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Download Sybase PowerDesigner Object Oriented Model User's Guide
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Chapter 6 Building a Sequence Diagram For more information on the create action, see section Creating a Create message in a sequence diagram. Destroy action The Destroy action allows you to show the destruction of an object in a sequence diagram. It means that the sender object destroys the receiver object. A large X is displayed on the lifeline of the receiver object. A message with a destroy action is the last message between a sender and a receiver. For more information on the destroy action, see section Creating a Destroy message in a sequence diagram. Self-Destroy action The Self-Destroy action allows you to show the self destruction of an object in a sequence diagram. It means that the sender object warns the receiver object that it is destroying itself. A large X is displayed on the lifeline of the sender object. A message with a self-destroy action is the last message between a sender and a receiver. It is only available if you select the Return control flow from the Control Flow dropdown listbox in the message property sheet. For more information on the self-destroy action, see section Creating a Self-Destroy message in a sequence diagram. Control flow The Control Flow dropdown listbox defines the different types of message control flow. A message has the following control flow values: Control flow Description Asynchronous Request in which the sending object does not wait for a result, it can do something else in parallel. Symbol No-wait semantics Procedure Call Call of a procedure. The sequence is complete before the next sequence resumes. The sender must wait for a response or the end of the activation Wait semantics Return Generally associated with a Procedure Call. The Return arrow may be omitted as it is implicit at the end of an activation Undefined No control flow defined By default, a message has an Undefined control flow. 239
