JavaServer Faces lifecycle context

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This topic shows you the JViews JSF code for installing a select object interactor and a listener. It also shows you the Java™ code for writing a value-change event listener.

In JViews Diagrammer

To select an SDM node in a view, a select object interactor must be installed on the diagram component view. The value property of the interactor holds the IlvSDMNode object that was clicked. Thus, a valueChangeListener can be registered to handle the selection event.

Installing a select node or link interactor and a listener

<jvdf:nodeOrLinkSelectInteractor id="objSelect"
     valueChangeListener="#{diagrammerBean.onSelectNode}"
                 invocationContext="JSF_CONTEXT"/>

<jvdf:diagrammerView id="diagrammer" interactorId="objSelect" [...] />

Note

JSF_CONTEXT is the default value, so the invocationContext attribute could have been omitted.

Java code of the value-change event

The Java code of the value change event listener is:

  public void onSelectNode(ValueChangeEvent event) {
    IlvSDMNode node = (IlvSDMNode) event.getNewValue();
    if (node != null) {

         //The source of the event is the interactor
         IlvFacesNodeOrLinkSelectInteractor source =
              (IlvFacesNodeOrLinkSelectInteractor)valueChangeEvent.getSource();

               //Retrieve the JSF view connected to the interactor
               IlvFacesDiagrammerView jsfDiagrammer =
                 (IlvFacesDiagrammerView)source.getView();

      try {
        //Retrieve the IlvDiagrammer wrapped by the JSF component.
        IlvDiagrammer diagrammer = jsfDiagrammer.getDiagrammer();

                //Select the clicked object
        diagrammer.deselectAll();
        diagrammer.setSelected(node, true);

      } catch (Exception e) {
        e.printStackTrace();
      }
    }
  }

At the JViews Framework level

To select a graphic object in a view at the JViews Framework level, a select object interactor must be installed on the view. The value property of the interactor holds the IlvGraphic object that was clicked. Thus, a valueChangeListener can be registered to handle the selection event.

Installing a select object interactor and a listener

<jvf:objectSelectInteractor id="objSelect"
     valueChangeListener="#{frameworkBean.selectObject}"
                 invocationContext="JSF_CONTEXT"/>

<jvf:view id="view" interactorId="objSelect" [...] />

Note

JSF_CONTEXT is the default value, so the invocationContext attribute could have been omitted.

Java code of value-change event

The Java code of the value change event listener is:

public void selectObject(ValueChangeEvent event) {
  Object value = event.getNewValue();
  if (value != null && value instanceof IlvGraphic) {

           //The source of the event is the interactor
           IlvFacesObjectSelectInteractor source =
                (IlvFacesObjectSelectInteractor)valueChangeEvent.getSource();

                //Retrieve the JSF view connected to the interactor
    IlvFacesView jsfView = (IlvFacesView)source.getView();

         //Retrieve the IlvManagerView wrapped by the JSF component.
    IlvManagerView managerView = jsfView.getView();

                //Select the clicked object
    IlvGraphic g = (IlvGraphic) value;
    managerView.getManager().deSelectAll(false);
    managerView.getManager().setSelected(g, true, false);
  }
}

Note the following concerning the use of this approach:

Since the method is called during the JavaServer™ Faces lifecycle, there can be interaction with other JSF components.
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