Overview of $ModelTypes
An EDG Enumeration is a lightweight form of reference data or datatype, similar to a list of codes or labels. Each enumeration is a (sub-) class that has a finite (and typically small and closed) set of value instances, for example: days of the week, colors of the rainbow, states of an entity or process, or levels of a rating/ranking scale. The values can have properties such as text labels, numeric codes, ordinal values, etc. Enumerations can serve in numerous modeling contexts, such as providing pick-lists or code-lists.
Users can create enumeration collections that contain:
EDG Product Enumerations
EDG provides dozens of predefined enumeration classes, whose values can be customized per installation. Although these classes are predefined in EDG, their values are not preloaded. To load them, create or select one or more Enumeration collections and then in each one import selected EDG Product Enumerations and their values as described in: utilities > Import... > Enumerations Batch Importer . Once imported, the product values can be customized per installation.
EDG Product Enumerations should be maintained as singletons, with unique (non-duplicated) imports and value sets.
Property Value Selectors
A Property Value Selector (PVS) provides another way to specify a set of values. Using one property of a particular class, a PVS all of the corresponding (unique) values from all instances in a particular graph. (This is analogous—in relational database terms—to the set of unique (row) values from one column of a particular table.) A PVS thus determines its values indirectly: from instances of a class based on the designated property.
A typical use of a PVS would be to express permitted values on an imported data element. For example the permitted values for a country code might be the ISO 2 character or 3 character country codes from a reference dataset. In this case, the PVS's graph of instances would be a reference dataset and the PVS's class would be the dataset's main entity class.
The Create dialog box asks for the $ModelType's Label (name), an optional Description, and either a Schema or an Ontology that will define the class of enumeration instances (values). The default namespace will be used to construct URIs (unique identifiers) for the classes, properties and other resources in the ontology.
Create New $ModelType
This creates a new $ModelType with yourself as the manager.
If using Search the EDG with Lucene indexing (the default option), an option exists on create to add this collection to the index. This is the same as selecting it in Search the EDG configurations with the default property selectors.