Class Hierarchy Panel

The Class Hierarchy Panel displays a hierarchy of classes starting with a selected root class. The hierarchical relationship between those classes is rdfs:subClassOf. You can re-arrange classes in the hierarchy by dragging and dropping.

In TopBraid, every asset is a member/instance of at least one class. Properties are associated with classes and a default view of the asset is determined by the classes it belongs to. Alternative views can be defined by node shapes that are not classes themselves but target members of a class.

You can also set the root to any class of your choice via Manage > Root of Class Hierarchy Panel. This might be desired, for example, if your ontology specializes another ontology, and you don’t want to show the ancestor classes of your custom classes.

Toolbar Features

• Quick Search lets you look up classes displayed in the tree. The lookup is limited only to classes that are children of the currently selected root. When you are in the mode where it displays IDs instead of labels, this turns into a qname auto-complete.

• Switch to full text search will switch from autocomplete lookup based on the label to the full text search across all string properties.

• Create Class is only visible in Ontology asset collection types, as the other collection types are not permitted to contain classes and properties. It opens the Create Class Dialog allowing you to create a new class as subclass of the selected class (or the root class). Alternatively, right click on any class and select Create subclass of ….

When you create new classes, TopBraid will display a dialog box where you enter the name of your new class and optionally edit the URI generated by TopBraid as an internal ID for the class.

By default, TopBraid will automatically generate a URI to uniquely identify the resource by combining the default namespace specified for the ontology on its creation (the default being http://example.org/ontologies/<asset collection name>#) with a user-entered label for the resource, with any characters that would cause problems in a URI being converted. For example, the URI generated for a class with the label “Nonprofit Organization” might be http://example.org/ontologies/my_ontology#NonprofitOrganization. If the generated URI is non-unique, EDG will give you a message that the asset already exists.

Note

Every new class will also be typed as a SHACL Node Shape. If you have started by loading into TopBraid ontologies in RDFS/OWL, use Transform > Convert OWL Axioms to SHACL Constraints to generate SHACL Shapes.

Settings

• Switch the root class between owl:Thing and rdfs:Resource is visible if no root class has been configured using Manage > Root of Class Hierarchy Panel. By default, the root class in the Classes panel is set to Thing (owl:Thing), which is commonly used as root of domain-specific ontologies. However, many other classes can be found as roots of rdfs:Resource, and these are often considered “system classes” such as the definitions of SHACL, RDFS and the classes that drive EDG itself.

• Also show classes marked as hidden is off by default but will also show classes that were marked hidden using dash:hidden.

• Display IDs instead of labels switches between human-friendly labels and system-friendly qnames.

See Also

• Class List Panel

• Create Class Dialog

• Instances Panel

• Manage > Allow filtering Class Hierarchy to locally defined Classes

• Manage > Root of Class Hierarchy Panel

• Node Shapes Panel

• Property Groups Panel

• RDF/OWL Properties Panel

Further Reading on Ontologies

• Working with Ontologies

Further Reading on TopBraid

• Introduction to EDG