# class OntologyManager

###

Module | nepomuk
Namespace | Nepomuk
Class | OntologyManager
Inherits |

The OntologyManager is the central ontology cache handler. It is modeled as a singleton and its instance can be accessed through OntologyManager.instance.

Deprecated Ontologies should be handled via the classes in Nepomuk.Types.

### methods

- OntologyManager ( )

  returns ctor
  Not implemented

- getOntology (uri)

  returns Nepomuk.Ontology

  Argument | Type | Default
  --- | --- | ---
  uri | QUrl |

  Attempt to load the ontology referenced by uri. If the manager already has the ontology in the cache it is simply returned. Otherwise the manager tries to load the ontology from one of the configured OntologyLoader instances.

  Returns The requested ontology or 0 in case it could not be found, i.e. none of the OntologyLoader instances could provide the RDF statements making up the ontology.

- instance ( )

  returns Nepomuk.OntologyManager
  static

- setOntologyLoader (loader)

  returns Nothing

  Argument | Type | Default
  --- | --- | ---
  loader | OntologyLoader |

  Set an OntologyLoader to be used to retrieve the RDF statements that make up an ontology.

  By default Nepomuk uses a combination of the NepomukOntologyLoader and DesktopOntologyLoader where the NepomukOntologyLoader is the preferred one, i.e. only if it is not able to load the ontology DesktopOntologyLoader is used as a fallback.

  If an OntologyLoader is set no fallback loader will be used. Thus, to force one of the default loaders (for example the DesktopOntologyLoader) just do:

      OntologyManager.instance()->setOntologyLoader( new DesktopOntologyLoader() );

  OntologyManager will take over ownership of loader.

  Overwriting the loader will delete any loader previously set via setOntologyLoader.