I am trying to use the RouteDataRequestCultureProvider in a new ASP.NET Core 2.2 MVC project.
I've read the Microsoft documentation on Routing in ASP.NET Core to understand the changes introduced in 2.2, but I don't understand why "culture" isn't recognized as an ambient value for URL generation.
I updated ConfigureServices in Startup.cs to include the settings:
var supportedCultres = new[] { new CultureInfo("en"), new CultureInfo("fr") };
services.Configure<RequestLocalizationOptions>(options =>
{
options.DefaultRequestCulture = new Microsoft.AspNetCore.Localization.RequestCulture("en");
options.SupportedCultures = supportedCultres;
options.SupportedUICultures = supportedCultres;
options.RequestCultureProviders = new[] { new RouteDataRequestCultureProvider { Options = options } };
});
And I modified the app and default route in Configure to use a "culture" path segment:
var locOptions = app.ApplicationServices.GetService<IOptions<RequestLocalizationOptions>>().Value;
app.UseRequestLocalization(locOptions);
app.UseMvc(routes =>
{
routes.MapRoute(
name: "default",
template: "{culture:regex(^(en|fr)$)}/{controller=Home}/{action=Index}/{id?}");
});
This route will resolve to HomeController.Index() when I navigate to either /en or /fr as expected, but any links to other actions with the Anchor Tag Helper will render as <a href=""> (including the Privacy link generated by the scaffold).
Turning off EnableEndpointRouting causes the Anchor Tag Helper to work again:
services.AddMvc(opts => { opts.EnableEndpointRouting = false; })
.SetCompatibilityVersion(CompatibilityVersion.Version_2_2);
Adding an explicit asp-route-culture value also works:
<a asp-route-culture="en" asp-controller="Home" asp-action="About">About</a>
But I don't understand why either change is required since the "culture" route value is already present in the RouteData.Values collection and was automatically used by the anchor tag helper with the previous routing model. These are valid routes to actions, so why is the URL generation failing when the route includes a culture?