Sequence Diagrams Getting the Message

Overview Sequence Diagrams are used to model the interactions among classes They are used at all stages of the development process Often they are used to show how Use cases are distributed assigned to various objects

Basic Elements

Database Update Sample

Message types

Message Descriptions Synchronous messages indicate that the flow is interrupted until the message is completed Return shows that control has returned to the calling object Asynchronous used for messages that are sent, but from which the active object doesn’t wait for a reply Flat makes no distinctions between synchronous and asynchronous

Message to Self

Creating objects

Adding States

Branching

Alternate Flows