fix for GRAILS-7416 "switching the apps locale with ?lang=XX Parameter is not working on the index.gsp page"

Author: graemerocher

grails-plugin-i18n/src/main/groovy/org/codehaus/groovy/grails/plugins/i18n/I18nGrailsPlugin.groovy

@@ -85,11 +85,11 @@ class I18nGrailsPlugin {
             }
         }
 
+        localeResolver(SessionLocaleResolver)
         localeChangeInterceptor(ParamsAwareLocaleChangeInterceptor) {
             paramName = "lang"
+            localeResolver = ref("localeResolver")
         }
-
-        localeResolver(SessionLocaleResolver)
     }
 
     @CompileStatic

grails-web-common/src/main/groovy/org/codehaus/groovy/grails/web/i18n/ParamsAwareLocaleChangeInterceptor.groovy

@@ -16,6 +16,9 @@
 package org.codehaus.groovy.grails.web.i18n
 
 import groovy.transform.CompileStatic
+import org.springframework.beans.factory.annotation.Autowired
+import org.springframework.web.servlet.DispatcherServlet
+import org.springframework.web.servlet.LocaleResolver
 
 import javax.servlet.http.HttpServletRequest
 import javax.servlet.http.HttpServletResponse
@@ -40,11 +43,18 @@ class ParamsAwareLocaleChangeInterceptor extends LocaleChangeInterceptor {
 
     String paramName = DEFAULT_PARAM_NAME
 
+    LocaleResolver localeResolver
+
     void setParamName(String name) {
         paramName = name
         super.setParamName name
     }
 
+    @Autowired(required = false)
+    void setLocaleResolver(LocaleResolver localeResolver) {
+        this.localeResolver = localeResolver
+    }
+
     @Override
     boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) {
 
@@ -63,6 +73,10 @@ class ParamsAwareLocaleChangeInterceptor extends LocaleChangeInterceptor {
                 localeParam = ((Object[])localeParam)[0]
             }
             def localeResolver = RequestContextUtils.getLocaleResolver(request)
+            if(localeResolver == null) {
+                localeResolver = this.localeResolver
+                request.setAttribute(DispatcherServlet.LOCALE_RESOLVER_ATTRIBUTE, localeResolver)
+            }
             def localeEditor = new LocaleEditor()
             localeEditor.setAsText localeParam?.toString()
             localeResolver?.setLocale request, response, (Locale)localeEditor.value