Get CultureInfo from current visitor and setting resources based on that?

Question

How can I (in ASP .NET MVC) get the CultureInfo of the current visitor (based on his/her browser languages)?

I have no idea where to start. I tried looking into the "Accept-Languages" header sent by the browser. But is that the best way of doing it?

Answer 1

Request.UserLanguages is the property you're looking for. Just keep in mind that this array may contain arbitrary (even non-exsitent) languages as set by request headers.

UPDATE

Example:

// Get Browser languages.
var userLanguages = Request.UserLanguages;
CultureInfo ci;
if (userLanguages.Count() > 0)
{
    try
    {
        ci = new CultureInfo(userLanguages[0]);
    }
    catch(CultureNotFoundException)
    {
         ci = CultureInfo.InvariantCulture;
    }
}
else
{
    ci = CultureInfo.InvariantCulture;
}
// Here CultureInfo should already be set to either user's prefereable language
// or to InvariantCulture if user transmitted invalid culture ID

Answer 2

Asp.Net Core version: using RequestLocalization ie the culture is retrieved form the HTTP Request.

in Startup.cs - Configure

app.UseRequestLocalization();

Then in your Controller/Razor Page.cs

var locale = Request.HttpContext.Features.Get<IRequestCultureFeature>();
var BrowserCulture = locale.RequestCulture.UICulture.ToString();

Answer 3

You can use code similar to the following to get various details from your user (including languages):

MembershipUser user = Membership.GetUser(model.UserName);
string browser = HttpContext.Request.Browser.Browser;
string version = HttpContext.Request.Browser.Version;
string type = HttpContext.Request.Browser.Type;
string platform = HttpContext.Request.Browser.Platform;
string userAgent = HttpContext.Request.UserAgent;
string[] userLang = HttpContext.Request.UserLanguages

Answer 4

It appears Request.UserLanguages is not available in later mvc versions (Asp.net core mvc 2.0.2 didn't have it.)

I made an extension method for HTTPRequest. Use it as follows:

var requestedLanguages = Request.GetAcceptLanguageCultures();

The method will give you the cultures from the Accept-Language header in order of preference (a.k.a. "quality").

public static class HttpRequestExtensions
{
    public static IList<CultureInfo> GetAcceptLanguageCultures(this HttpRequest request)
    {
        var requestedLanguages = request.Headers["Accept-Language"];
        if (StringValues.IsNullOrEmpty(requestedLanguages) || requestedLanguages.Count == 0)
        {
            return null;
        }

        var preferredCultures = requestedLanguages.ToString().Split(',')
            // Parse the header values
            .Select(s => new StringSegment(s))
            .Select(StringWithQualityHeaderValue.Parse)
            // Ignore the "any language" rule
            .Where(sv => sv.Value != "*")
            // Remove duplicate rules with a lower value
            .GroupBy(sv => sv.Value).Select(svg => svg.OrderByDescending(sv => sv.Quality.GetValueOrDefault(1)).First())
            // Sort by preference level
            .OrderByDescending(sv => sv.Quality.GetValueOrDefault(1))
            .Select(sv => new CultureInfo(sv.Value.ToString()))
            .ToList();

        return preferredCultures;
    }
}

Tested with ASP.NET Core MVC 2.0.2

It's similar to @mare's answer, but a bit more up-to-date and the q (quality) is not ignored. Also, you may want to append the CultureInfo.InvariantCulture to the end of the list, depending on your usage.