Component binding and Value change listeners

Question

Hi -
I'm fairly new to JSF and are having a few teething problems.
I have a date component in my registration page. Its made of up 3 text inputs (1 each for day, month, year). Since these need to be validated as a group I use a method in my backing bean (request scoped) to do this. (I saw this demonstrated in Core JSF).
Here's my code for the date components:
<h:outputLabel value="#{register.labelData.dateOfBirth}" /><br />
<h:message for="day" styleClass="error" />
<h:inputText id="year" styleClass="input smaller" maxlength="4" value="#{register.dateOfBirthYear}" binding="#{register.dobYearInput}" onfocus="doOnFocus('registerForm:year')" onblur="doOnBlur('registerForm:year')" tabindex="12" />
<h:inputText id="month" styleClass="input smallest" maxlength="2" value="#{register.dateOfBirthMonth}" binding="#{register.dobMonthInput}" onfocus="doOnFocus('registerForm:month')" onblur="doOnBlur('registerForm:month')" tabindex="13" />
<h:inputText id="day" styleClass="input smallest" maxlength="2"  value="#{register.dateOfBirthDay}" binding="#{register.dobDayInput}" validator="#{register.validateDate}" required="true" requiredMessage="#{register.msgData.dobMandatory}" onfocus="doOnFocus('registerForm:day')" onblur="doOnBlur('registerForm:day')" tabindex="14" />Now this works great.
The other feature I have on the page is a select box so the page can be displayed in different languages. My application stores the current language in a session scoped bean. I have attached a value change listener onto the select box so the session is updated with the new language.
<h:outputLabel for="languageSwitch" value="#{sessionBean.labelData.langSwitch}" />
<h:selectOneMenu id="languageSwitch" styleClass="select" onchange="submit()" immediate="true" value="#{sessionBean.language}" valueChangeListener="#{sessionBean.changeLanguage}">
    <f:selectItems value="#{sessionBean.languages}" />
</h:selectOneMenu>The request scoped beans have a reference to this session scoped bean, and use it to look up the page text in the appropriate language from the DB. IE:
String label = getMessage(getSession().getLocale());The problem is on the registration page - because the date controls are bound to the managed bean the bean is (re-)created in the RESTORE_VIEW phase, BEFORE the value in the session has been update in the PROCESS_VALIDATIONS phase.
I'm a little puzzled as to how berst to fix this problem - so any ideas that anyone has would be gratefully received.
Thanks -
Edited by: mbea023 on Jul 20, 2008 9:18 PM

Answer 1

Thanks for the reply Raymond -
The request scoped beans don't actually store the Locale directly - they have a reference to the SessionBean which store the locale. So they determine the locale by the following:
Locale currentLocale = getSessionBean().getLocale();The reference to the SessionBean is injected (by Spring) in the constructor of the request scoped bean. Then, in the constructor, the request bean queries the DB for the language specific text to display on the page. EG:
public MyRequestScopedBean {
String message = messageAccessor.getMessage(messageKey, currentLocale);
}Unfortunately it is a requirement to use a DB to store messages, so we can't use resource-bundles.
Firstly, Is this the best way of request scoped beans having a reference to the session? Or is there a better way.
The problem occurs when I have a page that has control bound to the request scoped bean ie:
<h:XXXX binding="myRequestBean.ZZZ />
{code}
Then the constructor of the request bean runs *before* the value of the locale is changed in the sessionBean - this means the page messages are looked up with the old locale.
Any further advice would be a great help - Thanks