Facelets - setting locale via link

Question

Hello Everyone,
I am developing a small web app. A file upload with additional params, its processing on submit and returning the final chart (an image). There are two links for switching to another locale and one for a help page.
The first version was made as JSP page with EL tags and backing servlet. It worked fine but I found the final image can't be saved on local disk. Later I figured out it is caused by browser behaviour during 'save' action, when the servlet is called again (if the image is not already in cache), but as original parameters are missing in this phase, creating of the final image fails.
Trying to solve my problem I've found PRG pattern [1] which seems to be promising answer. I've chosen facelets framework (Mojarra) and tried to refactor app logic a bit. As I see, the complexity of the whole solution grows... and not everything I am able to solve...
My current blocker is a language switcher. What could be in JSP made relatively easy using the following code at the beginning:
<c:if test="${param['locale'] != null}">
  <fmt:setLocale value="${param['locale']}" scope="session" />
</c:if>and handled by very simple links:
<a href="index.jsp?locale=en-GB">English</a> | <a href="index.jsp?locale=cs-CZ">Czech</a>is now unsolvable issue for me.
After long trial error path I set up the following way, but it still doesn't work properly.
In xhtml:
<f:view encoding="utf-8" locale="#{localeBean.locale}">
<h:form>
  <h:commandLink action="#{localeBean.setLocaleEx}">
    <f:setPropertyActionListener
       target="#{localeBean.locale}" value="en"/>
    English
  </h:commandLink>
  <h:commandLink action="#{localeBean.setLocaleEx}">
    <f:setPropertyActionListener
       target="#{localeBean.locale}" value="cs"/>
    Czech
  </h:commandLink>
  <h:outputText value="#{localeBean.locale}" />
  ...In Bean:
@ManagedBean
@RequestScoped
public class localeBean {
    protected String locale = "cs";
    public String getLocale() {
        return locale;
    public void setLocale(String locale) {
        this.locale = locale;
    public void setLocaleEx() {
}Click on generated link really change localeBean.locale value which is displayed using directive h:outputText, but...
1. refreshing of the page is very very slow on my quite recent PC (I use Tomcat 6 as the container - the JSP delay was undetectable)
2. no locale is changed (a f:view locale atribute is probably ignored)
3. in the final HTML page there is a quite long JavaScript
... so unacceptable for me.
Can I create links which can change locale more straigforward and reliable way? And without that JavaScript?
Can I set f:view locale using any parameter sent using a simple URL link like Czech ? I need this setting also for Help page, so a session scope is required. Can this be done via facelets?
Curently I am puzzled a bit...
Thanks in advance for any hint.
Regards,
Jan
[1] [http://blogs.sun.com/enterprisetechtips/entry/post_redirect_get_and_jsf|http://blogs.sun.com/enterprisetechtips/entry/post_redirect_get_and_jsf]

Answer 1

ad 1) refreshing of the page is much better now (maybe there was a memory problem)
ad 2) locale seems to be updated, but I still don't know why my strings are not localized according to this locale
ad 3) if JavaScript is disabled in a browser, switching of locale doesn't work anymore. It would be better to avoid JS at all, but I resigned.
I've found my initial approach is wrong. When some form values are edited and locale is changed in a proposed way, these parameters are reset to their default values.
What I probably need is applying PRG pattern also on this part - somehow to set a new locale and then refresh the same page. I've tried that using 'metada' element at the begining of the page, but it is not very clear how to change locale via commandlink:
<f:metadata>
   <f:viewParam name="loc" value="#{localeBean.locale}" />
</f:metadata>
<f:view encoding="utf-8" locale="#{localeBean.locale}">
<f:loadBundle basename="messages" var="i18n" />
<h:commandLink action="index?faces-redirect=true&includeViewParams=true">
   <f:setPropertyActionListener target="#{localeBean.locale}" value="cs"/>
   Czech
</h:commandLink>as I am getting message when this link is clicked: Conversion Error setting value 'en' for 'null Converter'.
('en' is the default locale set directly in the backing bean)
There is probably impossible to use 'setPropertyActionListener' in this kind of command link, but I have no better idea.
Tu sumarize that, I need a form with two links for switching texts to another locale and one submit button for sending form data to my servlet, all that using PRG pattern to avoid resubmitting once sent data. I prefer the simplest solution.
From my point of view this is the basic feature of any web and I am quite upset that it is still unclear how to resolve it.
Jan