Nepomuk::Resource Class Reference

#include <Nepomuk/Resource>

Inheritance diagram for Nepomuk::Resource:

Public Member Functions
	Resource ()
	Resource (ResourceManager *manager)
	Resource (const Resource &)
	Resource (const QString &pathOrIdentifier, const QUrl &type=QUrl())
	Resource (const QString &pathOrIdentifier, const QUrl &type, ResourceManager *manager)
	Resource (const QString &pathOrIdentifier, const QString &type)
	Resource (const QUrl &uri, const QUrl &type=QUrl())
	Resource (const QUrl &uri, const QUrl &type, ResourceManager *manager)
	Resource (ResourceData *)
virtual	~Resource ()
void	addAltLabel (const QString &value)
void	addAnnotation (const Resource &value)
void	addIdentifier (const QString &value)
void	addIsRelated (const Resource &value)
void	addIsTopicOf (const Resource &value)
void	addProperty (const QUrl &uri, const Variant &value)
void	addSymbol (const QString &value)
void	addTag (const Tag &value)
void	addTopic (const Resource &value)
void	addType (const QUrl &type)
QHash< QString, Variant >	allProperties () const
QStringList	altLabels () const
QList< Resource >	annotationOf () const
QList< Resource >	annotations () const
QString	className () const
QString	description () const
bool	exists () const
QString	genericDescription () const
QString	genericIcon () const
QString	genericLabel () const
bool	hasProperty (const QUrl &uri) const
bool	hasProperty (const Types::Property &p, const Variant &v) const
bool	hasProperty (const QString &uri) const
bool	hasType (const QUrl &typeUri) const
QStringList	identifiers () const
void	increaseUsageCount ()
bool	isFile () const
QList< Resource >	isRelatedOf () const
QList< Resource >	isRelateds () const
QList< Resource >	isTopicOfs () const
bool	isValid () const
QString	label () const
ResourceManager *	manager () const
bool	operator!= (const Resource &) const
Resource &	operator= (const Resource &other)
Resource &	operator= (const QUrl &uri)
bool	operator== (const Resource &) const
Thing	pimoThing ()
QHash< QUrl, Variant >	properties () const
Variant	property (const QUrl &uri) const
Variant	property (const QString &uri) const
quint32	rating () const
void	remove ()
void	removeProperty (const QUrl &uri)
void	removeProperty (const QUrl &uri, const Variant &value)
void	removeProperty (const QString &uri)
QUrl	resourceType () const
QUrl	resourceUri () const
void	setAltLabels (const QStringList &value)
void	setAnnotations (const QList< Resource > &value)
void	setDescription (const QString &value)
void	setIdentifiers (const QStringList &value)
void	setIsRelateds (const QList< Resource > &value)
void	setIsTopicOfs (const QList< Resource > &value)
void	setLabel (const QString &value)
void	setProperty (const QUrl &uri, const Variant &value)
void	setProperty (const QString &uri, const Variant &value)
void	setRating (const quint32 &value)
void	setSymbols (const QStringList &value)
void	setTags (const QList< Tag > &value)
void	setTopics (const QList< Resource > &value)
void	setTypes (const QList< QUrl > &types)
QStringList	symbols () const
QList< Tag >	tags () const
File	toFile () const
QList< Resource >	topics () const
QString	type () const
QList< QUrl >	types () const
QString	uri () const
int	usageCount () const

Static Public Member Functions
static QList< Resource >	allResources ()
static QString	altLabelUri ()
static QString	annotationUri ()
static QString	descriptionUri ()
static Resource	fromResourceUri (const KUrl &uri, const Nepomuk::Types::Class &type=Nepomuk::Types::Class(), ResourceManager *manager=0)
static QString	identifierUri ()
static QString	isRelatedUri ()
static QString	isTopicOfUri ()
static QString	labelUri ()
static QString	ratingUri ()
static QString	symbolUri ()
static QString	tagUri ()
static QString	topicUri ()

Detailed Description

Resource is the central object type in Nepomuk.

It represents a piece of information of any kind.

Resources are identified by their unique URI (which correlates directly with the URI in the local NEPOMUK RDF storage.

Resource objects with the same URI share their data.

All methods in Resource are thread-safe.

See Using Nepomuk for details on how to use Resource.

