Chapter 5 Building Dynamic Diagrams

States

A state represents a situation during the life of a classifier that is usually specified by conditions. It can also be defined as the situation of a classifier waiting for events. Stability and duration are two characteristics of a state.

A state can be created in the following diagrams:

Statechart Diagram

A state can be atomic or decomposed:

An atomic state does not contain sub-states, and has the following symbol:
A decomposed state contains sub-states, which are represented in a sub-diagram, and has the following symbol:

For more information on decomposed states, see "Decomposed states and sub-states".

Several states in a statechart diagram correspond to several situations during the life of the classifier.

Events and condition guards on output transitions define the stability of a state. Some actions can be associated with a state, especially when the object enters or exit the state. Some actions can also be performed when events occur inside the state; those actions are called internal transitions, they do not cause a change of state.

You cannot decompose shortcuts of states.

Drag a class, use case or component in a statechart diagram

The statechart diagram describes the behavior of a classifier. To highlight the relationship between a classifier and a state, you can define the context classifier of a state using the Classifier list in the state property sheet. This links the state to a use case, a component or a class.

You can also move, copy and paste, or drag a class, use case or component and drop it into a statechart diagram to automatically create a state associated with the element that has been moved.