Localized Date with Dojo and Spring

We have developed a simple application in which we need to have localized date objects with Dojo DateTextBox on Spring Roo. The problem is that Spring JS does not completely honor the original widget attributes of Dojo considering the date patterns that are specified. To specific, we need to have date patterns of MM/dd/yyyy on English locales and dd-MM-yyyy on Dutch locales.

Localized Date Patterns
We have two property files, namely, application.properties and application_nl.properties to hold the localized messages. Using the two, we added a key to the files holding the localized date pattern:

date.pattern=MM/dd/yyyy

and

date.pattern=dd-MM-yyyy

Configuring a localized CustomDateEditor
To achieve this, first, we need a controller which is aware of localized date patterns defined above; simply, we make the controller an instance of MessageSourceAware so that the applications's localized message source is injected.

public class AbstractController implements MessageSourceAware {

 protected final Log logger = LogFactory.getLog(getClass());

 @Resource
 @Qualifier("messageSource")
 protected MessageSource messages;

 @InitBinder
 public void initBinder(WebDataBinder binder) {
  binder.registerCustomEditor(Date.class, getCustomDateEditor());
 }

 protected CustomDateEditor getCustomDateEditor() {
  String datePattern = messages.getMessage(Constants.DATE_PATTERN_KEY, new Object[] {}, getLocale());
  logger.debug("Customer editor for date pattern: " + datePattern);
  return new CustomDateEditor(new SimpleDateFormat(datePattern), true);
 }

 protected Locale getLocale() {
  Locale locale = getDefaultLocale();
  try {
   locale = LocaleContextHolder.getLocale();
  } catch (Exception e) {
  }
  logger.debug("Current Locale: " + locale);
  return locale;
 }
 
 protected Locale getDefaultLocale() {
  return Locale.US;
 }

 @Override
 public void setMessageSource(MessageSource messageSource) {
  this.messages = messageSource;
 }

}

So, when the controller is initializing the MVC, it registers a custom date editor which is based on the current locale. The use of LocaleContextHolder is interesting as it holds (through ThreadLocal) the locale currently set for the FrameworkServlet in the current thread.

Customizing Dojo DateTextBox
Now, we can simply add a localized DateTextBox to a form:

<spring:message code="date.pattern" var="datePattern" />
<script type="text/javascript">
 Spring.addDecoration(new Spring.ElementDecoration({
  elementId : 'myFormInputId',
  widgetType : 'dijit.form.DateTextBox',
  widgetAttrs : {
   constraints: {min: new Date().setDate(0), max: new Date().setDate(31), datePattern: '${datePattern}'},
   promptMessage : 'Prompt Message',
   invalidMessage : 'Validation Message',
   required : true,
   datePattern : '${datePattern}',
  }
 }));
</script>

Note that, originally, the second datePattern is enough, however, as integration of Spring JS and Dojo is not complete, so you need the additional constraint on the datePattern.