See also

ResourceManager

Special case: file URLs

file:/ URLs are handled as a special case in Nepomuk. Starting with KDE 4.4 they are no longer used to identify the Nepomuk resource but only stored as nie:url property. All resources have nepomuk:/res/ <UUID> URIs. The Resource constructors handle this automatically. Thus, one can still use file URLs to construct the objects. But be aware of the following example:

KUrl fileUrl("file:///home/foobar/example.txt");
Nepomuk::Resource fileRes(fileUrl);
QUrl fileResUri = fileRes.resourceUri();

Here fileUrl and fileResUri are NOT equal. The latter is the resource URI of the form nepomuk:/res/ <UUID>.

Author

Sebastian Trueg trueg.nosp@m.@kde.nosp@m..org

Definition at line 94 of file resource.h.

Constructor & Destructor Documentation

Nepomuk::Resource::Resource

(

)

Creates an empty invalid Resource.

An invalid resource will become valid (i.e. get a new random URI) once setProperty is called.

Nepomuk::Resource::Resource

(

ResourceManager *

manager

)

Creates an empty invalid Resource.

An invalid resource will become valid (i.e. get a new random URI) once setProperty is called.

Parameters

manager

The resource manager to use. This allows to mix resources from different managers and, thus, different models.

Since

4.3

Nepomuk::Resource::Resource

(

const Resource &

)

Copy constructor.

Nepomuk::Resource::Resource	(	const QString &	pathOrIdentifier,
		const QUrl &	type = QUrl()
	)

Creates a new Resource object.

The actual resource data is loaded on demand. Thus, it is possible to work with Resources as if they were in memory all the time.

Parameters

pathOrIdentifier

The path to a file or an arbitrary identifier of the resource. The following cases are handled: A local file path is converted to a local file URL A URI which already exist in Nepomuk results in loading of that particular resource. A string which already exists as the nao:identifier of a resource results in loading of that particular resource. Any other string is used as nao:identifier for a new resource. This resource can later be loaded again by using the same identifier with this constructor.

type

The URI identifying the type of the resource. If it is empty Resource falls back to http://www.w3.org/2000/01/rdf-schema#Resource or in case the resource already exists the type will be read from the store.

Example:

The best way to understand the path or identifier system is through tags. There are two ways to create a resource that represents an existing tag. The first is the low level one: use the unique URI of the tag with the Resource(QUrl,QUrl) constructor. The second one is to use this constructor with the name of the tag as its identifier:

Resource myTag( "Nepomuk" );

This will result in Resource loading the tag with nao:identifier "Nepomuk".

Nepomuk::Resource::Resource	(	const QString &	pathOrIdentifier,
		const QUrl &	type,
		ResourceManager *	manager
	)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Parameters

manager

The resource manager to use. This allows to mix resources from different managers and, thus, different models.

Since

4.3

Nepomuk::Resource::Resource	(	const QString &	pathOrIdentifier,
		const QString &	type
	)

Deprecated:

use Resource( const QString&, const QUrl& )

Nepomuk::Resource::Resource	(	const QUrl &	uri,
		const QUrl &	type = QUrl()
	)

Creates a new Resource object.

Parameters

uri	The URI of the resource. If no resource with this URI exists, a new one is created. Using an empty QUrl will result in a new resource with a random URI being created on the first call to setProperty.

See the Special case: file URLs Special file URL handling.

Parameters

type	The URI identifying the type of the resource. If it is empty Resource falls back to http://www.w3.org/2000/01/rdf-schema#Resource or in case the resource already exists the type will be read from the store.

Nepomuk::Resource::Resource	(	const QUrl &	uri,
		const QUrl &	type,
		ResourceManager *	manager
	)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Parameters

manager

The resource manager to use. This allows to mix resources from different managers and, thus, different models.

Since

4.3

Nepomuk::Resource::Resource

(

ResourceData *

)

Constructor used internally.

virtual Nepomuk::Resource::~Resource ( )

virtual

Destructor.

Member Function Documentation

void Nepomuk::Resource::addAltLabel

(

const QString &

value

)

Add a value to property 'altLabel'.

void Nepomuk::Resource::addAnnotation

(

const Resource &

value

)

Add a value to property 'annotation'.

void Nepomuk::Resource::addIdentifier

(

const QString &

value

)

Add a value to property 'identifier'.

void Nepomuk::Resource::addIsRelated

(

const Resource &

value

)

Add a value to property 'isRelated'.

void Nepomuk::Resource::addIsTopicOf

(

const Resource &

value

)

Add a value to property 'isTopicOf'.

void Nepomuk::Resource::addProperty	(	const QUrl &	uri,
		const Variant &	value
	)

Add a property value to the existing values.

