser/sparql-json-result-parser.js

Javascript client library supporting GraphDB and RDF4J REST API.

"use strict";

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function _classCallCheck(a, n) { if (!(a instanceof n)) throw new TypeError("Cannot call a class as a function"); }
function _defineProperties(e, r) { for (var t = 0; t < r.length; t++) { var o = r[t]; o.enumerable = o.enumerable || !1, o.configurable = !0, "value" in o && (o.writable = !0), Object.defineProperty(e, _toPropertyKey(o.key), o); } }
function _createClass(e, r, t) { return r && _defineProperties(e.prototype, r), t && _defineProperties(e, t), Object.defineProperty(e, "prototype", { writable: !1 }), e; }
function _toPropertyKey(t) { var i = _toPrimitive(t, "string"); return "symbol" == _typeof(i) ? i : i + ""; }
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function _callSuper(t, o, e) { return o = _getPrototypeOf(o), _possibleConstructorReturn(t, _isNativeReflectConstruct() ? Reflect.construct(o, e || [], _getPrototypeOf(t).constructor) : o.apply(t, e)); }
function _possibleConstructorReturn(t, e) { if (e && ("object" == _typeof(e) || "function" == typeof e)) return e; if (void 0 !== e) throw new TypeError("Derived constructors may only return object or undefined"); return _assertThisInitialized(t); }
function _assertThisInitialized(e) { if (void 0 === e) throw new ReferenceError("this hasn't been initialised - super() hasn't been called"); return e; }
function _isNativeReflectConstruct() { try { var t = !Boolean.prototype.valueOf.call(Reflect.construct(Boolean, [], function () {})); } catch (t) {} return (_isNativeReflectConstruct = function _isNativeReflectConstruct() { return !!t; })(); }
function _getPrototypeOf(t) { return _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf.bind() : function (t) { return t.__proto__ || Object.getPrototypeOf(t); }, _getPrototypeOf(t); }
function _inherits(t, e) { if ("function" != typeof e && null !== e) throw new TypeError("Super expression must either be null or a function"); t.prototype = Object.create(e && e.prototype, { constructor: { value: t, writable: !0, configurable: !0 } }), Object.defineProperty(t, "prototype", { writable: !1 }), e && _setPrototypeOf(t, e); }
function _setPrototypeOf(t, e) { return _setPrototypeOf = Object.setPrototypeOf ? Object.setPrototypeOf.bind() : function (t, e) { return t.__proto__ = e, t; }, _setPrototypeOf(t, e); }
var ContentParser = require('../parser/content-parser');
var RDFMimeType = require('../http/rdf-mime-type');
var QueryType = require('../query/query-type');
var _require = require('sparqljson-parse'),
  SparqlJsonParser = _require.SparqlJsonParser;
var DataFactory = require('n3').DataFactory;

/**
 * Parse a sparql tuple query json result and convert it RDFJS-based
 * data structure.
 *
 * A custom parser library is used for the parsing. Also the N3 DataFactory is
 * used for building the data objects instead of the native RDFJS datafactory as
 * there are some minor discrepancies in between them and we already stuck to N3
 * as a default implementation.
 *
 * @class
 * @author Mihail Radkov
 * @author Svilen Velikov
 */
var SparqlJsonResultParser = /*#__PURE__*/function (_ContentParser) {
  /**
   * @param {Object} config is an object containing the parser configuration.
   */
  function SparqlJsonResultParser(config) {
    var _this;
    _classCallCheck(this, SparqlJsonResultParser);
    _this = _callSuper(this, SparqlJsonResultParser, [config]);
    _this.parser = new SparqlJsonParser({
      dataFactory: DataFactory
    });
    return _this;
  }

  /**
   * This method should be invoked with a text stream and will return also a
   * stream converted to RDFJS objects.
   *
   * Client of the method can subscribe to following events in order to consume
   * the stream:
   * <code>
   * stream.on('variables', (variables) => console.log(variables));
   * stream.on('data', (bindings) => console.log(bindings));
   * stream.on('error', (error) => console.log(error));
   * </code>
   *
   * @param {NodeJS.ReadableStream} stream with the text which has to be parsed
   * to given format.
   * @param {Object} [config] optional parser configuration.
   * @return {NodeJS.ReadableStream|Promise<boolean>} a stream with the
   * converted content for SELECT queries and a Promise which resolves to
   * boolean value for ASK queries.
   */
  _inherits(SparqlJsonResultParser, _ContentParser);
  return _createClass(SparqlJsonResultParser, [{
    key: "parse",
    value: function parse(stream, config) {
      if (config.queryType === QueryType.ASK) {
        return this.parser.parseJsonBooleanStream(stream);
      }
      return this.parser.parseJsonResultsStream(stream);
    }

    /**
     * @inheritDoc
     */
  }, {
    key: "getSupportedType",
    value: function getSupportedType() {
      return RDFMimeType.SPARQL_RESULTS_JSON;
    }

    /**
     * @inheritDoc
     */
  }, {
    key: "isStreaming",
    value: function isStreaming() {
      return true;
    }
  }]);
}(ContentParser);
module.exports = SparqlJsonResultParser;