Transition

A Transition in a State Machine Diagram represents a change from one state to another. It shows how an object moves between states in response to events, under certain conditions, and with specified actions.

With Transitions in Modeldraw's State Machine Diagram, you can:

• Show how an object changes from one state to another

• Specify events that trigger state changes

• Define conditions (guards) that must be true for a transition to occur

• Indicate actions that are performed during the state change

• Illustrate the flow of control in your state machine

• Represent complex behaviors and decision points in your system

A Transition

Understanding Transition

A Transition in Modeldraw's State Machine Diagram tool is represented by an arrow connecting two states. Key points to understand about Transitions include:

• Transitions connect a source state to a target state.

• An Event is the trigger that causes the transition to occur.

• A Guard is a condition that must be true for the transition to take place.

• An Action is behavior that is executed when the transition occurs.

• A self-transition is a transition that starts and ends on the same state.

• Transitions are labeled with the format "event [guard] / action".

Creating a Transition

To create a Transition in Modeldraw's State Machine Diagram:

1. Select the Transition tool from the toolbox.

2. Click on the source state (the state where the transition begins).

3. Move your mouse to the target state (the state where the transition ends).

4. Click on the target state to complete the transition.

5. To add details to the transition, double-click on the transition arrow. In the properties dialog that appears, you can specify:

   • Event

   • Guard

   • Action

Remember that transitions should reflect real-world events and conditions that cause your system to change states.

Creating a Self-Transition

A self-transition in a State Machine Diagram represents an action that occurs within a state but does not cause a change to a different state. It's useful for modeling internal actions or events that a state can handle without transitioning to another state.

To create a self-transition in Modeldraw's State Machine Diagram:

1. Select the Transition tool from the toolbox.

2. Click on the State where you want to add the self-transition.

3. Click again on the same State.

4. A curved arrow should appear, starting and ending on the same State.

An example of a Self-Transition