KDE 4.2 API Reference soprano
Soprano::Node Class Reference
#include <Soprano/Node>
Detailed Description
A Node represents one RDF resource.Nodes are the cornerstone of RDF data in Soprano. Four Nodes form one Statement and a Model is essentially a set of Statements.
A Node can have one of four types: EmptyNode, ResourceNode, LiteralNode, and BlankNode. Resource nodes are identified through their URI (uri()), literal nodes have a LiteralValue (literal()) and an optional language string (language()), and blank nodes have a string identifier.
Empty nodes can be used as wildcards in methods such as Model::listStatements.
- Warning:
- Be aware that string literals in Soprano always have type xsd:string. There is no direct support for rdfs:Literal. Backend implementations should honour this restriction.
Definition at line 55 of file node.h.
Public Types | |
| enum | Type { EmptyNode = 0, ResourceNode = 1, LiteralNode = 2, BlankNode = 3 } |
Public Member Functions | |
Literal nodes | |
| QUrl | dataType () const |
| QString | language () const |
| LiteralValue | literal () const |
Blank nodes | |
| QString | identifier () const |
Type information | |
| bool | isBlank () const |
| bool | isEmpty () const |
| bool | isLiteral () const |
| bool | isResource () const |
| bool | isValid () const |
| Type | type () const |
Operators | |
| bool | matches (const Node &other) const |
| bool | operator!= (const Node &other) const |
| Node & | operator= (const LiteralValue &literal) |
| Node & | operator= (const QUrl &resource) |
| Node & | operator= (const Node &other) |
| bool | operator== (const LiteralValue &other) const |
| bool | operator== (const QUrl &other) const |
| bool | operator== (const Node &other) const |
Constructors | |
| Node (const Node &other) | |
| Node (const LiteralValue &value, const QString &language=QString()) | |
| Node (const QString &id) | |
| Node (const QUrl &uri) | |
| Node () | |
| ~Node () | |
| QString | toString () const |
Resource nodes | |
| QUrl | uri () const |
Static Public Member Functions | |
| static Node | createBlankNode (const QString &id) |
| static Node | createEmptyNode () |
| static Node | createLiteralNode (const LiteralValue &value, const QString &language) |
| static Node | createResourceNode (const QUrl &uri) |
Member Enumeration Documentation
| enum Soprano::Node::Type |
- Enumerator:
-
EmptyNode An empty node, can be used as a placeholder in commands like Model::listStatements. ResourceNode A resource node has a URI which can be accessed via uri(). LiteralNode A literal node has a literal value and an optional language. BlankNode blank node has an identifier string
Constructor & Destructor Documentation
| Soprano::Node::Node | ( | ) |
| Soprano::Node::Node | ( | const QUrl & | uri | ) |
Creates a resource node.
- Parameters:
-
uri The URI of the node. If empty the type will be ignored and an empty node will be created.
- See also:
- createResourceNode()
| Soprano::Node::Node | ( | const QString & | id | ) | [explicit] |
| Soprano::Node::Node | ( | const LiteralValue & | value, | |
| const QString & | language = QString() | |||
| ) |
Creates a literal node.
- Parameters:
-
value The value of a node. If empty the node will become an empty node. language The language of the literal value.
- See also:
- createLiteralNode()
| Soprano::Node::Node | ( | const Node & | other | ) |
| Soprano::Node::~Node | ( | ) |
Member Function Documentation
Convenience method to create a blank node.
Using this method instead of the constructor may result in better readable code.
If you need to create a new blank node which is not used in the model yet and, thus, has a unique identifier see Model::createBlankNode().
- Parameters:
-
id An identifier for the blank node.
- Returns:
- A blank node or an empty Node if the specified identifier was empty.
| static Node Soprano::Node::createEmptyNode | ( | ) | [static] |
Convenience method to create an empty node.
Using this method instead of the default constructor may result in better readable code.
- Returns:
- An empty Node.
| static Node Soprano::Node::createLiteralNode | ( | const LiteralValue & | value, | |
| const QString & | language | |||
| ) | [static] |
Convenience method to create a literal node.
Using this method instead of the constructor may result in better readable code.
- Parameters:
-
value The value of a node. If empty the node will become an empty node. language The language of the literal value.
- Returns:
- A literal node or an empty node if the specified value was empty.
Convenience method to create a resource node.
Using this method instead of the constructor may result in better readable code.
- Parameters:
-
uri The URI of the node. If empty the type will be ignored and an empty node will be created.
| QUrl Soprano::Node::dataType | ( | ) | const |
- Returns:
- The datatype URI of a literal node, i.e.
the XML schema type or an empty value if the node is not a literal.
- See also:
- LiteralValue::dataTypeUri
| QString Soprano::Node::identifier | ( | ) | const |
Retrieve a blank node's identifier.
- Returns:
- The node's identifier if it is a blank node, a null string otherwise.
| bool Soprano::Node::isBlank | ( | ) | const |
| bool Soprano::Node::isEmpty | ( | ) | const |
| bool Soprano::Node::isLiteral | ( | ) | const |
| bool Soprano::Node::isResource | ( | ) | const |
| bool Soprano::Node::isValid | ( | ) | const |
| QString Soprano::Node::language | ( | ) | const |
Each literal value can have an associated language, thus each property can be stored for different languages.
An empty language refers to the default language.
- Returns:
- A string representing the language of the literal value or an empty string if the node is not a literal.
| LiteralValue Soprano::Node::literal | ( | ) | const |
| bool Soprano::Node::matches | ( | const Node & | other | ) | const |
Match this node against other.
The only difference to operator== is that empty nodes are matched as wildcards, i.e. they match any other node.
- Returns:
- true if this node matches other, false if not.
| bool Soprano::Node::operator!= | ( | const Node & | other | ) | const |
| Node& Soprano::Node::operator= | ( | const LiteralValue & | literal | ) |
Assigns resource to this node and makes it a ResourceNode.
| bool Soprano::Node::operator== | ( | const LiteralValue & | other | ) | const |
| bool Soprano::Node::operator== | ( | const QUrl & | other | ) | const |
| bool Soprano::Node::operator== | ( | const Node & | other | ) | const |
| QString Soprano::Node::toString | ( | ) | const |
Converts the Node to a string.
- Returns:
- A String representation of the Node.
- See also:
- LiteralValue::toString(), QUrl::toString()
| QUrl Soprano::Node::uri | ( | ) | const |
The documentation for this class was generated from the following file:
