PrF UG meta metaslot intro

Understanding Slot Metaclasses

Protege-Frames User's Guide
Metaclasses
Understanding Metaclasses
Example: Creating and Using a Metaclass
Looking at :STANDARD- CLASS
Creating a Metaclass
Creating a Class Using a Metaclass
Changing the Metaclass of a Class
Changing the Metaclass of Subclasses
Setting the Default Metaclass
Customizing the Class or Slot Editor
Understanding Slot Metaclasses
Creating a Slot Metaclass
Changing the Slot Metaclass of a Slot
Creating a Subslot Using a Slot Metaclass
Changing the Slot Metaclass of Subslots
Setting the Default Slot Metaclass
Glossary, Editing Help

Slot metaclasses are similar to metaclasses, except that they determine the properties of slots instead of classes. Therefore, a slot metaclass is a metaclass that can be used as a template to determine the way Protege-Frames constructs a slot. By creating a new slot metaclass, you can create a different template for selected slots and attach additional information to your slot at the class level.

Note that slot metaclasses appear at the Classes Tab as the :SLOT hierarchy. This is because every slot is an instance of a slot meta class. Slots are not values or subslots of a global slot. As with metaclasses, every subclass of a slot metaclass is also a slot metaclass.

Similar to metaclasses, slots are normally created using :STANDARD-SLOT, which provides the structure for slot attributes such as name, value type, etc. When you create a new slot metaclass, you will most often want to create it subordinate to :STANDARD-SLOT, so that any slots created using the slot metaclass will have the various properties defined by :STANDARD-SLOT.

"Class Browser, ":SLOT" selected