Instance modeling: Instantiable definition types

Instantiable definition types allow abstract and concrete modeling within a type. In this context, any reference to instances, the instances themselves and any instantiable definitions, have no UML/OO Modeling implications.

For example, you can create a "Measure (DM2)" definition object called "Target Accuracy" and another, which is an instance of "Target Accuracy", called "High Target Accuracy". Other instances could be "Marine Target Accuracy", "Sniper Target Accuracy", and so on.

Definition "MyDef1"
{
INSTANTIABLE
PROPERTY "WWW" { EDIT HETEROGENEOUSLISTOF "Node" AND_SUBTYPES, "Package" SHOW_ON_INSTANCES }
PROPERTY "DEs" { EDIT LISTOF "Data Element" SHOW_ON_INSTANCES }
PROPERTY "DDs" { EDIT ONEOF "Data Domain" SHOW_ON_INSTANCES }
PROPERTY "XXX" { EDIT TEXT LENGTH 4 }
}

Instantiable definition type property level keyword indicating which properties are shown on abstract objects and which ones on concrete objects.

Definition level keyword indicating that objects of this type allow for creation of instances.

SHOW_ON_INSTANCES cannot be used on properties of non-instantiable definitions, or diagrams, or symbols.

Any deviation from the rules described in the “Declaration” chapter will be sanctioned by the parser and appropriate messages will be shown in a local report.

A Create Instance explorer context menu item is enabled only for objects of instantiable definition types.

After such an object has been created, you can create an instance: right‑click the object, and then click Create Instance.

When editing an instance (or concrete) object, the fact that it is an instance is indicated in the caption of the edit session.

An abstract object’s edit caption could be “Dictionary Object - Measure (DM2) - Target Accuracy”; where a concrete object, instance of “Target Accuracy” will be “Dictionary Object - Measure (DM2) - Instance Of Target Accuracy - High Target Accuracy”.

When editing objects of instantiable definition types, the following property depicting rules apply (through SHOW_ON_INSTANCES keyword usage):

	Keyword SHOW_ON_INSTANCE PRESENT	Keyword SHOW_ON_INSTANCE NOT PRESENT
Abstract object, non-reference property	Invisible	Visible
Abstract object, reference property	Visible	Visible
Concrete object (instance), non-reference property	Visible	Invisible
Concrete object (instance), reference property	Visible	Invisible

Editing behavior for references to objects of instantiable definition types from other objects of instantiable definition types

Properties of abstract objects referring to objects of instantiable definition types can contain only abstract objects; therefore, the respective choices lists contain only abstract objects.

Properties of concrete objects referring to objects of instantiable definition types can contain only concrete objects which are instances of the abstract objects referred to by their abstract counterparts; therefore, the respective choices lists contain only instances of those abstract objects.