Scripted UA tutorial

In this tutorial, we will learn about developing a Scripted UA. We will reuse the UA tutorial, and replace the Java User application which replaced the eventAppli of the first tutorial by a Groovy Script.

For this tutorial, you should have already mastered the previous tutorial about developing a Java-coded UA.

Overview

UA Application tutorial architecture

The UA tutorial defined two services:

• One Service published a value
• Another Service published the state of a toggle button in case of a click event

And two applications:

• The first PublishModule had no graphical interface and:
• Incremented or decremented the value
• Published cyclically the value
• Listened to the toggle event to set if the value should increment or decrement
• A User Application, embedded in a built-in UA application, which will:
• Subscribe to the published value and show this value on an ARINC 661 Layer
• Show a ToggleButton on the ARINC 661 Layer and sends an event when the user clicks on this toggle

Scripted UA Application tutorial architecture

We will replace the Java-coded User Application by a Groovy script.

The new architecture is:

Keeping the configuration

We will keep:

• The types.xml
• The services.xml
• The applications.xml, because we will keep the same UA Application. It's only the configuration of the UA Application itself which will change

We will also keep:

• The Definition File
• The Windowing Configuration
• The ARINC 661 configuration for both the ARINC 661 Client and the ARINC 661 Server

Developing the User Application

Our User Application will now be coded in Groovy: Now we will develop our User Application:

• The init() method will be used to add the listener which will listen to the click on the ToggleButton and invoke the event Service
• The subscribe(ServiceInstance) method will be fired when the User Application module is notified from the publish Service

      int LAYER = 1;
      int TOGGLE_BUTTON = 1;
      int LABEL = 2;
      SendEventServiceInstance eventService = null;

      public void init() {
        this.eventService = (SendEventServiceInstance) context.getModule().getService("event");
        // listen to widgets events
        api.addWidgetEventListener(LAYER, TOGGLE_BUTTON, new ARINCEventListener() {
          public void eventReceived(ARINCEvent evt) {
            WidgetEvent widgetEvt = (WidgetEvent) evt;
            try {
              boolean isSelected = ((Boolean) widgetEvt.getValues().get(0));
              eventService.setDataBooleanValue("event", isSelected);
              eventService.invoke();
            } catch (ARINCRuntimeException ex) {
              context.error(ex.getMessage());
            }
          }
        });
      }

      public void subscribe(ServiceInstance service) {
        if (helper.hasChanged("value")) {
          String value = helper.getStringValue("value");
          api.setWidgetParameter(LAYER, LABEL, ARINC661.A661_STRING, value);
          api.sendAll();
        }
      }

Setting the User Application configuration

Now we will need to specify the properties of the UA application:

      <properties>
         <application name="uaappli" >
            <module name="uaappli" >
               <moduleProperty key="script" value="uaScript.groovy"  />
               <moduleProperty key="a661Config" value="a661/tutorial.properties" />
               <moduleProperty key="includeServer" value="true" />
            </module>
         </application>
      </properties>