BlazorServerUrlRequestCultureProvider

Localization scheme based on the URL path that works with Blazor Server (WebSockets) and Blazor Static SSR.

How it works

1. Set the culture on the first HTTP request
2. On blazor negotiate:
   • Check the websocket request referrer; in our case /{TWO_LETTER_ISO_LANGUAGE_NAME}/{SOME_URI}
   • Change the culture base on the websocket request referrer
   • Store the connection token and culture key/value pair
3. On Blazor heartbeat:
   • Using the connection token, retrieve the stored culture
   • Change the culture based on the stored value
4. When closing the websocket: Remove the stored connection token and culture key/value pair

How to use this package

Add the NuGet package to your Blazor Server project:

dotnet add package BlazorServerUrlRequestCultureProvider

Program.cs

In your Program.cs file, add the following code:

var builder = WebApplication.CreateBuilder(args);

// Add services to the container.
builder.Services.AddRazorComponents()
    .AddInteractiveServerComponents();

builder.Services.AddLocalization();

builder.Services.Configure<RequestLocalizationOptions>(options =>
{
    // Remove the default providers
    // 1. QueryStringRequestCultureProvider
    // 2. CookieRequestCultureProvider
    // 3. AcceptLanguageHeaderRequestCultureProvider
    options.RequestCultureProviders.Clear();

    IList<CultureInfo> supportedCultures = [new("en"), new("fr")];

    options.DefaultRequestCulture = new RequestCulture("en");
    options.SupportedCultures = supportedCultures;
    options.SupportedUICultures = supportedCultures;

    options.ApplyCurrentCultureToResponseHeaders = true;

    // Configure globalization for static server-side rendering (static SSR)
    options.RequestCultureProviders.Insert(0, new UrlRequestCultureProvider(options));

    // Configure globalization for interactive server-side rendering (interactive SSR) using Blazor Server.
    options.RequestCultureProviders.Insert(1, new BlazorNegotiateRequestCultureProvider(options));
});

// ...

var app = builder.Build();

// Configure the HTTP request pipeline.
if (!app.Environment.IsDevelopment())
{
    app.UseExceptionHandler("/Error", createScopeForErrors: true);
    // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
    app.UseHsts();
}

app.UseHttpsRedirection();

app.UseStaticFiles();

app.UseRequestLocalization();
// app.UseRequestLocalizationInteractiveServerRenderMode(useCookie: false); // Server-side ConcurrentDictionary storage
app.UseRequestLocalizationInteractiveServerRenderMode(useCookie: true); // Client-side cookie storage

app.UseAntiforgery();

app.MapRazorComponents<App>()
    .AddInteractiveServerRenderMode();

app.Run();

Index.razor

@page "/"
@page "/fr"
@page "/en"
@inject IStringLocalizer<App> Localizer


<h1>@Localizer["Hello, world!"]</h1>

@Localizer["Welcome to your new app."]

Counter.razor

@page "/en/counter"
@page "/fr/compteur"

@inject IStringLocalizer<App> Localizer

<h1>@Localizer["Counter"]</h1>

<p>@Localizer["Current count:"] @currentCount</p>

<button class="btn btn-primary" @onclick="IncrementCount">@Localizer["Click me"]</button>

@code {
    private int currentCount = 0;

    private void IncrementCount()
    {
        currentCount++;
    }
}