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URIref Prefixes, Expand URIref Prefixes

This section describes the menu items: URIref Prefixes and Expand URIref Prefixes. Also see the related topic, Namespace Imports for RDF.

URIref Prefixes

Clicking the URIref Prefixes menu item pops up the URIref Prefixes dialog (screenshot below), in which all the namespaces declared for the active ontology are displayed. (The RDF, RDF Schema, and OWL namespaces are declared by default for new documents.) Via the dialog, you can (i) add namespaces to the ontology and bind these namespaces to customized prefixes, (ii) edit existing namespaces and prefixes, and (iii) delete a selected namespace.

To add a namespace or delete the selected namespace, use the Add and Delete buttons respectively. To edit a namespace or prefix, place the cursor in the appropriate field and edit using the keyboard.

Expand URIref Prefixes

After prefixes for namespaces have been assigned (see URIref Prefixes above), a resource can be defined or referenced in the RDF/XML serialization using either: (i) the prefix and local name, or (ii) the expanded URIref. To use the expanded URIref in the serialization, toggle the Expand URIref Prefixes command on. All URIrefs entered in RDF/OWL View after this, that have a prefix, will be serialized in the RDF/XML notation to the expanded URIref form if that prefix has been declared. If the prefix does not exist, then the URIref is serialized exactly as entered, that is, the prefix is read as the scheme part of a URI. The RDF/OWL View itself always displays the URIref as entered; URIrefs are not expanded in RDF/OWL View.

In actuality, what happens when this command is toggled on, is that every input is solely understood as a URI (absolute or relative) and is not understood as prefix-and-local-name. That is, prefixes that would have been expanded to a URI part when the option is activated are now simply used as the scheme part of the URI that is entered. Note that all relative URIs will be resolved against the document's global base URI.