Authorization over UIComponents with JSF 2.0

Question

Hi,
I'm want to access the components of a requested view and to alter the "rendered" attribute based on authorization rules.
Using a Phase Listener I got the components, but only after render response phase, where alterations don't make any effect because the outputStream has already been generated.
This "rendered" attribute need to be set before the render phase.
Is this possible?
Decorating the "HTML_BASIC" render kit? How?
Thanks,
Daniel Almeida

Answer 1

I resolved this decorating the ViewHandler.
1. Extend the ViewHandlerWrapper abstract class;
2. Declare a private ViewHandler for the viewHandler that we decorates;
3. Create a constructor with a ViewHandler parameter;
4. Override the renderView method with the authorization logic;
5. Declare the decorating ViewHandler in faces-config.xml
ViewHandler
public class MyViewHandler extends ViewHandlerWrapper{
    private ViewHandler defaultViewHandler = null;
    public MyViewHandler() {
    public MyViewHandler(ViewHandler defaultViewHandler) {
        super();
        this.defaultViewHandler = defaultViewHandler;
    @Override
    public void renderView(FacesContext context, UIViewRoot viewToRender) throws IOException, FacesException {
         viewToRender.visitTree(VisitContext.createVisitContext(context),
            new VisitCallback() {
                @Override
                public VisitResult visit(VisitContext context, UIComponent target) {
                    // Authorization logic here
                    //    target.setRendered(false);
                    return VisitResult.ACCEPT;
        defaultViewHandler.renderView(context, viewToRender);
    @Override
    public ViewHandler getWrapped() {
        return defaultViewHandler;
    }faces-config.xml
    <application>
        <view-handler>org.something.MyViewHandler</view-handler>
    </application>