Wait Program Intermediate Event

The Wait Program Intermediate Event element is located in the Event & Gateway drawer of the process editor palette.

Element Details

This element is one of Axon.ivy facilities to integrate custom-made software, legacy systems, proprietary applications or any other external system through an Axon.ivy Java interface. At an Intermediate Event element the process execution is interrupted and waits for an external event to occur. Technically spoken the current task will be ended and a new system task is created that waits for the intermediate event. If the intermediate event is fired the new task and therefore the process after the intermediate event will be executed.

You provide a listener for the external event by implementing a Java class that implements the IProcessIntermediateEventBean interface. The Wait Program Intermediate Event Element instantiates the Java class and can then trigger the intermediate event by calling the method fireProcessIntermediateEventEx on the Axon.ivy runtime engine IProcessIntermediateEventBeanRuntime. The common way to implement an Intermediate Event bean is to extend the abstract base class AbstractProcessIntermediateEventBean. The interface also includes an inner editor class to parametrize the bean. You will find the documentation of the interface and the abstract class in the Java Doc of the Axon.ivy Public API.

Note

An Axon.ivy Engine Enterprise Edition consists of multiple engine instances (nodes) that are running on different machines.

Normally process intermediate event beans are instantiated on every node but only started on the master node. This guarantees that for each Intermediate Event process element only one bean is running, no matter what the total number of nodes in the Engine Enterprise Edition is.

However, if you need your intermediate event bean to be started on all cluster nodes, you may instruct the server to do so. Just have your bean class implement the (empty) marker interface IMultiNodeCapable and the above restriction will no longer apply.

Please be aware of the fact that having multiple running instances of the same bean may lead to race conditions.

Inscription

Name Tab

The Name Tab is included in the mask of all process elements and contains the name and a description of the element.

Event Tab

On this tab you define the Java class that the IntermediateEvent should instantiate, the identifier of the event to wait for and the timeout behaviour.

Java Class to execute

Fully qualified name of the Java class that implements the IProcessIntermediateEventBean interface. Use the New Bean Class Wizard () to create a new Java source file with an example implementation of the bean class.

Event ID

Because multiple cases (process instances) can wait on the same intermediate event you must specify which event belongs to which waiting case. Here you specify the identifier of the event the current case should wait for.

Warning

The event identifier as a String must be unique. Do not use a static string like "myID". A good practice is to integrate the case identifier (ivy.case.getIdentifier()) into the event id.

Timeout

Here you can specify a time (Duration) how long the current case should wait for an intermediate event and what should happen if no event has been received after this time. You can optionally start an exception process, delete the waiting task or continue the waiting task without receiving an intermediate event.

Editor Tab

This tab displays the editor that can be integrated in the external Java bean of the process element. The editor is implemented as an inner public static class of the Java bean class and must have the name Editor. Additionally the editor class must implement the IProcessExtensionConfigurationEditorEx interface. The common way to implement the editor class is to extend the abstract base class AbstractProcessExtensionConfigurationEditor and to override the methods createEditorPanelContent, loadUiDataFromConfiguration and saveUiDataToConfiguration. The method createEditorPanelContent can be used to build the UI components of the editor. You can add any AWT/Swing component to the given editorPanel parameter. With the given editorEnvironment parameter, which is of the type IProcessExtensionConfigurationEditorEnvironment, you can create text fields that support ivyScript and have smart buttons that provide access to the process data, environment functions and Java classes.

Here is an example on how an editor could look like:

As you can see, the editor provides access to any process relevant data that can be used by your own process elements. For instance, you can easily transfer process data to your legacy system.

