Exposing message.properties to javascript?

Question

Is there an easy way to expose all translated strings to javascript? I want to be able to use translated strings in my JS files without manually building them in GSPs.

Is there an easy way to do this?

Answer 1

The Jawr plugin (good plugin to use to optimize your JS and CSS resources anyway) can expose parts or the whole of your i18n message bundles to Javascript:

http://jawr.java.net/docs/messages_gen.html

Answer 2

Expose i18n/messages.properties as JSON

I18nController.groovy

package myproject

import grails.converters.JSON
import grails.plugin.springsecurity.annotation.Secured

@Secured("permitAll")
class I18nController {
  static defaultAction = "index"

  I18nService i18nService

  def index() {
    render i18nService.getAllTranslations(params, request) as JSON
  }
}

I18nService.groovy

package myproject

import grails.transaction.Transactional
import grails.web.servlet.mvc.GrailsParameterMap
import org.springframework.context.MessageSource

import javax.servlet.http.HttpServletRequest

@Transactional
class I18nService {

  MessageSource messageSource
  LocaleService localeService

  /**
   * http://www.razum.si/blog/grails-javascript-i18n-messages
   * @return
   */
  Properties getAllTranslations(GrailsParameterMap params, HttpServletRequest request) {
    Locale locale = localeService.prepareLocale(params, request)
    Properties keys = messageSource.withTraits(MessagePropertiesTrait).getMessageKeys(locale)

    //def jsKeys = keys.findAll { code, value -> ((String) code).startsWith('js.') }
    //render jsKeys as JSON

    return keys
  }
}

LocaleService.groovy

package myproject

import grails.transaction.Transactional
import grails.web.servlet.mvc.GrailsParameterMap
import org.springframework.web.servlet.support.RequestContextUtils

import javax.servlet.http.HttpServletRequest

@Transactional
class LocaleService {

  public static final String DEFAULT_LANG = 'es'
  public static final String PARAM_LANG_KEY = 'langKey'
  public static final String COOKIE_LANG_KEY = 'language'

  Locale prepareLocale(GrailsParameterMap params, HttpServletRequest request) {
    Locale locale = null
    int i = 0

    List<String> langStrings = new ArrayList<>()
    langStrings.add(params.get(PARAM_LANG_KEY) as String)
    langStrings.add(request.cookies.find { COOKIE_LANG_KEY == it.name }?.value)

    while ((locale == null) && (i < langStrings.size())) {
      String str = langStrings.get(i)
      if (str) {
        try {
          locale = new Locale(str)
        } catch (Exception ex) {
          ex.printStackTrace()
        }
      }

      i++
    }

    if (locale == null) {
      try {
        // From Request
        locale = RequestContextUtils.getLocale(request)
      } catch (Exception e) {
        // Default
        locale = new Locale(DEFAULT_LANG)
      }
    }

    return locale
  }
}

Helpers.groovy

Create this file at utils/myproject :

package myproject

import groovy.transform.CompileStatic
import groovy.transform.TypeCheckingMode

@CompileStatic(TypeCheckingMode.SKIP)
trait MessagePropertiesTrait {
  Properties getMessageKeys(Locale locale) {
    this.getMergedProperties(locale).properties
  }

  Properties getPluginMessageKeys(Locale locale) {
    this.getMergedPluginProperties(locale).properties
  }
}

UrlMappings.groovy

Add follow URL mapping:

"/i18n/$langKey?(.$format)?"(controller: 'i18n', action: 'index')

Usage

URL

http://localhost:8080/i18n # Default language
http://localhost:8080/i18n/.json # Default language

http://localhost:8080/i18n/en.json
http://localhost:8080/i18n/en

http://localhost:8080/i18n/es.json
http://localhost:8080/i18n/es

Cookie

Set a Cookie named language with the language ( es , en , ...) and call http://localhost:8080/i18n or http://localhost:8080/i18n/.json