AugusteVN.HttpClient.Delegator 1.0.2

Named HttpClient with Delegator

Adds a named HttpClient, a delegator that can add headers to the request, a keyed singleton to share values with the delegator and a resolver for that keyed singleton. The interface of the resolver 'IHttpClientFactory<T>' implements the original 'IHttpClientFactory', hides its methods but uses those under the hood.

It contains what was covered in this video: Authorize HttpClient with Delegating Handler C# .NET

Sandbox, work in progress

builder.Services.AddHttpClient(nameof(TUtils), client => client.BaseAddress = new Uri("https://localhost:3000"))
    .AddDelegator<TUtils>();

builder.Services.AddHttpClient(nameof(TPetService), client => client.BaseAddress = new Uri("https://localhost:3005"))
    .AddDelegator<TPetService>();

builder.Services.AddHttpClientStateResolver<NewsletterSubscribersHttpClient>(nameof(TUtils));

builder.Services.AddScoped<AuthService>();
builder.Services.AddScoped<PetService>();
builder.Services.AddScoped<NewsletterSubscribersHttpClient>();

var app = builder.Build();

app.MapGet("/", (AuthService auth, NewsletterSubscribersHttpClient news, PetService pet) =>
{
    auth.AuthorizeClient("<access-token>");
    auth.PrintLocalState(); // AuthService Local: client name: [TUtils], headers: [[x-news, bar]]
    auth.PrintGlobalState(); // AuthService Global: client names: [TPetService,TUtils], headers: [[x-bar, foo],[Authorization, Bearer <access-token>]]
    
    news.PrintLocalState(); // Newsletter Local: client name: [TUtils], headers: [[x-news, bar]]
    news.PrintGlobalState(); // Newsletter Global: client names: [TPetService,TUtils], headers: [[x-bar, foo],[Authorization, Bearer <access-token>]]

    pet.PrintLocalState(); // PetService Local: client name: [TPetService], headers: [[x-pet-service, foo]]
    pet.PrintGlobalState(); // PetService Global: client names: [TPetService,TUtils], headers: [[x-bar, foo],[Authorization, Bearer <access-token>]]
    Results.Ok();
});

app.Run();

public record TUtils;
public record TPetService;

public class AuthService
{
    private readonly HttpClient _httpClient;
    private readonly IHttpClientFactory<TUtils> _httpState;
    public AuthService(IHttpClientFactory<TUtils> httpState)
    {
        _httpClient = httpState.CreateClient();
        _httpState = httpState;
    }

    public void AuthorizeClient(string? token)
    {
        _httpState.Global.AddHeader("Authorization", $"Bearer {token}");
    }

    public void PrintLocalState()
    {
        Console.WriteLine($"AuthService Local: client name: [{_httpState.Local.ClientName}], headers: [{string.Join(',', _httpState.Local.Headers)}]");
    }

    public void PrintGlobalState()
    {
        Console.WriteLine($"AuthService Global: client names: [{string.Join(',', _httpState.Global.ClientNames)}], headers: [{string.Join(',', _httpState.Global.Headers)}]");
    }
}

public class PetService
{
    private readonly HttpClient _httpClient;
    private readonly IHttpClientFactory<TPetService> _httpState;
    public PetService(IHttpClientFactory<TPetService> httpState)
    {
        _httpClient = httpState.CreateClient();
        _httpState = httpState;
        _httpState.Local.AddHeader("x-pet-service", "foo");
    }

    public void PrintLocalState()
    {
        Console.WriteLine($"PetService Local: client name: [{_httpState.Local.ClientName}], headers: [{string.Join(',', _httpState.Local.Headers)}]");
    }

    public void PrintGlobalState()
    {
        Console.WriteLine($"PetService Global: client names: [{string.Join(',', _httpState.Global.ClientNames)}], headers: [{string.Join(',', _httpState.Global.Headers)}]");
    }
}

public class NewsletterSubscribersHttpClient
{
    private readonly HttpClient _httpClient;
    private readonly IHttpClientFactory<NewsletterSubscribersHttpClient> _httpState;
    public NewsletterSubscribersHttpClient(IHttpClientFactory<NewsletterSubscribersHttpClient> httpState)
    {
        _httpClient = httpState.CreateClient();
        _httpState = httpState;
        _httpState.Local.AddHeader("x-news", "bar");
        _httpState.Global.AddHeader("x-bar", "foo");
    }

    public void PrintLocalState()
    {
        Console.WriteLine($"Newsletter Local: client name: [{_httpState.Local.ClientName}], headers: [{string.Join(',', _httpState.Local.Headers)}]");
    }

    public void PrintGlobalState()
    {
        Console.WriteLine($"Newsletter Global: client names: [{string.Join(',', _httpState.Global.ClientNames)}], headers: [{string.Join(',', _httpState.Global.Headers)}]");
    }
}