The following part shows the implementation of the above editor. As mentioned earlier Axon.ivy provides the IIvyScriptEditor that represents a text field with ivyScript support and smart buttons. Inside createEditorPanelContent use the method createIvyScriptEditor from the editorEnvironment parameter to create an instance of such an editor. Use the loadUiDataFromConfiguration method to read the bean configuration and show within the UI components. Inside this method you can use the methods getBeanConfiguration or getBeanConfigurationProperty to read the bean configuration. Use the method saveUiDataToConfiguration to save the data in the UI components to the bean configuration. Inside this method you can use methods setBeanConfiguration or setBeanConfigurationProperty to save the bean configuration.

public static class Editor extends AbstractProcessExtensionConfigurationEditor
{
  private IIvyScriptEditor editorUser;
  private IIvyScriptEditor editorEventTyp;
  private IIvyScriptEditor editorLinkId;
  private IIvyScriptEditor editorFieldValue;

  @Override
  protected void createEditorPanelContent(Container editorPanel,
          IProcessExtensionConfigurationEditorEnvironment editorEnvironment)
  {
    editorPanel.setLayout(new GridLayout(4, 2));
    editorUser = editorEnvironment.createIvyScriptEditor(null, null, "String");
    editorEventTyp = editorEnvironment.createIvyScriptEditor(null, null, "String");
    editorLinkId = editorEnvironment.createIvyScriptEditor(null, null, "String");
    editorFieldValue = editorEnvironment.createIvyScriptEditor(null, null);

    editorPanel.add(new JLabel("User"));
    editorPanel.add(editorUser.getComponent());
    editorPanel.add(new JLabel("Event Typ"));
    editorPanel.add(editorEventTyp.getComponent());
    editorPanel.add(new JLabel("Link-Id"));
    editorPanel.add(editorLinkId.getComponent());
    editorPanel.add(new JLabel("Feldwert"));
    editorPanel.add(editorFieldValue.getComponent());
  }

  @Override
  protected void loadUiDataFromConfiguration()
  {
    editorUser.setText(getBeanConfigurationProperty("User"));
    editorEventTyp.setText(getBeanConfigurationProperty("EventTyp"));
    editorLinkId.setText(getBeanConfigurationProperty("LinkId"));
    editorFieldValue.setText(getBeanConfigurationProperty("Feldwert"));
  }

  @Override
  protected boolean saveUiDataToConfiguration()
  {
    setBeanConfigurationProperty("User", editorUser.getText());
    setBeanConfigurationProperty("EventTyp", editorEventTyp.getText());
    setBeanConfigurationProperty("LinkId", editorLinkId.getText());
    setBeanConfigurationProperty("Feldwert", editorFieldValue.getText());
    return true;
  }
}

At runtime you have to evaluate the IvyScript the user have entered into the ivy script editors. If you implement for example the AbstractUserProcessExtension class there is a perform method which is executed at runtime. At this point you want to access the configured data in the editor. The following code snippet show how you can evaluate the value of an IIvyScriptEditor. If you use the IIvyScriptEditor you only get the value by calling the executeIvyScript method of the AbstractUserProcessExtension.

public CompositeObject perform(IRequestId requestId, CompositeObject in,
     IIvyScriptContext context) throws Exception
{
  IIvyScriptContext ownContext;
  CompositeObject out;
  out = in.clone();
  ownContext = createOwnContext(context);

  String eventtyp = "";
  String linkId = "";
  String fieldValue = "";
  String user= "";

  user = (String)executeIvyScript(ownContext, getConfigurationProperty("User"));
  eventtyp = (String)executeIvyScript(ownContext, getConfigurationProperty("Event Typ"));
  linkId = (String)executeIvyScript(ownContext, getConfigurationProperty("Link-Id"));
  fieldValue = (String)executeIvyScript(ownContext, getConfigurationProperty("Feldwert"));

  // add your call here

  return out;
}

Task Tab

On this tab you configure the task which is created when this element is executed by the awaitet event. This task will not appear in any user task list and is exclusively handled by the system. The values on this tab are therefore only relevant for analysing the finished tasks and not for the task list itself.

Custom fields

The values set on this table are only informational and have no effect on how this task is treated by Axon.ivy. See Custom Fields.

Code

This is a post construct code block for the Task that is defined in this tab. The created Task is provided as variable called task. See Code.

Output Tab

On Output Tab you can configure the output of the element (i.e. the data that leaves the element).

Note

For each incoming connection you have a separate inX object available which carries the data of the Xth input. Hover with the mouse over the incoming connections of the element to learn which input connection corresponds to which variable.