Parameters

uri	The URI identifying the property.
value	The value of the property (i.e. the object of the RDF triple(s))

Since

4.3

void Nepomuk::Resource::addSymbol

(

const QString &

value

)

Add a value to property 'Symbol'.

Each resource can have a symbol assigned. For now this is a simple string which can either be the path to an actual pixmap file or just the name of an icon as defined by the freedesktop.org standard.

void Nepomuk::Resource::addTag

(

const Tag &

value

)

Add a value to property 'Tag'.

Each Resource can be tagged with an arbitrary number of Tags. This allows a simple grouping of resources.

void Nepomuk::Resource::addTopic

(

const Resource &

value

)

Add a value to property 'Topic'.

void Nepomuk::Resource::addType

(

const QUrl &

type

)

Add a type to the list of types.

Since

4.2

QHash<QString, Variant> Nepomuk::Resource::allProperties

(

)

const

Deprecated:

Use properties()

static QList<Resource> Nepomuk::Resource::allResources ( )

static

Retrieve a list of all available Resource resources.

This list consists of all resource of type Resource that are stored in the local Nepomuk meta data storage and any changes made locally. Be aware that in some cases this list can get very big. Then it might be better to use libKNep directly.

See also

ResourceManager::allResources

Warning

This list will be very big. Usage of this method is discouraged. Use Query::QueryServiceClient in combination with an empty Query::Query instead.

QStringList Nepomuk::Resource::altLabels

(

)

const

Get property 'altLabel'.

static QString Nepomuk::Resource::altLabelUri ( )

static

Returns

The URI of the property 'altLabel'.

QList<Resource> Nepomuk::Resource::annotationOf

(

)

const

Get all resources that have this resource set as property 'annotation'.

See also

ResourceManager::allResourcesWithProperty

QList<Resource> Nepomuk::Resource::annotations

(

)

const

Get property 'annotation'.

static QString Nepomuk::Resource::annotationUri ( )

static

Returns

The URI of the property 'annotation'.

QString Nepomuk::Resource::className

(

)

const

The name of the class this Resource represents an object of.

The classname is derived from the type URI (see Resource::uri). For a translated user readable name of the resource see Ontology::typeName.

See also

type()

QString Nepomuk::Resource::description

(

)

const

Get property 'description'.

Everything can be annotated with a simple string comment.

static QString Nepomuk::Resource::descriptionUri ( )

static

Returns

The URI of the property 'description'.

bool Nepomuk::Resource::exists

(

)

const

Returns

true if this resource (i.e. the uri of this resource) exists in the local NEPOMUK RDF store.

static Resource Nepomuk::Resource::fromResourceUri ( const KUrl &  uri, const Nepomuk::Types::Class &  type = Nepomuk::Types::Class(), ResourceManager *  manager = 0  )

static

Allows to quickly load a resource from its resource URI without any additional checks.

This is mostly used for optimized code within Nepomuk.

In most situations the construtor Resource( QUrl, QUrl ) is better suited.

Since

4.5

QString Nepomuk::Resource::genericDescription

(

)

const

Tries very hard to find a suitable human-readable description of the resource.

This description is supposed to be longer than genericLabel() and includes such properties as nao:description, xesam:comment, rdfs:comment

Returns

A human readable description of the resource or an empty string if none could be found.

QString Nepomuk::Resource::genericIcon

(

)

const

Tries very hard to find an icon suitable for this resource.

Returns

An icon name to be used with KIcon or an empty string if none was found.

QString Nepomuk::Resource::genericLabel

(

)

const

Tries very hard to find a suitable human-readable label for this resource.

It looks for properties such as nao:prefLabel, rdfs:label, or nao:identifier, or even the fileName of File resources.

Returns

A human readable label or if all fails the URI of the resource.

bool Nepomuk::Resource::hasProperty

(

const QUrl &

uri

)

const

Check if property identified by uri is defined for this resource.

Parameters

uri	The URI identifying the property.

Returns

true if property uri has a value set.

bool Nepomuk::Resource::hasProperty	(	const Types::Property &	p,
		const Variant &	v
	)		const

Check if the resource has a property p with value v.

Since

4.5

bool Nepomuk::Resource::hasProperty

(

const QString &

uri

)

const

Deprecated:

use hasProperty( const QUrl& ) const

bool Nepomuk::Resource::hasType

(

const QUrl &

typeUri

)

const

Check if the resource is of a certain type.

The type hierarchy is checked including subclass relations.

