Just as an addition to above answers, there could be following places where you need to implement internationalisation or fetch the message from message bundles.
- views
- controllers
- services
- Filters
- Utility files(e.g. in util package or generalised exception message handling)
- Special files e.g. in Shiro security rest realms
Below are the elaborate usage scenarios:
Views:- we have taglib available with message tag. Use this on views.
controllers :- message method is by default available here and locale conversion is automatically handled. See enter link description here
service: we may call taglibs inside services as below:
def myCustomTaglib = grailsApplication.mainContext.getBean('com.custom.MyCustomTagLib');
Or inject messageSource bean as
def messageSource
4.Filters / utility / Special files:- For these you may create something like below and then use it throughout.
String i18nMessage(def input,String defaultMessage) {
String[] languageCode = RequestContextHolder.currentRequestAttributes().request.getHeader("Accept-Language").split("-")
Locale locale = languageCode.length == 2 ? new Locale(languageCode[0], languageCode[1]) : new Locale(languageCode[0])
String message = defaultMessage
try {
message = messageSource.getMessage(input.code,input?.args?.toArray(),locale)
}catch (NoSuchMessageException nsme ){
log.info("No such error message--> ${nsme.getMessage()}")
}
return message
}
Also, if you get exception below:
java.lang.IllegalStateException: No thread-bound request found: Are you referring to request attributes outside of an actual web request, or processing a request outside of the originally receiving thread? If you are actually operating within a web request and still receive this message, your code is probably running outside of DispatcherServlet/DispatcherPortlet: In this case, use RequestContextListener or RequestContextFilter to expose the current request.
Then, you might need to add request listener to your web.xml
<listener>
<listener-class>
org.springframework.web.context.request.RequestContextListener
</listener-class>
</listener>
Note: web.xml is not available by default, you need to generate it from template.
These are the most common places you might need message bundle conversions.
Solution at point 4 would work in almost all cases. If you notice locale has been handled here manually which we could pass after fetching from requestHeader or request params optionally.
Hope it helps.