rdflib 0.1.1 rdflib: ^0.1.1 copied to clipboard
A dart toolkit for organizing RDF files. Store triples, read RDF files and export to different formats.
import 'dart:io';
import 'package:rdflib/rdflib.dart';
main() async {
Graph g = Graph();
URIRef example = URIRef.fullUri('http://example.org');
// subject and predicate should be a valid URIRef instance
URIRef donna = example.slash('donna');
g.add(Triple(sub: donna, pre: RDF.type, obj: FOAF.Person));
// add duplicated record
g.add(Triple(sub: donna, pre: RDF.type, obj: FOAF.Person));
g.add(Triple(sub: donna, pre: FOAF.nick, obj: Literal('donna', lang: 'en')));
g.add(Triple(sub: donna, pre: FOAF.name, obj: Literal('Donna Fales')));
// add duplicated record
g.add(Triple(sub: donna, pre: FOAF.name, obj: Literal('Donna Fales')));
g.add(Triple(
sub: donna,
pre: FOAF.mbox,
obj: URIRef.fullUri('mailto:donna@example.org')));
// add another in the graph
URIRef ed = example.slash('edward');
g.add(Triple(sub: ed, pre: RDF.type, obj: FOAF.Person));
g.add(Triple(
sub: ed, pre: FOAF.nick, obj: Literal('ed', datatype: XSD.string)));
g.add(Triple(sub: ed, pre: FOAF.name, obj: 'Edward Scissorhands'));
g.add(Triple(
sub: ed,
pre: FOAF.mbox,
obj: Literal('e.scissorhands@example.org', datatype: XSD.anyURI)));
// TEST triples should print correctly
print('-' * 30);
for (Triple t in g.triples) {
// duplicated records will not be added and printed out
print(t);
}
print('-' * 30);
// TEST correct subjects/objects should print out
for (URIRef s in g.subjects(RDF.type, FOAF.Person)) {
for (var o in g.objects(s, FOAF.mbox)) {
// should print out URIRef(mailto:donna@example.org) and
// Literal(e.scissorhands@example.org, datatype: URIRef(http://www.w3.org/2001/XMLSchema#anyURI))
print(o);
}
}
// bind 'foaf' to FOAF for easy readout
g.bind('foaf', FOAF(ns: FOAF.foaf));
/// uncomment the following line to test binding a customized namespace
/// g.bind('example', Namespace(ns: 'http://example.org/'));
// export graph to turtle format, create directory if it doesn't exist
String currentPath = Directory.current.path;
String examplePath = '$currentPath/example';
if (!await Directory(examplePath).exists()) {
await Directory(examplePath).create(recursive: true);
}
g.serialize(format: 'ttl', dest: '$examplePath/ex1.ttl');
}