State Elements

State elements define the structure and behavior of your state machine.

Available Elements

State

The <state> element represents a standard state in the state machine. It can be simple or compound, containing other states.

Parallel

The <parallel> element enables concurrent execution of multiple states, useful for independent processes.

Final

The <final> element represents a terminal state, marking the completion of a region or machine.

Common Use Cases

Basic State Machine

<state id="process">
<state id="start">
  <transition target="working" />
</state>
 
<state id="working">
  <transition target="done" />
</state>
 
<final id="done" />
</state>

Parallel Processing

<parallel id="dataHandling">
<state id="validation">
  <transition event="valid" target="validated" />
</state>
 
<state id="transformation">
  <transition event="transformed" target="complete" />
</state>
</parallel>

Process Completion

<final id="complete">
<donedata>
  <content>
    {({state}) => ({
      result: state.output,
      timestamp: new Date()
    })}
  </content>
</donedata>
</final>

Best Practices

1. State Design

   • Use meaningful state names
   • Keep states focused
   • Document state purpose
   • Consider state hierarchy

2. Parallel Processing

   • Keep states independent
   • Handle shared resources
   • Manage concurrency
   • Coordinate completion

3. Final States

   • Include completion data
   • Clean up resources
   • Log completion
   • Handle errors

4. State Management

   • Initialize properly
   • Track state changes
   • Handle transitions
   • Maintain consistency

Key Concepts

1. State Hierarchy

   • Simple states
   • Compound states
   • Parallel states
   • Final states

2. State Lifecycle

   • Entry actions
   • Exit actions
   • Transitions
   • Completion

3. Data Management

   • State data
   • Shared data
   • Data persistence
   • Data cleanup

4. Error Handling

   • Error states
   • Recovery paths
   • Resource cleanup
   • Error reporting

See Also

• Control Flow Elements
• Action Elements
• SCXML Elements
• Best Practices