code: private String determineLanguage(FacesContext fc, DataTable dataTable) {
  		final List<String> availableLanguages = Arrays.asList("de", "en", "es", "fr", "hu", "it", "nl", "pl", "pt",
  				"ru");
  		if (BsfUtils.isStringValued(dataTable.getCustomLangUrl())) {
  			return dataTable.getCustomLangUrl();
  		} else if (BsfUtils.isStringValued(dataTable.getLang())) {
  			String lang = dataTable.getLang();
  			if (availableLanguages.contains(lang)) {
  				return determineLanguageUrl(fc, lang);
  			}
  		} else {
  			String lang = fc.getViewRoot().getLocale().getLanguage();
  			if (availableLanguages.contains(lang)) {
  				return determineLanguageUrl(fc, lang);
  			}
  		}
  		return null;
  	}
docs: Determine if the user specify a lang Otherwise return null to avoid language
  settings.
  
  @param fc
  @param dataTable
  @return