Baztoune/application_fr.properties

## application_fr.properties
my.var=BlahdeBlih
other.var=ROFLOL

## application_fr_FR_MYVARIANT
my.var=DeBlihDaBlouh

## child.xhtml
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<ui:composition xmlns="http://www.w3.org/1999/xhtml"
  xmlns:h="http://java.sun.com/jsf/html"
	xmlns:ui="http://java.sun.com/jsf/facelets"
	xmlns:f="http://java.sun.com/jsf/core"
	xmlns:s="http://jboss.com/products/seam/taglib"
	xmlns:rich="http://richfaces.org/rich"
	xmlns:a4j="http://richfaces.org/a4j" template="/layout/template.xhtml">

	<ui:param name="locale_variant"	value="#{myBean.parameter.name()}" />

	<ui:define name="body">
    #{appMsg['my.var']}
  </ui:define>
</ui:composition>

## faces-config.xml
<?xml version="1.0" encoding="UTF-8"?>
<faces-config version="1.2" xmlns="http://java.sun.com/xml/ns/javaee"
  xmlns:xi="http://www.w3.org/2001/XInclude" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-facesconfig_1_2.xsd">
	<application>
		<view-handler>com.sun.facelets.FaceletViewHandler</view-handler>
		<message-bundle>messages</message-bundle>
		<locale-config>
			<default-locale>fr</default-locale>
			<supported-locale>fr</supported-locale>
			<supported-locale>fr_FR_MYVARIANT</supported-locale>
      <supported-locale>fr_FR_MYSECONDVARIANT</supported-locale>
		</locale-config>
		<resource-bundle>
			<base-name>application</base-name>
			<var>appMsg</var>
		</resource-bundle>
	</application>
</faces-config>

## resource_bundle_and_locale_variant_JSF.md

      
    Raw
  

              resource_bundle_and_locale_variant_JSF.md
            
          
    Depending on the page, my client needed to customize the labels depending on some variable. I wanted to use the i18n mechanism provided by JSF, so it can fallback to a default label and use a custom one when available.
The difficult part was actually to set the locale, depending on a parameter. A solution would have been to extend the ViewHandler and override the calculateLocale() method, but it wasn't a good fit (I didn't manage to access the conversation context, also the locale depends on various values depending on the page you're on). Defining a var in child pages and setting the locale in the root f:view worked like a charm (even though it's ugly).
<f:view locale="#{locale_variant eq null?'fr':'fr_FR_'}#{locale_variant}" />

<ui:param name="locale_variant"  value="#{myBean.parameter.name()}" />

<supported-locale>fr_FR_MYVARIANT</supported-locale>


## template.xhtml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">

<f:view xmlns="http://www.w3.org/1999/xhtml"
  xmlns:ui="http://java.sun.com/jsf/facelets"
	xmlns:f="http://java.sun.com/jsf/core"
	xmlns:h="http://java.sun.com/jsf/html"
	xmlns:a="http://richfaces.org/a4j"
	xmlns:notify="http://richfaces.org/sandbox/notify"
	xmlns:s="http://jboss.com/products/seam/taglib" contentType="text/html"
	locale="#{locale_variant eq null?'fr':'fr_FR_'}#{locale_variant}">

	<f:loadBundle basename="application" var="msg" />

	<html>
    <head>
      <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
      <title>Servidom</title>
      <link rel="shortcut icon" href="#{request.contextPath}/favicon.ico" />
      <ui:insert name="head" />
      <script type="text/javascript">window.RICH_FACES_EXTENDED_SKINNING_ON=false;</script>
      <a:loadStyle src="/stylesheet/normalize.css" />
      <a:loadStyle src="/stylesheet/main.css" />
      <ui:insert name="moreStyles" />
      <ui:insert name="moreScripts" />
    </head>

    <body>
    	<ui:insert name="body" />
    </body>
	</html>
</f:view>
	<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
	"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
	<ui:composition xmlns="http://www.w3.org/1999/xhtml"
	xmlns:h="http://java.sun.com/jsf/html"
	xmlns:ui="http://java.sun.com/jsf/facelets"
	xmlns:f="http://java.sun.com/jsf/core"
	xmlns:s="http://jboss.com/products/seam/taglib"
	xmlns:rich="http://richfaces.org/rich"
	xmlns:a4j="http://richfaces.org/a4j" template="/layout/template.xhtml">

	<ui:param name="locale_variant" value="#{myBean.parameter.name()}" />

	<ui:define name="body">
	#{appMsg['my.var']}
	</ui:define>
	</ui:composition>
	<?xml version="1.0" encoding="UTF-8"?>
	<faces-config version="1.2" xmlns="http://java.sun.com/xml/ns/javaee"
	xmlns:xi="http://www.w3.org/2001/XInclude" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-facesconfig_1_2.xsd">
	<application>
	<view-handler>com.sun.facelets.FaceletViewHandler</view-handler>
	<message-bundle>messages</message-bundle>
	<locale-config>
	<default-locale>fr</default-locale>
	<supported-locale>fr</supported-locale>
	<supported-locale>fr_FR_MYVARIANT</supported-locale>
	<supported-locale>fr_FR_MYSECONDVARIANT</supported-locale>
	</locale-config>
	<resource-bundle>
	<base-name>application</base-name>
	<var>appMsg</var>
	</resource-bundle>
	</application>
	</faces-config>
	<?xml version="1.0" encoding="UTF-8"?>
	<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">

	<f:view xmlns="http://www.w3.org/1999/xhtml"
	xmlns:ui="http://java.sun.com/jsf/facelets"
	xmlns:f="http://java.sun.com/jsf/core"
	xmlns:h="http://java.sun.com/jsf/html"
	xmlns:a="http://richfaces.org/a4j"
	xmlns:notify="http://richfaces.org/sandbox/notify"
	xmlns:s="http://jboss.com/products/seam/taglib" contentType="text/html"
	locale="#{locale_variant eq null?'fr':'fr_FR_'}#{locale_variant}">

	<f:loadBundle basename="application" var="msg" />

	<html>
	<head>
	<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
	<title>Servidom</title>
	<link rel="shortcut icon" href="#{request.contextPath}/favicon.ico" />
	<ui:insert name="head" />
	<script type="text/javascript">window.RICH_FACES_EXTENDED_SKINNING_ON=false;</script>
	<a:loadStyle src="/stylesheet/normalize.css" />
	<a:loadStyle src="/stylesheet/main.css" />
	<ui:insert name="moreStyles" />
	<ui:insert name="moreScripts" />
	</head>

	<body>
	<ui:insert name="body" />
	</body>
	</html>
	</f:view>