Call unauthorized controller in Blazor scoped HttpClient

Question

So in Blazor Web Assembly (with ASP.NET Scoped) we have this great new HttpClient:

builder.Services.AddHttpClient(
    "ServerAPI", 
    client => client.BaseAddress = new Uri(builder.HostEnvironment.BaseAddress))
    .AddHttpMessageHandler<BaseAddressAuthorizationMessageHandler>();

builder.Services
    .AddScoped(sp => sp.GetRequiredService<IHttpClientFactory>().CreateClient("ServerAPI"));

But I have some controller, that by design is supposed to be called before user authentication, thus I don't have token yet.

@inject HttpClient HttpClient;
// (... irrelevant razor code)
await HttpClient.PostAsync("UnauthorizedController", someData);

and I got exception: Microsoft.AspNetCore.Components.WebAssembly.Authentication.AccessTokenNotAvailableException

And the question is, how should those unauthorized request be handled?

Answer 1

You don't need to have only one HttpClient in your app.

Register 2 named clients:

builder.Services.AddHttpClient(
    "ServerAPI", 
    client => client.BaseAddress = new Uri(builder.HostEnvironment.BaseAddress))
    .AddHttpMessageHandler<BaseAddressAuthorizationMessageHandler>();

builder.Services.AddHttpClient(
    "UnauthorizedServerAPI", 
    client => client.BaseAddress = new Uri(builder.HostEnvironment.BaseAddress));

In your blazor component inject IHttpClientFactory and create client when needed:

@inject IHttpClientFactory _clientFactory;
// (... irrelevant razor code)

var client = _httpClientFactory.CreateClient("UnauthorizedServerAPI");
await client.PostAsync("UnauthorizedController", someData);