Best practise to retrieve user specified UI Locale in ADF BC Model

Question

Hello,
Situation:
In my application the UI locale is based on a Managed Bean property by using the locale attribute of the f:view tag. e.g. <f:view locale=#{SessionInfo.currentLocale}>.
The user has the ability to change the UI locale by means of a simple popup which contains a <af:commandLink> with a <af:setActionListener from="#{locale}" to="#{Session.currentLocale}"/> for every supported locale.
Questions:
<ul>
<li>Which is the best way to make the current UI locale available on the Model?</li>
<li>Are there other (better) solutions then the once I propose?</li>
</ul>
Possible solutions:
<ol>
<li>Use the BindingContext in the SessionInfo Managed Bean to retrieve the RootApplicationModule and store the locale in the Session UserData Map. This requires to overwrite the activateState and passivateState methods to prevent problems when the AM is released to the pool.</li>
<li>Use the ADFContext object to store the UI locale on the HTTP Session object by using ADFContext.getCurrent().getSessionScope(). The ADFContext object is shared between the UI and the Model.</li>
<li>Use the ADFContext object and its locale property e.g. ADFContext.getCurrent().setLocale(locale)</li>
</ol>
Remarks:
Solution 1: should be chosen when you are working in a clustered environment.
Solution 2: can be difficult to work with in clustered environments since its hard to share the HttpSession object over different clusters.
Solution 3: I'm not sure if this works! The JavaDoc isn't very helpful.
Environment:
Oracle JDeveloper Studio Edition Version 11.1.1.2.0 Build JDEVADF_MAIN_GENERIC_090826.1233.5475 on MicroSoft Windows 7
Oracle RDBMS 11gR1 on Microsoft Windows Server 2003.
Regards,
Steven.

Answer 1

Frank,
Thanks for the hint.
I have read the thread and gave the example by Steve Munch a go (Updated URL to the example on [Steve Munch Dive into ADF Blog|http://blogs.oracle.com/smuenchadf/examples/#95] ).
Since I'm using ADF 11g and the example given is for ADF 10g I had to make some modifications to the example in order to make it work.
Let me explain in short the difference for the people who are interested:
<u>Extending the ADF/Faces Lifecycle</u>
Since the ADF 10g ADFPhaseListener class has become deprecated in ADF 11g we have to use a different approach.
Instead of using the CustomADFPhaseListener and CustomFacesPageLifecycle classes for extending the ADF/Faces Lifecycle we have to use the a custom oracle.adf.controller.v2.lifecycle.PagePhaseListener.
In this class we overwrite the beforePhase method and use a slightly modified version of Steve's code.
public void afterPhase(PagePhaseEvent pagePhaseEvent) {
if (ADFLifecycle.PREPARE_RENDER_ID == pagePhaseEvent.getPhaseId()) {
    App app = (App)ELHelper.get("#{App}");
    Locale preferredLocale = app.getPreferredLocale();
    UIViewRoot uiViewRoot = FacesContext.getCurrentInstance().getViewRoot();
    boolean changedLocale = false;
    if (preferredLocale == null) {
      app.setPreferredLocale(uiViewRoot.getLocale());
    } else {
      if (preferredLocale != uiViewRoot.getLocale()) {
        uiViewRoot.setLocale(preferredLocale);
        changedLocale = true;
    if (changedLocale) {
      for (ControlBinding cb : (List<ControlBinding>)pagePhaseEvent.getLifecycleContext().getBindingContainer().getControlBindings()) {
        if (cb instanceof JUCtrlListBinding) {
          JUCtrlListBinding lb = (JUCtrlListBinding)cb;
          // If the list has a translatable null value
          if (lb.hasNullValue()) {
            // Force the list of values for the list binding to be recalculated
            // so that the null value text will be in the new locale.
            ((JUCtrlListBinding)cb).setValueList(null);
}Next we need to register this CustomPagePhaseListener. This should be done in the adf-settings.xml configuration file.
This file should be placed at *\ViewController\adfmsrc\META-INF* where ViewController is the name of your ADF Rich Faces project.
Example of adf-settings.xml file content.
<?xml version="1.0" encoding="UTF-8" ?>
<adf-settings xmlns="http://xmlns.oracle.com/adf/settings> ">
   <adfc-controller-config xmlns="http://xmlns.oracle.com/adf/controller/config">
      <lifecycle>
         <phase-listener>
            <listener-id>CustomPagePhaseListener</listener-id>
            <class>CustomPagePhaseListener</class>
         </phase-listener>
      </lifecycle>
   </adfc-controller-config>
</adf-settings>Good information about extending the Faces Lifecycle is found in the Fusion Middleware Fusion Developer's Guide chapter [19.4 Customizing the ADF Page Lifecycle|http://download.oracle.com/docs/cd/E15051_01/web.1111/b31974/adf_lifecycle.htm#CIAJGBID]
Hope this information is useful.
Regards,
Steven.
Edited by: StevenJanssens on 12-apr-2010 3:39
Used correct forum layout tags for code examples