File indexing completed on 2024-11-24 04:44:39 

0001 /*
0002  * SPDX-FileCopyrightText: 2021 Volker Krause <vkrause@kde.org>
0003  * SPDX-License-Identifier: LGPL-2.0-or-later
0004  */
0005 
0006 #ifndef JSONLD_H
0007 #define JSONLD_H
0008 
0009 #include <QHash>
0010 #include <QString>
0011 
0012 #include <functional>
0013 #include <vector>
0014 
0015 namespace Rdf {
0016 class Quad;
0017 class Term;
0018 }
0019 
0020 class QByteArray;
0021 class QJsonObject;
0022 class QJsonValue;
0023 class QUrl;
0024 
0025 using JsonLdDocumentLoader = std::function<QByteArray(const QString&)>;
0026 using JsonLdCurieMap = QHash<QString, QString>;
0027 class JsonLdProperty;
0028 
0029 class JsonLdMetaType
0030 {
0031 public:
0032     void load(const QJsonObject &obj);
0033     void addProperty(JsonLdProperty &&property);
0034 
0035     QString name;
0036     QString qualifiedName;
0037     std::vector<JsonLdProperty> properties;
0038 };
0039 
0040 class JsonLdProperty {
0041 public:
0042     static JsonLdProperty fromJson(const QString &name, const QJsonValue &value);
0043 
0044     QString name;
0045     QString qualifiedName;
0046     QString type;
0047     QString prefix;
0048     JsonLdMetaType metaType;
0049 };
0050 
0051 class JsonLdContext
0052 {
0053 public:
0054     void load(const QByteArray &contextData, const JsonLdDocumentLoader &loader);
0055     void load(const QJsonObject &context);
0056     void resolve();
0057     JsonLdMetaType metaType(const QString &type) const;
0058 
0059     std::vector<JsonLdMetaType> metaTypes;
0060     JsonLdCurieMap curieMap;
0061     std::vector<JsonLdProperty> globalProperties;
0062 };
0063 
0064 
0065 /** JSON-LD to RDF conversion.
0066  *  @note This is far from a complete implementation of the full spec, this barely
0067  *  covers enough for the needs of DIVOC JWS verification.
0068  */
0069 class JsonLd
0070 {
0071 public:
0072     // we only support offline data, so a synchronous interface is fine
0073     void setDocumentLoader(const JsonLdDocumentLoader &loader);
0074 
0075     /** Convert JSON-LD object to RDF */
0076     std::vector<Rdf::Quad> toRdf(const QJsonObject &obj) const;
0077 
0078 private:
0079     Rdf::Term toRdfRecursive(const JsonLdContext &context, const QJsonObject &obj, std::vector<Rdf::Quad> &quads) const;
0080     void toRdfRecursive(const JsonLdContext &context, const JsonLdMetaType &mt, const Rdf::Term &id, const QJsonObject &obj, std::vector<Rdf::Quad> &quads) const;
0081     Rdf::Term idForObject(const QJsonObject &obj) const;
0082 
0083     JsonLdDocumentLoader m_documentLoader;
0084     mutable int m_blankNodeCounter = 0;
0085 };
0086 
0087 #endif // JSONLD_H