Resources files with SignalrR - localization

Question

I have a project mvc 4 c# I'm using resource files for localization. I have action to change the culture
public ActionResult ChangeCulture(string lang, string returnUrl)
{
if (lang.Equals("he-IL"))
{
CultureInfo ci = new CultureInfo(lang);
ci.DateTimeFormat.ShortDatePattern = "dd/MM/yy";
ci.DateTimeFormat.LongDatePattern = "dd/MM/yy";
ci.DateTimeFormat.LongTimePattern = "HH:mm";
ci.DateTimeFormat.ShortTimePattern = "HH:mm";
ci = new CultureInfo(lang);
Thread.CurrentThread.CurrentUICulture = ci;
Thread.CurrentThread.CurrentCulture = CultureInfo.CreateSpecificCulture(ci.Name);
}
else if (lang.Equals("en-US"))
{
CultureInfo ci = new CultureInfo(lang);
ci = new CultureInfo(lang);
Thread.CurrentThread.CurrentUICulture = ci;
Thread.CurrentThread.CurrentCulture = CultureInfo.CreateSpecificCulture(ci.Name);
}
else
{
return new HttpStatusCodeResult(404);
}
return Redirect(returnUrl);
}
in the view I get the text from resource and it's working good.
<div>#(ViewRes.GlobalResource.Hello)</div>
but when I return text from SignalR hub it's always the same language. why?

Answer 1

SignalR does not localize your text within it's stack, you have to select the correctly localized text and return that string yourself. This should be as easy as requesting your resource from a ResourceManager and letting it select the correctly localized text for you. A really simple example of that looks something like this:
public string YourHubMethod()
{
ResourceManager resourceManager = new ResourceManager("YourNamespace.YourResourcesName",
typeof(YourHubType).Assembly);
return resourceManager.GetString("SomeResourceName");
}
Update:
Now that you've provided some more information about how you remember the current culture between requests for your web application in the comments (you use a cookie) I can give you more information on how to make this transfer over to SignalR.
You'll first want to override your Hub's OnConnected property and there you can extract the cookie value and store it in SignalR connection state like so:
public override Task OnConnected()
{
Client.Culture = Context.Request.Cookies["YourCultureCookieName"];
return base.OnConnected();
}
Once it's stored in the client state, you can now build a HubPipelineModule that looks for that state and sets the culture for each logical SignalR request:
public class CallerCulturePipelineModule : HubPipelineModule
{
protected override bool OnBeforeIncoming(IHubIncomingInvokerContext context)
{
// Use the value we stored in the Culture property of the caller's state when they connected
CultureInfo callerCultureInfo = new CultureInfo(context.Hub.Context.Caller.Culture);
Thread.CurrentThread.CurrentUICulture = callerCultureInfo;
Thread.CurrentThread.CurrentCulture = callerCultureInfo;
return base.OnBeforeIncoming(context);
}
}
You then need to make sure to register the pipeline module as part of your Application_Start:
GlobalHost.HubPipeline.AddModule(new CallerCulturePipelineModule());
Finally, if the user changes their culture while they're already connected you would need to update their connection state with the newly selected value (since they're not going to reconnect).There's actually no way to modify connection state outside the hub itself, so you would need to actually get the IHubContext for your hub and update the client through an explicit callback to the client inside of your existing MVC controller's ChangeCulture method. To do this I would suggest you pass the connection ID to ChangeCulture as an optional query string variable (since the user might not be connected to your hub all the time?) and then use that to call back to the client:
string connectionId = <get connectionId from request here>;
IHubContext yourHubContext GlobalHost.GetHubContext<YourHub>();
yourHubContext.Client(connectionId).UpdateCultureState(lang);
And then on the client side you just update the state in JavaScript:
yourHubProxy.client.updateCultureState = function(lang)
{
yourHubProxy.state.culture = lang;
}