State Machine Code and SCXML Generation

A state machine consists of a number of states and the transition between states. After creating a controller class, create a sub-state machine diagram from the controller class. Finally, you can generate source code based on the sub-state machine diagram. In this tutorial, you will model a controller class and state machine. After all, you will generate state machine code and play with the sample application. Finally, you will export SCXML from your state machine.

August 16, 2010
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Create a new project with VP-UML. Select File > New Project from the main menu. Name the project as Phone Model and click Create Blank Project.
Create a class diagram form Diagram Navigator. Right click on Class Diagram in Diagram Navigator and select New Class Diagram from the pop-up menu.
Create a controller class. Select Class from diagram toolbar, click on the diagram to create a class and name it as PhoneController.
Next, add a few attributes to the controller class. Right click on the class and select Add > Attribute from the pop-up menu.
Enter _dialingNumber : String and press Enter to create the next attribute.
Continue to add attributes as shown below:

Name Type

_incomingCallNumber String

_startTime long

_endTime long

The result of PhoneController class is shown as below:
Add operations to the controller class. Those operations will cause the state to change. Right click on the class and select Add > Operation from the pop-up menu.
Enter PhoneController to add the constructor and press Enter to create the next operation.
Continue to add operations as shown below:

Name Return Type

dial(number : String) : void void

receiveCall void

hangUp void

chat void

The result of PhoneController class is shown as below:
Now, we are going to draw the state machine for PhoneController class. Right click on PhoneController and select Sub Diagram > State Machine Diagram > Create State Machine Diagram from the popup menu.
A state machine diagram is created with an initial node appears. Draw the Dialing state through resource icon. Move the mouse pointer over the initial node, press on its resource icon Transition -> State and drag it out. Release the mouse button until finish creating. Name the state as Dialing.
Follow the image below to create a few more states: Calling, CallReceived, InTalk and CallTerminated and then connect them with transition.
Create the final state from CallTerminated state through resource centric interface.
Now, add a trigger to transitions. Right click on the transition between Dialing state and Calling state. Select Open Specification... from the pop-up menu.
In the Transition Specification dialog box, open Triggers tab. Click Add button and select Call Trigger from the pop-up menu.
In the Call Trigger Specification dialog box, enter Dial as trigger name. Select dial(number : String) : void from the drop down menu of Operation. Click OK button.
The trigger is selected for the transition. Click OK button.
Continue to add a few more triggers following the table below:

Transition Trigger name

Calling -> Call Received Receive Call

CallReceived -> InTalk Chat

InTalk -> CallTerminated Hang up

The completed state machine diagram is shown as follows:
Now, let's do code generation. Select Code > State Machine Code > Generate Code... from the toolbar.
In the Generate State Machine Code, specify the directory to store the generated code and click OK button.
Compile the generated code and run PhoneControllerSample class.

Run the sample application by clicking Proceed button repeatedly and observe the change of states.
Go back to your state machine and export SCXML from the state machine. Right click on the background of diagram and select Export > Export to SCXML from the pop-up menu.
In the Export SCXML dialog box, specify the path of *.scxml file and click OK.
The following image is the exported file in a text editor: