Multiple UAs tutorial

In this tutorial, we will learn about developing User Applications using the uaConfig property. We will reuse the UA tutorial, and replace the unique module used for the eventAppli by two different scripts.

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

Multiple UAs tutorial architecture

We will split the User Application in two User Applications:

• The first module will subscribe to the published value and show this value on the ARINC 661 Layer
• The second module will show a ToggleButton on the same ARINC 661 Layer and sends an event when the user clicks on this toggle

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 Applications

Our two User Applications will still be coded in Java.

Developing the first User Application

The first module subscribe to the published value and show this value on the ARINC 661 Layer:

• The subscribe(ServiceInstance) method will be fired when the User Application module is notified from the publish Service

      public class UATutorial extends AbstractFunctionalUA {
         private static final int LAYER = 1;
         private static final int TOGGLE_BUTTON = 1;
         private static final int LABEL = 2;

         public UATutorial() {
         }

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

Developing the second User Application

The second module show a ToggleButton on the same ARINC 661 Layer and sends an event when the user clicks on this toggle:

• The init() method will be used to add the listener which will listen to the click on the ToggleButton and invoke the event Service

      public class UATutorial2 extends AbstractFunctionalUA {
         private static final int LAYER = 1;
         private static final int TOGGLE_BUTTON = 1;
         private SendEventServiceInstance eventService = null;

         public UATutorial2() {
         }

         public void init() {
           this.eventService = (SendEventServiceInstance) module.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) {
                 logger.error(module, ex.getMessage());
               }
             }
           });
         }
      }

Setting the User Applications configuration

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

      <properties>
         <application name="uaappli" >
            <module name="uaappli" >
               <moduleProperty key="uaConfig" value="uaTutorial.xml"  />
               <moduleProperty key="a661Config" value="a661/tutorial.properties" />
               <moduleProperty key="includeServer" value="true" />
            </module>
         </application>
      </properties>

The "uaTutorial.xml" specifies the two UA Applications, each coded as a Java module:

      <uas>
         <ua url="UATutorial.jar" path="org.da.protoframework.tutorial.uaappli.UATutorial" defaultSubscribeService="published"> 
            <layers>
               <layer appliID="1" layerID="1" />
            </layers>
            <subscribe service="published" >
               <entryPoint method="subscribe" />
            </subscribe>
         </ua>
         <ua url="UATutorial.jar" path="org.da.protoframework.tutorial.uaappli.UATutorial2"> 
            <layers>
               <layer appliID="1" layerID="1" />
            </layers>
         </ua>         
      </uas>