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12.3.1 AcceptEventAction


   See AcceptEventAction (from CompleteActions ) on page 245.

*Attributes

   No additional attributes

*Associations

   No additional associations

*Constraints

   No additional constraints

*Semantics

   If an AcceptEventAction has no incoming edges, then the action starts when the containing activity or structured node does, whichever most immediately contains the action. In addition, an AcceptEventAction with no incoming edges remains enabled after it accepts an event. It does not terminate after accepting an event and outputting a value, but continues to wait for other events. This semantic is an exception to the normal execution rules in Activities. An AcceptEventAction with no incoming edges and contained by a structured node is terminated when its container is terminated.

*Notation

   See AcceptEventAction (from CompleteActions ) on page 245.

*Examples

    Figure 12.25 is an example of the acceptance of a signal indicating the cancellation of an order. The acceptance of the signal causes an invocation of a cancellation behavior. This action is enabled on entry to the activity containing it, therefore no input arrow is shown.


   Figure 12.25 - Accept signal, top level in scope.

   In Figure 12.26 , a request payment signal is sent after an order is processed. The activity then waits to receive a payment confirmed signal. Acceptance of the payment confirmed signal is enabled only after the request for payment is sent; no confirmation is accepted until then. When the confirmation is received, the order is shipped.


   Figure 12.26 - Accept signal, explicit enable

   In Figure 12.27 , the end-of-month accept time event action generates an output at the end of the month. Since there are no incoming edges to the time event action, it is enabled as long as its containing activity or structured node is. It will generate an output at the end of every month.


   Figure 12.27 - Repetitive time event

   See AcceptEventAction (from CompleteActions ) on page 245.

*Changes from previous UML

   See AcceptEventAction (from CompleteActions ) on page 245.