JSF - custom NavigationHandler outcome values invalid? - jsf

Question

I wrote myself a custom NavigationHandler very similar to following one but just using a stack to save the history:
http://jsfatwork.irian.at/book_de/custom_component.html#!idx:/custom_component.html:fig:backnavigationhandler-code
public class HistoryNavigationHandler extends NavigationHandler
{
private final NavigationHandler navigationHandler;
private final Stack<String> outcomes;
public HistoryNavigationHandler(final NavigationHandler navigationHandler)
{
this.navigationHandler = navigationHandler;
this.outcomes = new Stack<String>();
}
#Override
public void handleNavigation(final FacesContext context, final String fromAction, final String outcome)
{
if (outcome != null)
{
if (outcome.equals("back"))
{
final String lastViewId = this.outcomes.pop();
final ViewHandler viewHandler = context.getApplication().getViewHandler();
final UIViewRoot viewRoot = viewHandler.createView(context, lastViewId);
context.setViewRoot(viewRoot);
context.renderResponse();
return;
}
else
{
this.outcomes.push(context.getViewRoot().getViewId());
}
}
this.navigationHandler.handleNavigation(context, fromAction, outcome);
}
}
Registering this one in the faces-config.xml:
<navigation-handler>
package.HistoryNavigationHandler
</navigation-handler>
Results in following log warning and a message where a previously working link was present:
Warning: jsf.outcome.target.invalid.navigationhandler.type
Something like: this link is disabled because a navigation case could not be matched
What is the problem?

Answer 1

Since JSF 2, the NavigationHandler has been replaced by ConfigurableNavigationHandler. All JSF 2 specific tags/components like <h:link> and so on are relying on it. The NavigationHandler is kept for backwards compatibility.
Here's a kickoff example how to properly extend ConfigurableNavigationHandler:
public class HistoryNavigationHandler extends ConfigurableNavigationHandler {
private NavigationHandler wrapped;
public HistoryNavigationHandler(NavigationHandler wrapped) {
this.wrapped = wrapped;
}
#Override
public void handleNavigation(FacesContext context, String from, String outcome) {
// TODO: Do your job here.
wrapped.handleNavigation(context, from, outcome);
}
#Override
public NavigationCase getNavigationCase(FacesContext context, String fromAction, String outcome) {
return (wrapped instanceof ConfigurableNavigationHandler)
? ((ConfigurableNavigationHandler) wrapped).getNavigationCase(context, fromAction, outcome)
: null;
}
#Override
public Map<String, Set<NavigationCase>> getNavigationCases() {
return (wrapped instanceof ConfigurableNavigationHandler)
? ((ConfigurableNavigationHandler) wrapped).getNavigationCases()
: null;
}
}