xR984

R984 / 1:1c

Delegated Create Action signals creation with exactly one Monomorphic Event

Monomorphic Event signals creation for zero or one Delegated Create Action

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An Event must be delivered to the newly created instance to put it in an initial State triggering that state's Activity.

The initial event must be monomorphic. Let's consider why this must be so. Imagine that you want to create an instance somewhere deep within a Lineage in a set of Generalizations. Polymorphism allows you to target an event at an instance of an unknown subclass. To perform the creation, however, you need to specify every class in the Lineage providing all initial attribute values which means that you always know the target Class. So while the MX domain is capable of delivering a polymorphic event to a newly created instance, polymorphism adds no benefit to the creation process itself.

Any given Monomorphic Event may or may not be used for the purpose of delegated creation.

Formalization

Delegated Create Action.(Initial event, Target class, Domain) -> Monomorphic Event.(Name, State model, Domain)

Constraints

Target class {R984c}

While a Monomorphic Event can be associated with either an Assigner or a Lifecycle, a Delegated Creation may only specify one associated with a Lifecycle. By ensuring that the referenced State model attribute is a Class name (as implied in the naming of the corresponding referential attribute, we enforce this constraint.