MVC data annotation layer: where to put the set CurrentUICulture statement? - asp.net-mvc

Question

I am getting crazy with the localization of an MVC application.
After a recent question of mine I have followed this approach:
The language is stored in Session["lang"]
Each controller inherits from my own BaseController, which overrides OnActionExecuting, and in this method reads the Session and sets CurrentCulture and CurrentUICulture
This works great, until the Data Annotation Layer comes in. It seems like it gets called BEFORE the action itself is executed, and therefore it always gets the error messages in the default language!
The fields declarations go like this:
[Required(ErrorMessageResourceName = "validazioneRichiesto", ErrorMessageResourceType = typeof(Resources.Resources))]
public string nome { get; set; }
So, is there any reasonable place where I can put the call?
I initialize the Data Annotation Model Binder in my Controller constructor.
public CardController() : base() {
ModelBinders.Binders.DefaultBinder =
new Microsoft.Web.Mvc.DataAnnotations.DataAnnotationsModelBinder();
}
So, since Session is always null in the controller's constructor, and the action override is called AFTER the data annotation has validated the fields, where can I possibly set the CurrentCulture and CurrentUICulture to get localized errors?
I tried putting the CurrentCulture and CurrentUiCulture in Application_* (e.g. Application_AcquireRequestState or Application_PreRequestHandlerExecute) seems to have no effect...

Answer 1

As the culture is a global user setting, I am using it in the global.asax.cs file in the Application_BeginRequest method.
It does the work for me (using cookies) but the Session is also available there.
EDIT:
/by Brock Allen:
http://www.velocityreviews.com/forums/t282576-aspnet-20-session-availability-in-globalasax.html/
Session is available in PreRequesthandlerExecute.
The problem is that your code is being executed for every request into the server, and some requests (like ones for WebResourxe.axd) don't utlilize
Session (because the handler doesn't implement IRequireSessionState). So change your code to only access Session if that request has access to it.
Change your code to do this:
protected void Application_PreRequestHandlerExecute(Object sender, EventArgs e)
{
if (Context.Handler is IRequiresSessionState || Context.Handler is IReadOnlySessionState)
SetCulture();
}
Anyway, not sure if it works with mvc

Answer 2

After reading your question more carefully, I think that your problem is more in the way the resources are compiled.
Check in the Resource.resx properties, find Build Action and set it to Embedded Resource
Also change Custom Tool to PublicResXFileCodeGenerator
alt text http://img208.imageshack.us/img208/2126/captuream.png
I have tested a mini solution and works perfectly.
If you have more problem, I can send the example to you.

Answer 3

Another approach you can use is to put the lang in the URL, with this benefits:
The site is spidered by search engines in different languages
The user can send a URL to a friend in the selected language
To do this, use the Application_BeginRequest method in Global.asax
Sub Application_BeginRequest(ByVal sender As Object, ByVal e As EventArgs)
Dim lang As String
If HttpContext.Current.Request.Path.Contains("/en/") Then
lang = "en"
Else
lang = "es"
End If
Thread.CurrentThread.CurrentUICulture = CultureInfo.GetCultureInfo(lang)
Thread.CurrentThread.CurrentCulture = CultureInfo.CreateSpecificCulture(lang)
End Sub
See this question for more info on how to implement it

Answer 4

The OP posted the final solution as the following, thanks to the accepted answer by twk:
void Application_PreRequestHandlerExecute(object sender, EventArgs e) {
if (Context.Handler is IRequiresSessionState ||
Context.Handler is IReadOnlySessionState) {
if (Session["lang"] == null) {
Session["lang"] = "it";
}
if (Request.QueryString["lang"] == "it" || Request.QueryString["lang"] == "en") {
Session["lang"] = Request.QueryString["lang"];
}
string lang1 = Session["lang"].ToString();
string lang2 = Session["lang"].ToString().ToUpper();
if (lang2 == "EN")
lang2 = "GB";
System.Threading.Thread.CurrentThread.CurrentCulture =
System.Globalization.CultureInfo.CreateSpecificCulture(lang1 + "-" + lang2);
System.Threading.Thread.CurrentThread.CurrentUICulture =
System.Globalization.CultureInfo.CreateSpecificCulture(lang1 + "-" + lang2);
}
}