if (child instanceof UIViewParameter) {
UIViewParameter viewParameter = (UIViewParameter) child;
// Checking if the parameter is required but has an empty value
if (viewParameter.getRequiredMessage() != null && isEmpty(viewParameter.getStringValue(ctx))) {
// Adding the message
FacesMessages messages = BeanInject.lookup(FacesMessages.class);
messages.addEL(viewParameter.getRequiredMessage(), FacesMessage.SEVERITY_ERROR);
// Redirecting to the error page
NavBase nav = BeanInject.lookup(NavBase.class);
String url = ctx.getApplication().getViewHandler().getActionURL(ctx, nav.getError().s());