rh:methodExpressionListener

This JSF/ADF component allows for multiple listeners on a component that each execute a MethodExpression. An example is the easiest way to understand this:

<af:button text="Multi Action" id="b1">
  <rh:methodExpressionListener method="#{backingBeanScope.myBean.methodOne}"   type="action"/>
  <rh:methodExpressionListener method="#{backingBeanScope.myBean.methodTwo}"   type="action"/>
  <rh:methodExpressionListener method="#{backingBeanScope.myBean.methodThree}" type="action"/>
</af:button>

rh:methodExpressionListener is similar to the built-in af:setPropertyListener or any other of the ADF listeners. The key difference is that this methodExpressionListener executes an EL method expression instead of some pre-defined action. This allows for maximum flexibility and can make it very clear in the JSF page that a button performs multiple actions instead of hiding that in a single actionListener with multiple responsibilities in that single listener

Combining with built-in ADF listeners

The methodExpressionListener can also be combined with the built-in ADF listeners:

<af:button text="Multi Action" id="b1">
  <af:setPropertyListener from="xxx" to="#{backingBeanScope.myBean.someProperty}" type="action"/>
  <rh:methodExpressionListener method="#{backingBeanScope.myBean.methodOne}"      type="action"/>
</af:button>

Invoking ADF Model operation bindings

rh:methodExpressionListener can also execute operation binings from the page definition. This makes it possible to execute multiple ADFm actions:

<af:button text="Multi ADFm" id="b2">
  <!-- create new row in a datacontrol collection -->
  <rh:methodExpressionListener method="#{bindings.Create.execute}"      type="action"/>
  <!-- navigate to next row in a datacontrol collection -->
  <rh:methodExpressionListener method="#{bindings.Next.execute}"        type="action"/>
  <!-- execute method exposed on a datacontrol object -->
  <rh:methodExpressionListener method="#{bindings.doSomething.execute}" type="action"/>
</af:button>

Supported event types

Since MethodExpressionListener extends from oracle.adf.view.rich.event.BasePolytypeListener it supports all of the action types supported by its base class. This includes action, calendar, calendarActivity, calendarActivityDurationChange, calendarDisplayChange, contextInfo, dialog, disclosure, focus, item, launch, launchPopup, poll, popupFetch, query, queryOperation, rangeChange, regionNavigation, return, returnPopupData, returnPopup, rowDisclosure, selection, sort, and valueChange:

<af:popup id="p1">
  <rh:methodExpressionListener method="#{backingBeanScope.myBean.popupFetched}" type="popupFetch"/>
  <af:dialog id="d2" title="Dialog">
    <rh:methodExpressionListener method="#{backingBeanScope.myBean.dialogListenerOne}"   type="dialog"/>
    <rh:methodExpressionListener method="#{backingBeanScope.myOtherBean.dialogListener}" type="dialog"/>
    <af:outputText value="Some text" id="ot1"/>
  </af:dialog>
</af:popup>

Basically for type=anyEvent to work the JSF component the listener is trying to attach to has to have a public void addAnyEventListener(AnyEventListener) method. This is also a way to determine the appropriate value for the type attribute of the rh:methodExpressionListener tag. If the JSF component has a public void addSomeOtherEventListener(SomeOtherEvent) method, you know to use type=someOther

Supported methods

The expression from the method attribute has to point to a method accepting a single appropriate FacesEvent subclass like method="#{myBean.clickedButton}" pointing to MyBean's public void clickedButton(ActionEvent event) method. Alternatively it can also point to a method accepting no argument as all, such as with #{bindings.Create.execute}.

Exception handing

rh:methodExpressionListener will throw a javax.faces.event.AbortProcessingException Whenever an exception occurs during execution of the MethodExpression. This aborts any other pending listeners. It will also throw this AbortProcessingException if it invokes an ADF Model methodthat don't throw an exception themselves but report them to the BindingContainer. For example

<af:button text="Multi Action" id="b1">
  <rh:methodExpressionListener method="#{bindings.Delete.execute}" type="action"/>
  <rh:methodExpressionListener method="#{bindings.Commit.execute}" type="action"/>
</af:button>

will not execute the Commit action if the Delete action failed and reported an exception to the BindingContainer, for example when no current row is available to delete.

Usage

• Download the latest release JAR from https://github.com/wvanderdeijl/adf-method-listener/releases
• In the consuming application go to Project Properties, then Facelet Tag Libraries. Click the Add button and make sure to select the Project folder in the popup. Then press the New button and browse to the method-listener.jar.
• When not using Facelets, but JSP pages the steps are similar but use JSP Tag Libraries in the project properties
• This will not only add the JAR file to your project libraries but also register the Facelet tag library