QStringList Nepomuk::Resource::identifiers

(

)

const

Get property 'identifier'.

static QString Nepomuk::Resource::identifierUri ( )

static

Returns

The URI of the property 'identifier'.

void Nepomuk::Resource::increaseUsageCount

(

)

Increase the usage count of this resource and also update the last used date to the current date and time.

Since

4.5

bool Nepomuk::Resource::isFile

(

)

const

Returns

true if this resource represents a file. Use toFile() to retrieve the corresponding file resource which provides convinience methods to handle file resources.

Since

4.6

QList<Resource> Nepomuk::Resource::isRelatedOf

(

)

const

Get all resources that have this resource set as property 'isRelated'.

See also

ResourceManager::allResourcesWithProperty

QList<Resource> Nepomuk::Resource::isRelateds

(

)

const

Get property 'isRelated'.

static QString Nepomuk::Resource::isRelatedUri ( )

static

Returns

The URI of the property 'isRelated'.

QList<Resource> Nepomuk::Resource::isTopicOfs

(

)

const

Get property 'isTopicOf'.

static QString Nepomuk::Resource::isTopicOfUri ( )

static

Returns

The URI of the property 'isTopicOf'.

bool Nepomuk::Resource::isValid

(

)

const

Returns

true if this Resource object is valid, i.e. has a proper URI and type and can be synced with the local NEPOMUK RDF store.

An invalid resource will become valid (i.e. get a new random URI) once setProperty is called.

QString Nepomuk::Resource::label

(

)

const

Get property 'label'.

static QString Nepomuk::Resource::labelUri ( )

static

Returns

The URI of the property 'label'.

ResourceManager* Nepomuk::Resource::manager

(

)

const

The Resource manager that manages this resource.

Since

4.3

bool Nepomuk::Resource::operator!=

(

const Resource &

)

const

Operator to compare two Resource objects.

Since

4.4

Resource& Nepomuk::Resource::operator=

(

const Resource &

other

)

Makes this instance of Resource a copy of other.

Resource& Nepomuk::Resource::operator=

(

const QUrl &

uri

)

Same as operator=( Resource( uri ) )

bool Nepomuk::Resource::operator==

(

const Resource &

)

const

Operator to compare two Resource objects.

Thing Nepomuk::Resource::pimoThing

(

)

Get or create the PIMO thing that relates to this resource.

If this resource itself is a pimo:Thing, a reference to this is returned. If a pimo:Thing exists with has as occurrence this resource, the thing is returned. Otherwise a new thing is created.

Since

4.2

QHash<QUrl, Variant> Nepomuk::Resource::properties

(

)

const

Returns

A list of all defined properties

Variant Nepomuk::Resource::property

(

const QUrl &

uri

)

const

Retrieve the value of property uri.

If the property is not defined for this resource an invalid, empty Variant object is returned.

Parameters

uri	The URI identifying the property.

Variant Nepomuk::Resource::property

(

const QString &

uri

)

const

Deprecated:

use property( const QUrl& ) const

quint32 Nepomuk::Resource::rating

(

)

const

Get property 'Rating'.

static QString Nepomuk::Resource::ratingUri ( )

static

Returns

The URI of the property 'Rating'.

void Nepomuk::Resource::remove

(

)

Remove this resource completely.

CAUTION: After calling this method the resource will have been removed from the store without any trace.

void Nepomuk::Resource::removeProperty

(

const QUrl &

uri

)

Remove property uri from this resource object.

Parameters

uri	The URI identifying the property.

void Nepomuk::Resource::removeProperty	(	const QUrl &	uri,
		const Variant &	value
	)

Remove value from property uri of this resource object.

Parameters

uri	The URI identifying the property.
value	The value to remove

Since

4.3

void Nepomuk::Resource::removeProperty

(

const QString &

uri

)

Deprecated:

use removeProperty( const QUrl& )

QUrl Nepomuk::Resource::resourceType

(

)

const

The main type of the resource.

Nepomuk tries hard to make this the type furthest down the hierarchy. In case the resource has only one type, this is no problem. However, if the resource has multiple types from different type hierarchies, there is no guarantee which one will be used here.

See also

name(), hasType(), types()

QUrl Nepomuk::Resource::resourceUri

(

)

const

The URI of the resource, uniquely identifying it.

This URI in most cases is a virtual one which has been created from a generic base namespace and some identifier.

The most important thing to remember is that the URI of for example a file does not necessarily have a relation to its local path.

