Question

I’m trying to implement a Custom Naviguation, that do the usual job and update my breadcrumb.

public class CustomNaviguationHandler extends NavigationHandlerImpl{

     public void handleNavigation(FacesContext context, String fromAction, String outcome) {
         //do the breadcrumb update

         super.handleNavigation(context, fromAction, outcome);
     }
}

But when I debug it, the method is executed 2 times once,

1. The 1st time, fromAction and outcome are null
2. The 2nd time, these parameters contains the right values.

The handler has been registered in the faces-config.xml

<navigation-handler>my.package.CustomNaviguationHandler</navigation-handler>

I’m not sure to understant why? Any Idea?

Answer 1

You should not extend the JSF impl class NavigationHandlerImpl at all. You should instead extend the JSF API class NavigationHandler.

Here’s a kickoff example. Do your job in the handleNavigation() method. If you don’t want to take responsibility on navigation, delegate to the parent.

public class CustomNavigationHandler extends NavigationHandler {

    private NavigationHandler parent;

    public CustomNavigationHandler(NavigationHandler parent) {
        this.parent = parent;
    }

    @Override
    public void handleNavigation(FacesContext context, String from, String outcome) {
        parent.handleNavigation(context, from, outcome);
    }

}