Action Elements

Action elements are used to perform operations and modify state within your workflow.

Available Elements

Assign

The <assign> element modifies data model values. Use it to update state, increment counters, or append to arrays.

Log

The <log> element outputs messages for debugging and tracing. Essential for development and troubleshooting.

Script

The <script> element executes JavaScript code. Useful for complex logic and computations.

Cancel

The <cancel> element cancels delayed events. Important for cleanup and workflow control.

Common Use Cases

1. State Management

   <assign location="state.count" action="increment" />

2. Debugging

   <log label="Debug" expr={({state}) => `Current state: ${state.status}`} />

3. Complex Logic

   <script>
     const result = performCalculation(state.data);
     _dataModel.setValue('state.result', result);
   </script>

4. Event Control

   <cancel sendid="reminder" />

Best Practices

1. State Modifications

   • Use assign for simple state updates
   • Use script for complex calculations
   • Validate data before modifications
   • Keep state changes atomic

2. Event Handling

   • Cancel delayed events when appropriate
   • Handle errors gracefully

3. Debugging

   • Use log elements strategically
   • Include relevant context in logs
   • Consider log levels
   • Clean up debug logs in production

4. Code Organization

   • Keep scripts focused and modular
   • Document complex operations
   • Use meaningful identifiers
   • Follow consistent patterns

See Also

• Control Flow Elements
• State Elements
• SCXML Elements
• Best Practices