1/*
2 This file is part of the syndication library
3 SPDX-FileCopyrightText: 2006 Frank Osterfeld <osterfeld@kde.org>
4
5 SPDX-License-Identifier: LGPL-2.0-or-later
6*/
7
8#ifndef SYNDICATION_RDF_NODE_H
9#define SYNDICATION_RDF_NODE_H
10
11#include "../syndication_export.h"
12
13#include <QSharedPointer>
14#include <QString>
15
16namespace Syndication
17{
18namespace RDF
19{
20class Model;
21class Node;
22class NodeVisitor;
23//@cond PRIVATE
24typedef QSharedPointer<Node> NodePtr;
25//@endcond
26
27/*!
28 * an RDF node, abstract baseclass for all RDF node types, like resources and
29 * literals
30 */
31class Node
32{
33public:
34 /*!
35 * destructor
36 */
37 virtual ~Node();
38
39 /*!
40 * Used by visitors for double dispatch. See NodeVisitor
41 * for more information.
42 * \a visitor the visitor calling the method
43 * \a ptr a shared pointer object for this node
44 */
45 virtual void accept(NodeVisitor *visitor, NodePtr ptr);
46
47 /*!
48 * returns a copy of the object. Must be implemented
49 * by subclasses to return a copy using the concrete
50 * type
51 */
52 virtual Node *clone() const = 0;
53
54 /*!
55 * returns whether this node is a null node
56 */
57 virtual bool isNull() const = 0;
58
59 /*!
60 * returns whether this node is a resource
61 */
62 virtual bool isResource() const = 0;
63
64 /*!
65 * returns whether this node is a property
66 */
67 virtual bool isProperty() const = 0;
68
69 /*!
70 * returns whether this node is a literal
71 */
72 virtual bool isLiteral() const = 0;
73
74 /*!
75 * returns whether this node is an RDF sequence
76 */
77 virtual bool isSequence() const = 0;
78
79 /*!
80 * returns whether this node is an anonymous resource
81 */
82 virtual bool isAnon() const = 0;
83
84 /*!
85 * the identifier of this node. the ID is unique per model
86 * and set by the associated model at creation time.
87 */
88 virtual unsigned int id() const = 0;
89
90 /*!
91 * returns a textual representation of the node.
92 * This is the literal string for literals, and a null string for other
93 * node types.
94 */
95 virtual QString text() const = 0;
96
97 /*!
98 * used in Model
99 * @internal
100 */
101 virtual void setModel(const Model &model) = 0;
102
103 /*!
104 * used in Model
105 * @internal
106 */
107 virtual void setId(unsigned int id) = 0;
108
109protected:
110 /*!
111 * used to generate unique IDs for node objects
112 */
113 static unsigned int idCounter;
114};
115
116} // namespace RDF
117} // namespace Syndication
118
119#endif // SYNDICATION_RDF_NODE_H
120

source code of syndication/src/rdf/node.h