movieWithUserDataToTurtle static method

Implementation

static String movieWithUserDataToTurtle(
    Movie movie, double? rating, String? comment) {
  final triples = <URIRef, Map<URIRef, dynamic>>{};

  // Create the movie resource with all movie metadata.

  final movieResource = localNS.withAttr('movie${movie.id}');
  triples[movieResource] = {
    rdfType: movieType,
    identifier: Literal('${movie.id}', datatype: XSD.int),
    name: Literal(_escapeString(movie.title)),
    description: Literal(_escapeString(movie.overview)),
    image: Literal(_escapeString(movie.posterUrl)),
    thumbnailUrl: Literal(_escapeString(movie.backdropUrl)),
    aggregateRating: Literal('${movie.voteAverage}', datatype: XSD.double),
    datePublished:
        Literal(movie.releaseDate.toIso8601String(), datatype: XSD.dateTime),
    genre: Literal(movie.genreIds.join(',')),
  };

  // Add user's personal rating if it exists.

  if (rating != null) {
    final userRatingResource = localNS.withAttr('userRating${movie.id}');
    triples[userRatingResource] = {
      rdfType: ratingType,
      movieId: Literal('${movie.id}', datatype: XSD.int),
      value: Literal('$rating', datatype: XSD.double),
    };

    // Link the movie to the user rating.

    triples[movieResource]![localNS.withAttr('hasUserRating')] =
        userRatingResource;
  }

  // Add user's personal comment if it exists.

  if (comment != null && comment.isNotEmpty) {
    final userCommentResource = localNS.withAttr('userComment${movie.id}');
    triples[userCommentResource] = {
      rdfType: commentType,
      movieId: Literal('${movie.id}', datatype: XSD.int),
      text: Literal(_escapeString(comment)),
    };

    // Link the movie to the user comment.

    triples[movieResource]![localNS.withAttr('hasUserComment')] =
        userCommentResource;
  }

  // Define namespace bindings.

  final bindNamespaces = {'': localNS, 'schema': movieNS};

  // Add JSON backup for compatibility.

  final movieJson = jsonEncode(movie.toJson());
  final userDataJson = jsonEncode({
    'rating': rating,
    'comment': comment,
  });

  final ttlContent =
      tripleMapToTurtle(triples, bindNamespaces: bindNamespaces);
  final withJsonBackup =
      '$ttlContent\n\n# JSON_MOVIE_DATA: $movieJson\n# JSON_USER_DATA: $userDataJson';

  return withJsonBackup;
}