Interactions
Sequence Diagrams
A sequence diagram shows the exchange of messages between object lifelines.
Messages can be passed asynchronous (non-blocking) or synchronous (blocking).
Example: Checkout
Notes:
Solid arrowheads indicate synchronous message passing such as method calls.
Dashed arrows indicate return values.
Shaded rectangles indicate execution occurrences.
An interaction fragment is a boxed sequence of exchanges with a special constraint such as conditional or iterative execution.
Example: Marketplace
Notes:
Open arrows indicate asynchronous message passing.
Example: Event Notification
