Globalization And Cultures

When DotVVM serializes the viewmodel, it includes an information about the current thread culture which was used to process the request.

If you use any control which works with numeric or date values (e.g. Literal with its FormatString property), the page needs to know which culture should be used in order to apply the correct format.

Default Culture

In the DotVVM configuration, you can specify the default culture which is used for all requests. The best way is to set this value in the DotvvmStartup.cs file using the following code:

config.DefaultCulture = "en-US";

Switching Cultures

The way how cultures are switched was different in DotVVM 1.1 and didn't handle asynchronous methods correctly in some cases.

If your website supports multiple languages and cultures, you need to store the language the user has selected somewhere. Whichever method you use (cookies, URL, database...), you need to tell DotVVM at the beginning of the request processing, which culture is used for the particular HTTP request.

When you register the route, you can specify a custom presenter factory and use Localization Presenter.

The easiest way is to use route parameters to persist the current culture. The URL format will be /en/Home.

config.RouteTable.Add("Home", "{Lang}/home", "Views/Home.dothtml", new { Lang = "en" }, 
    presenterFactory: LocalizablePresenter.BasedOnParameter("Lang"));

Alternatively, you can use a query string parameter - the URL format will be /Home?lang=en in this case:

config.RouteTable.Add("Home", "home", "Views/Home.dothtml", 
    presenterFactory: LocalizablePresenter.BasedOnQuery("lang"));

The localizable presenter will use the culture from the route or query string parameter and sets the Thread.CurrentThread.CurrentCulture to this culture for the HTTP request. The same culture is set for all async calls and is used even if the part of the method after an awaited call is executed on a different thread.

The BasedOnParameter and BasedOnQuery methods have a second optional parameter which specifies whether a redirect should be performed when the specified culture was not found. It is true by default.

If you need to implement another way of handling the culture, see Localization Presenter chapter for more details.

The Context.ChangeCurrentCulture method used in DotVVM 1.1 and older versions was removed.