graphql-to-sparql
Version:
Converts GraphQL queries to SPARQL queries
49 lines • 2.49 kB
JavaScript
"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.NodeValueHandlerList = void 0;
const NodeValueHandlerAdapter_1 = require("./NodeValueHandlerAdapter");
/**
* Converts GraphQL lists to RDF lists if settings.arraysToRdfLists is true, otherwise it converts to multiple values.
*/
class NodeValueHandlerList extends NodeValueHandlerAdapter_1.NodeValueHandlerAdapter {
constructor(util, settings) {
super('ListValue', util, settings);
this.nodeFirst = this.util.dataFactory.namedNode('http://www.w3.org/1999/02/22-rdf-syntax-ns#first');
this.nodeRest = this.util.dataFactory.namedNode('http://www.w3.org/1999/02/22-rdf-syntax-ns#rest');
this.nodeNil = this.util.dataFactory.namedNode('http://www.w3.org/1999/02/22-rdf-syntax-ns#nil');
}
handle(valueNode, fieldName, convertContext) {
const listTerms = [];
let auxiliaryPatterns = [];
// Create terms for list values
for (const v of valueNode.values) {
const subValue = this.util.handleNodeValue(v, fieldName, convertContext);
for (const term of subValue.terms) {
listTerms.push(term);
}
if (subValue.auxiliaryPatterns) {
auxiliaryPatterns = auxiliaryPatterns.concat(subValue.auxiliaryPatterns);
}
}
if (this.settings.arraysToRdfLists) {
// Convert array to RDF list
// Create chained list structure
const firstListNode = this.util.dataFactory.blankNode();
let listNode = firstListNode;
let remaining = listTerms.length;
for (const term of listTerms) {
auxiliaryPatterns.push(this.util.operationFactory.createPattern(listNode, this.nodeFirst, term, convertContext.graph));
const nextListNode = --remaining === 0 ? this.nodeNil : this.util.dataFactory.blankNode();
auxiliaryPatterns.push(this.util.operationFactory.createPattern(listNode, this.nodeRest, nextListNode, convertContext.graph));
listNode = nextListNode;
}
return { terms: [firstListNode], auxiliaryPatterns };
}
else {
// Convert array to multiple terms that will be linked via the same predicate.
return { terms: listTerms, auxiliaryPatterns };
}
}
}
exports.NodeValueHandlerList = NodeValueHandlerList;
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