UML Weekend Crash Course™ - To Parent Directory

170
Saturday Afternoon
A message or stimulus is usually a call, a signal, or a response. A message is represented
by an arrow. The type of arrow visually describes the type of message. The solid line and
solid arrowhead style represent a message that requires a response. The dashed arrows are
the responses. (I cover more arrow types later in this session.) The messages are placed horizontally
onto the timelines in relative vertical position to one another to represent the
order in which they happen. This arrangement allows you to read the diagram from beginning
to end by reading the messages from top to bottom.
Bill : Customer
Bill's Order : Order
: Inventory
1
2
3
1: Order()
2: return order
3 [for each product] : additem(product)
4: productAvailable(product)
5: return yes
6
7
8
4
6 [product available=yes] : addProduct(product)
9
5
7: return done
10
8: return done
Figure 16-2 Elements of the Sequence diagram notation
The reference numbers on Figure 16-2 denote these items:
1. Object lifeline
2. Message/Stimulus
3. Iteration
4. Self-reference
There is more to this scenario
than shown here.