Returns

The resource URI of the resource or an empty url if the resource does not exist() yet.

See also

getIdentifiers()

void Nepomuk::Resource::setAltLabels

(

const QStringList &

value

)

Set property 'altLabel'.

void Nepomuk::Resource::setAnnotations

(

const QList< Resource > &

value

)

Set property 'annotation'.

void Nepomuk::Resource::setDescription

(

const QString &

value

)

Set property 'description'.

Everything can be annotated with a simple string comment.

void Nepomuk::Resource::setIdentifiers

(

const QStringList &

value

)

Set property 'identifier'.

void Nepomuk::Resource::setIsRelateds

(

const QList< Resource > &

value

)

Set property 'isRelated'.

void Nepomuk::Resource::setIsTopicOfs

(

const QList< Resource > &

value

)

Set property 'isTopicOf'.

void Nepomuk::Resource::setLabel

(

const QString &

value

)

Set property 'label'.

void Nepomuk::Resource::setProperty	(	const QUrl &	uri,
		const Variant &	value
	)

Set a property of the resource.

Parameters

uri	The URI identifying the property.
value	The value of the property (i.e. the object of the RDF triple(s))

void Nepomuk::Resource::setProperty	(	const QString &	uri,
		const Variant &	value
	)

Deprecated:

use setProperty( const QUrl& )

void Nepomuk::Resource::setRating

(

const quint32 &

value

)

Set property 'Rating'.

void Nepomuk::Resource::setSymbols

(

const QStringList &

value

)

Set property 'Symbol'.

Each resource can have a symbol assigned. For now this is a simple string which can either be the path to an actual pixmap file or just the name of an icon as defined by the freedesktop.org standard.

void Nepomuk::Resource::setTags

(

const QList< Tag > &

value

)

Set property 'Tag'.

Each Resource can be tagged with an arbitrary number of Tags. This allows a simple grouping of resources.

void Nepomuk::Resource::setTopics

(

const QList< Resource > &

value

)

Set property 'Topic'.

void Nepomuk::Resource::setTypes

(

const QList< QUrl > &

types

)

Set the types of the resource.

Previous types will be overwritten.

Since

4.2

QStringList Nepomuk::Resource::symbols

(

)

const

Get property 'Symbol'.

Each resource can have a symbol assigned. For now this is a simple string which can either be the path to an actual pixmap file or just the name of an icon as defined by the freedesktop.org standard.

static QString Nepomuk::Resource::symbolUri ( )

static

Returns

The URI of the property 'Symbol'.

QList<Tag> Nepomuk::Resource::tags

(

)

const

Get property 'Tag'.

Each Resource can be tagged with an arbitrary number of Tags. This allows a simple grouping of resources.

static QString Nepomuk::Resource::tagUri ( )

static

Returns

The URI of the property 'Tag'.

File Nepomuk::Resource::toFile

(

)

const

Convert this resource into a File resource to have access to the convinience methods provided by the File class.

Since

4.6

QList<Resource> Nepomuk::Resource::topics

(

)

const

Get property 'Topic'.

static QString Nepomuk::Resource::topicUri ( )

static

Returns

The URI of the property 'Topic'.

QString Nepomuk::Resource::type

(

)

const

The main type of the resource.

Nepomuk tries hard to make this the type furthest down the hierarchy. In case the resource has only one type, this is no problem. However, if the resource has multiple types from different type hierarchies, there is no guarantee which one will be used here.

For historical reasons the method does return a URI as QString instead of QUrl. The value equals resourceType().toString().

See also

name(), hasType(), types()

Deprecated:

use resourceType instead

QList<QUrl> Nepomuk::Resource::types

(

)

const

Returns

The list of all stored types for this resource. This may also include types that lie in the same hierachy.

See also

type(), hasType()

QString Nepomuk::Resource::uri

(

)

const

The URI of the resource, uniquely identifying it.

This URI in most cases is a virtual one which has been created from a generic base namespace and some identifier.

The most important thing to remember is that the URI of for example a file does not necessarily have a relation to its local path. (Although Nepomuk tries to keep the URI of file resources in sync with the file URL for convenience.)

For historical reasons the method does return a URI as QString instead of QUrl. The value equals resourceUri().toString().

See also

resourceUri(), getIdentifiers()

Deprecated:

use resourceUri() instead

int Nepomuk::Resource::usageCount

(

)

const

Returns

The usage count stored for this resource.

See also

increaseUsageCount()

Since

4.5

---

The documentation for this class was generated from the following file:

• resource.h