Activity Diagrams
In UML, activity diagrams are used to model the behavior of operations, classes, or use cases. This chapter describes how activity diagrams are used to model the behavior of operations.
Activity diagrams describe the interaction between activities and objects.
Activities
There are several types of activities. For the implementation of operations, the Bridge supports two kinds of activities:
| Activity Type | Description | Documentation Link |
|---|---|---|
| Action | Actions are used to describe actions applied to objects or the environment. They may contain so-called action scripts, or can be stereotyped signaling a special kind of an action. For instance, <<SQLAdapter>> actions apply actions to SQL databases. | Actions |
| Call Behavior Action | Call Behavior Actions give a link to other activities. Therefore, it is possible to decompose the behavioral logic into smaller units of activities. | Call Behavior Actions |
| Call Operation Action | Call Operation Actions call operations of classes. | Calling Class Operations |
Objects
Besides activities, there are object nodes, which represent object flow through activities and change their state by doing so. Object nodes may be input and output of actions, or input and output of activity diagrams.
Object nodes may originate outside of the context of an activity diagram – in other words, they are input to the activity diagram.
On the other side, activity diagrams may produce object nodes that are used as output. Output object nodes can be used as input of another action within the same context (the same activity diagram), or they can be passed on to an outside context, which can be a calling activity or a port type operation.